https://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392en-USTelligent Community 12https://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392Fri, 03 May 2019 07:24:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:a07923ef-18dd-4578-aaea-9f23a5fea710Matthttps://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392#commentsCurrent Revision posted to Documents by Matt on 5/3/2019 7:24:00 AM<br /> <div style="background:#ffffff;border:1px solid #dadada;margin:0;padding:14px 16px 16px 18px;vertical-align:top;"> <div style="display:inline-block;float:left;padding:0px 25px 8px 0px;"><a href="/challengesprojects/element14-presents/" data-e14adj="t"><img alt="image" src="/e14/assets/legacy/2018/e14PresentsJune818.png" width="180px" /></a></div> <div style="display:inline-block;vertical-align:top;width:70%;"> <p style="margin:0;"><span style="font-size:12pt;"><strong>Multi-Line Telephone Intercom</strong></span></p> <p style="margin:0;"><span><a class="jivecontainerTT-hover-container jive-link-community-small" href="/challengesprojects/element14-presents/" data-e14adj="t">element14 Presents</a></span>&nbsp; <strong>|</strong>&nbsp;&nbsp; <a class="jive-link-wiki-small" href="/challengesprojects/element14-presents/vcp-program/w/documents/4139/vcp-biography-derek" data-e14adj="t">Derek Brodeur&#39;s VCP Profile</a>&nbsp; <strong>|</strong>&nbsp; <a class="jivecontainerTT-hover-container jive-link-community-small" href="/challengesprojects/element14-presents/project-videos/" data-e14adj="t">Project Videos</a></p> </div> </div> <p style="margin:0;padding:0px;">&nbsp;</p> <p style="margin:0;padding:0px;">&nbsp;</p> <table style="display:block;margin:0 auto;width:80%;"> <tbody> <tr> <td style="padding-bottom:12px;"><span><a href="https://www.youtube.com/watch?v=BGbmFF56iH8">www.youtube.com/watch</a></span></td> </tr> <tr> <td style="text-align:justify;"> <p style="background-color:#e9f6fc;border:1px solid #b8d7e5;margin:0;max-width:634px;padding:8px;"><span style="color:black;font-family:&#39;Arial&#39;,sans-serif;">Modern smart phones have become so ubiquitous these days that old analog phones are getting left in the dust. However, you may still have a few of these old phones hanging around your house collecting cobwebs or you may have seen some lingering on the shelves at your local thrift shop. Now&rsquo;s your chance to put them to good use. In this video, Derek takes you back to a time when stretching a phone cord across the room was the norm by creating a 4-line telephone intercom system with basic ringing capability. The circuit surrounds a DTMF decoder IC which handles keypress detection, a simple AC inverter to handle the ringing and a current source which allows analog communication between multiple phones.</span></p> </td> </tr> </tbody> </table> <p style="margin:0;padding:0px;">&nbsp;</p> <p style="margin:0;padding:0px;">&nbsp;</p> <h2><span style="color:#3334ca;">Bill of Materials</span></h2> <p style="margin:0;padding:0px;">&nbsp;</p> <table class="jiveBorder" style="border:1px solid #C6C6C6;" border="1" width="100%"> <thead> <tr> <th style="background-color:#f2f2f2;border:1px solid #C6C6C6;color:#505050;padding:6px;text-align:left;">Product Name</th> <th style="background-color:#f2f2f2;border:1px solid #C6C6C6;color:#505050;padding:6px;text-align:left;">Manufacturer</th> <th style="background-color:#f2f2f2;border:1px solid #C6C6C6;color:#505050;padding:6px;text-align:left;">Quantity</th> <th style="background-color:#f2f2f2;border:1px solid #C6C6C6;color:#505050;padding:6px;text-align:left;"><span><a id="e14-product-link-90860" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="button" href="https://referral.element14.com/OrderCodeView?fsku=2808967,1106105,2760747,1652293,7940294,NA~5&nsku=44AC2327,60K5115,83X9336,98H0572,13J1639,67K9351~5&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_BUY_KIT" class="e14-embedded e14_shopping-cart-far e14-button" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('90860'));" data-farnell="2808967~1,1106105~1,2760747~1,1652293~1,7940294~1,NA~5" data-newark="44AC2327~1,60K5115~1,83X9336~1,98H0572~1,13J1639~1,67K9351~5" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Kit</a> </span></th> </tr> </thead> <tbody> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">0.1uF 25v Capacitor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-fe5a4" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('fe5a4'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">1uF 50v Capacitor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-66c5b" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('66c5b'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">20pF Capacitor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-37c1e" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('37c1e'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">2.2uF 250V Capacitor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-93752" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=2808967&nsku=44AC2327&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('93752'));" data-farnell="2808967~1" data-newark="44AC2327~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">1N4001 Diode</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-ca3f4" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('ca3f4'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">IRF540N N-Channel MOSFET</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-ab5e1" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('ab5e1'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">2N2904 NPN Transistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-938a7" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('938a7'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">HT9170D DTMF Decoder</td> <td style="border:1px solid #C6C6C6;padding:6px;">Holtek</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-f6633" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('f6633'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">CD4047 Multivibrator</td> <td style="border:1px solid #C6C6C6;padding:6px;">Texas Instruments</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-8cb12" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=1106105&nsku=60K5115&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('8cb12'));" data-farnell="1106105~1" data-newark="60K5115~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">DC/DC Converter 5v / 1A</td> <td style="border:1px solid #C6C6C6;padding:6px;">RECOM</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-df1c5" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=2760747&nsku=83X9336&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('df1c5'));" data-farnell="2760747~1" data-newark="83X9336~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">LM317T Adjustable Voltage Regulator</td> <td style="border:1px solid #C6C6C6;padding:6px;">ON Semiconductor</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-b2e28" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=1652293&nsku=98H0572&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('b2e28'));" data-farnell="1652293~1" data-newark="98H0572~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">3.579545MHz Crystal</td> <td style="border:1px solid #C6C6C6;padding:6px;">ABL</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-e9412" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=7940294&nsku=13J1639&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('e9412'));" data-farnell="7940294~1" data-newark="13J1639~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">DPDT Relay</td> <td style="border:1px solid #C6C6C6;padding:6px;">OMRON</td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-cb13b" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=NA~5&nsku=67K9351~5&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('cb13b'));" data-farnell="NA~5" data-newark="67K9351~5" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">75k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-6d988" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('6d988'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">220 Ohm 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-04264" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('04264'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">22 Ohm 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-5d793" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('5d793'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">56k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-1c5f0" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('1c5f0'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">100k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-b7ff4" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('b7ff4'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">150k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-bc79f" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('bc79f'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">68k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-1bc10" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('1bc10'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">1k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-16904" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('16904'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">300k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-eb727" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('eb727'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> </tbody> </table> <p style="margin:0;padding:0px;">&nbsp;</p> <p style="margin:0;padding:0px;">&nbsp;</p> <h2><span style="color:#3334ca;">Additional Parts:</span></h2> <p style="margin:0;padding:0px;">&nbsp;</p> <table class="jiveBorder" style="border:1px solid #000000;width:100%;" border="1"> <thead> <tr> <th style="background-color:#6690bc;border:1px solid #000000;color:#ffffff;padding:2px;text-align:left;" valign="middle"><strong>Product Name</strong></th> <th style="background-color:#6690bc;border:1px solid #000000;color:#ffffff;padding:2px;text-align:left;" valign="middle"><strong>Quantity<br /></strong></th> </tr> </thead> <tbody> <tr> <td style="border:1px solid #000000;padding:2px;">RJ11 Telephone Jack - right angle</td> <td style="border:1px solid #000000;padding:2px;">5</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">120V / 18V Center Tap Transformer</td> <td style="border:1px solid #000000;padding:2px;">1</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">Prototyping PCB</td> <td style="border:1px solid #000000;padding:2px;">2</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">PCB Standoffs + Screws</td> <td style="border:1px solid #000000;padding:2px;">4</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">Metal Enclosure</td> <td style="border:1px solid #000000;padding:2px;">1</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">SOP-20 Breakout board</td> <td style="border:1px solid #000000;padding:2px;">1</td> </tr> </tbody> </table> <div class="migration-injected-attachments"> <div style="font-weight:bold;margin:15px 0 5px 0;">Attachments:</div> <div></div> <table style="border:0;"> <tbody> <tr> <td width="160"><span id="attid_https://www.element14.com/community/api/core/v3/attachments/280953" class="_se_attachment"><a href="https://community.element14.com/cfs-file/__key/communityserver-wikis-components-files/00-00-00-03-81/Derek-Brodeur-_2D00_-Schematic.pdf">community.element14.com/.../Derek-Brodeur-_2D00_-Schematic.pdf</a></span></td> <td><span style="font-size:80%;">Derek Brodeur - Schematic.pdf</span></td> </tr> </tbody> </table> </div><div style="clear:both;"></div> <div style="font-size: 90%;">Tags: derek_episode, derek_brodeur, plain old telephone, e14presents_derekbrodeur, multi-line, intercom, telephone intercom, telephone, pots intercom, friday_release</div> https://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392/revision/3Thu, 27 Jul 2023 14:57:08 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:a07923ef-18dd-4578-aaea-9f23a5fea710cstantonhttps://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392#commentsRevision 3 posted to Documents by cstanton on 7/27/2023 2:57:08 PM<br /> <div style="background:#ffffff;border:1px solid #dadada;margin:0;padding:14px 16px 16px 18px;vertical-align:top;"> <div style="display:inline-block;float:left;padding:0px 25px 8px 0px;"><a href="/challengesprojects/element14-presents/"><img alt="image" src="/e14/assets/legacy/2018/e14PresentsJune818.png" width="180px" /></a></div> <div style="display:inline-block;vertical-align:top;width:70%;"> <p style="margin:0;"><span style="font-size:12pt;"><strong>Multi-Line Telephone Intercom</strong></span></p> <p style="margin:0;"><span><a class="jivecontainerTT-hover-container jive-link-community-small" href="/challengesprojects/element14-presents/">element14 Presents</a></span>&nbsp; <strong>|</strong>&nbsp;&nbsp; <a class="jive-link-wiki-small" href="/challengesprojects/element14-presents/vcp-program/w/documents/4139/vcp-biography-derek">Derek Brodeur&#39;s VCP Profile</a>&nbsp; <strong>|</strong>&nbsp; <a class="jivecontainerTT-hover-container jive-link-community-small" href="/challengesprojects/element14-presents/project-videos/">Project Videos</a></p> </div> </div> <p style="margin:0;padding:0px;">&nbsp;</p> <p style="margin:0;padding:0px;">&nbsp;</p> <table style="display:block;margin:0 auto;width:80%;"> <tbody> <tr> <td style="padding-bottom:12px;"><span><a href="https://www.youtube.com/watch?v=BGbmFF56iH8">www.youtube.com/watch</a></span></td> </tr> <tr> <td style="text-align:justify;"> <p style="background-color:#e9f6fc;border:1px solid #b8d7e5;margin:0;max-width:634px;padding:8px;"><span style="color:black;font-family:&#39;Arial&#39;,sans-serif;">Modern smart phones have become so ubiquitous these days that old analog phones are getting left in the dust. However, you may still have a few of these old phones hanging around your house collecting cobwebs or you may have seen some lingering on the shelves at your local thrift shop. Now&rsquo;s your chance to put them to good use. In this video, Derek takes you back to a time when stretching a phone cord across the room was the norm by creating a 4-line telephone intercom system with basic ringing capability. The circuit surrounds a DTMF decoder IC which handles keypress detection, a simple AC inverter to handle the ringing and a current source which allows analog communication between multiple phones.</span></p> </td> </tr> </tbody> </table> <p style="margin:0;padding:0px;">&nbsp;</p> <p style="margin:0;padding:0px;">&nbsp;</p> <h2><span style="color:#3334ca;">Bill of Materials</span></h2> <p style="margin:0;padding:0px;">&nbsp;</p> <table class="jiveBorder" style="border:1px solid #C6C6C6;" border="1" width="100%"> <thead> <tr> <th style="background-color:#f2f2f2;border:1px solid #C6C6C6;color:#505050;padding:6px;text-align:left;">Product Name</th> <th style="background-color:#f2f2f2;border:1px solid #C6C6C6;color:#505050;padding:6px;text-align:left;">Manufacturer</th> <th style="background-color:#f2f2f2;border:1px solid #C6C6C6;color:#505050;padding:6px;text-align:left;">Quantity</th> <th style="background-color:#f2f2f2;border:1px solid #C6C6C6;color:#505050;padding:6px;text-align:left;"><span><a id="e14-product-link-95c56" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="button" href="https://referral.element14.com/OrderCodeView?fsku=2808967,1106105,2760747,1652293,7940294,NA~5&nsku=44AC2327,60K5115,83X9336,98H0572,13J1639,67K9351~5&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_BUY_KIT" class="e14-embedded e14_shopping-cart-far e14-button" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('95c56'));" data-farnell="2808967~1,1106105~1,2760747~1,1652293~1,7940294~1,NA~5" data-newark="44AC2327~1,60K5115~1,83X9336~1,98H0572~1,13J1639~1,67K9351~5" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Kit</a> </span></th> </tr> </thead> <tbody> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">0.1uF 25v Capacitor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-d3ce7" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('d3ce7'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">1uF 50v Capacitor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-b4521" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('b4521'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">20pF Capacitor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-4c438" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('4c438'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">2.2uF 250V Capacitor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-a3d77" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=2808967&nsku=44AC2327&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('a3d77'));" data-farnell="2808967~1" data-newark="44AC2327~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">1N4001 Diode</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-214ed" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('214ed'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">IRF540N N-Channel MOSFET</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-e180b" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('e180b'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">2N2904 NPN Transistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-d4a56" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('d4a56'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">HT9170D DTMF Decoder</td> <td style="border:1px solid #C6C6C6;padding:6px;">Holtek</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-50925" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('50925'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">CD4047 Multivibrator</td> <td style="border:1px solid #C6C6C6;padding:6px;">Texas Instruments</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-1bf0a" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=1106105&nsku=60K5115&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('1bf0a'));" data-farnell="1106105~1" data-newark="60K5115~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">DC/DC Converter 5v / 1A</td> <td style="border:1px solid #C6C6C6;padding:6px;">RECOM</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-61df5" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=2760747&nsku=83X9336&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('61df5'));" data-farnell="2760747~1" data-newark="83X9336~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">LM317T Adjustable Voltage Regulator</td> <td style="border:1px solid #C6C6C6;padding:6px;">ON Semiconductor</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-474f5" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=1652293&nsku=98H0572&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('474f5'));" data-farnell="1652293~1" data-newark="98H0572~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">3.579545MHz Crystal</td> <td style="border:1px solid #C6C6C6;padding:6px;">ABL</td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-d871d" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=7940294&nsku=13J1639&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('d871d'));" data-farnell="7940294~1" data-newark="13J1639~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">DPDT Relay</td> <td style="border:1px solid #C6C6C6;padding:6px;">OMRON</td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-ea352" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=NA~5&nsku=67K9351~5&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('ea352'));" data-farnell="NA~5" data-newark="67K9351~5" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">75k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-5c3c7" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('5c3c7'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">220 Ohm 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-1b97a" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('1b97a'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">22 Ohm 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-c36ae" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('c36ae'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">56k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">2</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-17e09" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('17e09'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">100k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-847ec" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('847ec'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">150k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-289ef" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('289ef'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">68k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-fabfa" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('fabfa'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">1k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">5</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-6fa89" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('6fa89'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> <tr> <td style="border:1px solid #C6C6C6;padding:6px;">300k 1/4 Watt Resistor</td> <td style="border:1px solid #C6C6C6;padding:6px;"></td> <td style="border:1px solid #C6C6C6;padding:6px;">1</td> <td style="border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-984db" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('984db'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td> </tr> </tbody> </table> <p style="margin:0;padding:0px;">&nbsp;</p> <p style="margin:0;padding:0px;">&nbsp;</p> <h2><span style="color:#3334ca;">Additional Parts:</span></h2> <p style="margin:0;padding:0px;">&nbsp;</p> <table class="jiveBorder" style="border:1px solid #000000;width:100%;" border="1"> <thead> <tr> <th style="background-color:#6690bc;border:1px solid #000000;color:#ffffff;padding:2px;text-align:left;" valign="middle"><strong>Product Name</strong></th> <th style="background-color:#6690bc;border:1px solid #000000;color:#ffffff;padding:2px;text-align:left;" valign="middle"><strong>Quantity<br /></strong></th> </tr> </thead> <tbody> <tr> <td style="border:1px solid #000000;padding:2px;">RJ11 Telephone Jack - right angle</td> <td style="border:1px solid #000000;padding:2px;">5</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">120V / 18V Center Tap Transformer</td> <td style="border:1px solid #000000;padding:2px;">1</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">Prototyping PCB</td> <td style="border:1px solid #000000;padding:2px;">2</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">PCB Standoffs + Screws</td> <td style="border:1px solid #000000;padding:2px;">4</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">Metal Enclosure</td> <td style="border:1px solid #000000;padding:2px;">1</td> </tr> <tr> <td style="border:1px solid #000000;padding:2px;">SOP-20 Breakout board</td> <td style="border:1px solid #000000;padding:2px;">1</td> </tr> </tbody> </table> <div class="migration-injected-attachments"> <div style="font-weight:bold;margin:15px 0 5px 0;">Attachments:</div> <div></div> <table style="border:0;"> <tbody> <tr> <td width="160"><span id="attid_https://www.element14.com/community/api/core/v3/attachments/280953" class="_se_attachment"><a href="https://community.element14.com/cfs-file/__key/communityserver-wikis-components-files/00-00-00-03-81/Derek-Brodeur-_2D00_-Schematic.pdf">community.element14.com/.../Derek-Brodeur-_2D00_-Schematic.pdf</a></span></td> <td><span style="font-size:80%;">Derek Brodeur - Schematic.pdf</span></td> </tr> </tbody> </table> </div><div style="clear:both;"></div> <div style="font-size: 90%;">Tags: derek_episode, derek_brodeur, plain old telephone, e14presents_derekbrodeur, multi-line, intercom, telephone intercom, telephone, pots intercom, friday_release</div> https://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392/revision/2Wed, 09 Mar 2022 09:29:04 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:a07923ef-18dd-4578-aaea-9f23a5fea710Matthttps://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392#commentsRevision 2 posted to Documents by Matt on 3/9/2022 9:29:04 AM<br /> <div style="background:#ffffff;padding:14px 16px 16px 18px;margin:0;vertical-align:top;border:1px solid #dadada;"><div style="float:left;display:inline-block;padding:0px 25px 8px 0px;"><a href="/challengesprojects/element14-presents/"><img alt="image" src="/e14/assets/legacy/2018/e14PresentsJune818.png" width="180px" /></a></div><div style="display:inline-block;vertical-align:top;width:70%;"><p style="margin:0;"><span style="font-size:12pt;"><strong>Multi-Line Telephone Intercom</strong></span></p><p style="margin:0;"><span><a class="jivecontainerTT-hover-container jive-link-community-small" href="/challengesprojects/element14-presents/">element14 Presents</a></span>&nbsp; <strong>|</strong>&nbsp;&nbsp; <a class="jive-link-wiki-small" href="/challengesprojects/element14-presents/vcp-program/w/documents/4139/vcp-biography-derek">Derek Brodeur&#39;s VCP Profile</a>&nbsp; <strong>|</strong>&nbsp; <a class="jivecontainerTT-hover-container jive-link-community-small" href="/challengesprojects/element14-presents/project-videos/">Project Videos</a></p></div></div><p style="margin:0;padding:0px;">&nbsp;</p><p style="margin:0;padding:0px;">&nbsp;</p><table style="width:80%;display:block;margin:0 auto;"><tbody><tr><td style="padding-bottom:12px;"><span><a href="https://www.youtube.com/watch?v=BGbmFF56iH8">www.youtube.com/watch</a></span></td></tr><tr><td style="text-align:justify;"><p style="margin:0;border:1px solid #b8d7e5;background-color:#e9f6fc;padding:8px;max-width:634px;"><span style="font-family:&#39;Arial&#39;,sans-serif;color:black;">Modern smart phones have become so ubiquitous these days that old analog phones are getting left in the dust. However, you may still have a few of these old phones hanging around your house collecting cobwebs or you may have seen some lingering on the shelves at your local thrift shop. Now’s your chance to put them to good use. In this video, Derek takes you back to a time when stretching a phone cord across the room was the norm by creating a 4-line telephone intercom system with basic ringing capability. The circuit surrounds a DTMF decoder IC which handles keypress detection, a simple AC inverter to handle the ringing and a current source which allows analog communication between multiple phones.</span></p></td></tr></tbody></table><p style="margin:0;padding:0px;">&nbsp;</p><p style="margin:0;padding:0px;">&nbsp;</p><h2><span style="color:#3334ca;">Bill of Materials</span></h2><p style="margin:0;padding:0px;">&nbsp;</p><table border="1" class="jiveBorder mce-item-table" style="border:1px solid #C6C6C6;" width="100%"><thead><tr><th style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;color:#505050;background-color:#f2f2f2;text-align:left;">Product Name</th><th style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;color:#505050;background-color:#f2f2f2;text-align:left;">Manufacturer</th><th style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;color:#505050;background-color:#f2f2f2;text-align:left;">Quantity</th><th style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;color:#505050;background-color:#f2f2f2;text-align:left;"><span><a id="e14-product-link-5034d" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="button" href="https://referral.element14.com/OrderCodeView?fsku=2808967,1106105,2760747,1652293,7940294,NA~5&nsku=44AC2327,60K5115,83X9336,98H0572,13J1639,67K9351~5&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_BUY_KIT" class="e14-embedded e14_shopping-cart-far e14-button" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('5034d'));" data-farnell="2808967~1,1106105~1,2760747~1,1652293~1,7940294~1,NA~5" data-newark="44AC2327~1,60K5115~1,83X9336~1,98H0572~1,13J1639~1,67K9351~5" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Kit</a> </span></th></tr></thead><tbody><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">0.1uF 25v Capacitor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-d3d58" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('d3d58'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1uF 50v Capacitor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-7f27d" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('7f27d'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">20pF Capacitor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-247d7" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('247d7'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2.2uF 250V Capacitor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-8a53d" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=2808967&nsku=44AC2327&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('8a53d'));" data-farnell="2808967~1" data-newark="44AC2327~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1N4001 Diode</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-bcd1c" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('bcd1c'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">IRF540N N-Channel MOSFET</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-294ee" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('294ee'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2N2904 NPN Transistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-437eb" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('437eb'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">HT9170D DTMF Decoder</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">Holtek</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-0d79b" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('0d79b'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">CD4047 Multivibrator</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">Texas Instruments</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-2d464" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=1106105&nsku=60K5115&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('2d464'));" data-farnell="1106105~1" data-newark="60K5115~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">DC/DC Converter 5v / 1A</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">RECOM</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-52517" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=2760747&nsku=83X9336&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('52517'));" data-farnell="2760747~1" data-newark="83X9336~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">LM317T Adjustable Voltage Regulator</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">ON Semiconductor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-9a0a2" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=1652293&nsku=98H0572&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('9a0a2'));" data-farnell="1652293~1" data-newark="98H0572~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">3.579545MHz Crystal</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">ABL</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-3ede0" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=7940294&nsku=13J1639&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('3ede0'));" data-farnell="7940294~1" data-newark="13J1639~1" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">DPDT Relay</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">OMRON</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-e9150" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="https://referral.element14.com/OrderCodeView?fsku=NA~5&nsku=67K9351~5&COM=e14c-noscript&CMP=e14c-noscript&osetc=e14-noscript-tracking-loss" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('e9150'));" data-farnell="NA~5" data-newark="67K9351~5" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">75k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-ec04a" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('ec04a'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">220 Ohm 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-11822" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('11822'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">22 Ohm 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-fd9b7" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('fd9b7'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">56k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-cce99" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('cce99'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">100k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-d210c" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('d210c'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">150k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-455e6" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('455e6'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">68k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-96a70" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('96a70'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-7928d" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('7928d'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">300k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><a id="e14-product-link-5115a" data-at-areainteracted="rte-content" data-at-type="click" data-at-link-type="link" href="javascript:void(0)" data-at-label="PRODUCT_POPUP_OPEN"class="e14-embedded e14_shopping-cart-far e14-link" onclick="event.preventDefault();e14.func.displayProduct(e14.meta.user.country, this, 'embedded-link', e14.func.getProductLinkJSON('5115a'));" data-farnell="" data-newark="" data-comoverride="" data-cmpoverride="" data-cpc="" data-avnetemea="" data-avnetema="" data-avnetasia="" >Buy Now</a> </span></td></tr></tbody></table><p style="margin:0;padding:0px;">&nbsp;</p><p style="margin:0;padding:0px;">&nbsp;</p><h2><span style="color:#3334ca;">Additional Parts:</span></h2><p style="margin:0;padding:0px;">&nbsp;</p><table border="1" class="jiveBorder" style="border:1px solid #000000;width:100%;"><thead><tr><th style="border:1px solid black;border:1px solid #000000;padding:2px;color:#ffffff;background-color:#6690bc;text-align:left;" valign="middle"><strong>Product Name</strong></th><th style="border:1px solid black;border:1px solid #000000;padding:2px;color:#ffffff;background-color:#6690bc;text-align:left;" valign="middle"><strong>Quantity<br /></strong></th></tr></thead><tbody><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">RJ11 Telephone Jack - right angle</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">5</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">120V / 18V Center Tap Transformer</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">1</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">Prototyping PCB</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">2</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">PCB Standoffs + Screws</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">4</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">Metal Enclosure</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">1</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">SOP-20 Breakout board</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">1</td></tr></tbody></table> <div class="migration-injected-attachments"><div style="font-weight:bold;margin:15px 0 5px 0;">Attachments:</div><div></div><table style="border:0;"><tbody><tr><td width="160"><span class="_se_attachment" id="attid_https://www.element14.com/community/api/core/v3/attachments/280953"><a href="https://community.element14.com/cfs-file/__key/communityserver-wikis-components-files/00-00-00-03-81/Derek-Brodeur-_2D00_-Schematic.pdf">community.element14.com/.../Derek-Brodeur-_2D00_-Schematic.pdf</a></span></td><td><span style="font-size:80%;">Derek Brodeur - Schematic.pdf</span></td></tr></tbody></table></div><div style="clear:both;"></div> <div style="font-size: 90%;">Tags: derek_episode, derek_brodeur, plain old telephone, e14presents_derekbrodeur, telephone intercom, pots intercom, friday_release</div> https://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392/revision/1Wed, 12 Jun 2019 20:14:34 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:a07923ef-18dd-4578-aaea-9f23a5fea710rjenahttps://community.element14.com/challenges-projects/element14-presents/project-videos/w/documents/4191/multi-line-telephone-intercom----episode-392#commentsRevision 1 posted to Documents by rjena on 6/12/2019 8:14:34 PM<br /> <div style="background:#ffffff;padding:14px 16px 16px 18px;margin:0;vertical-align:top;border:1px solid #dadada;"><div style="float:left;display:inline-block;padding:0px 25px 8px 0px;"><a href="/challengesprojects/element14-presents/"><img alt="image" src="/e14/assets/legacy/2018/e14PresentsJune818.png" width="180px" /></a></div><div style="display:inline-block;vertical-align:top;width:70%;"><p style="margin:0;"><span style="font-size:12pt;"><strong>Multi-Line Telephone Intercom</strong></span></p><p style="margin:0;"><span><a class="jivecontainerTT-hover-container jive-link-community-small" href="/challengesprojects/element14-presents/">element14 Presents</a></span>&nbsp; <strong>|</strong>&nbsp;&nbsp; <a class="jive-link-wiki-small" href="/challengesprojects/element14-presents/vcp-program/w/documents/4139/vcp-biography-derek">Derek Brodeur&#39;s VCP Profile</a>&nbsp; <strong>|</strong>&nbsp; <a class="jivecontainerTT-hover-container jive-link-community-small" href="/challengesprojects/element14-presents/project-videos/">Project Videos</a></p></div></div><p style="margin:0;padding:0px;">&nbsp;</p><p style="margin:0;padding:0px;">&nbsp;</p><table style="width:80%;display:block;margin:0 auto;"><tbody><tr><td style="padding-bottom:12px;"><span><a href="https://www.youtube.com/watch?v=BGbmFF56iH8">www.youtube.com/watch</a></span></td></tr><tr><td style="text-align:justify;"><p style="margin:0;border:1px solid #b8d7e5;background-color:#e9f6fc;padding:8px;max-width:634px;"><span style="font-family:&#39;Arial&#39;,sans-serif;color:black;">Modern smart phones have become so ubiquitous these days that old analog phones are getting left in the dust. However, you may still have a few of these old phones hanging around your house collecting cobwebs or you may have seen some lingering on the shelves at your local thrift shop. Now’s your chance to put them to good use. In this video, Derek takes you back to a time when stretching a phone cord across the room was the norm by creating a 4-line telephone intercom system with basic ringing capability. The circuit surrounds a DTMF decoder IC which handles keypress detection, a simple AC inverter to handle the ringing and a current source which allows analog communication between multiple phones.</span></p></td></tr></tbody></table><p style="margin:0;padding:0px;">&nbsp;</p><p style="margin:0;padding:0px;">&nbsp;</p><h2><span style="color:#3334ca;">Bill of Materials</span></h2><p style="margin:0;padding:0px;">&nbsp;</p><table border="1" class="jiveBorder mce-item-table" style="border:1px solid #C6C6C6;" width="100%"><thead><tr><th style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;color:#505050;background-color:#f2f2f2;text-align:left;">Product Name</th><th style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;color:#505050;background-color:#f2f2f2;text-align:left;">Manufacturer</th><th style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;color:#505050;background-color:#f2f2f2;text-align:left;">Quantity</th><th style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;color:#505050;background-color:#f2f2f2;text-align:left;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-XYidRO4Y-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=2808967~1,1106105~1,2760747~1,1652293~1,7940294~1,NA~5&amp;nsku=44AC2327~1,60K5115~1,83X9336~1,98H0572~1,13J1639~1,67K9351~5&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=2808967~1,1106105~1,2760747~1,1652293~1,7940294~1,NA~5&amp;nsku=44AC2327~1,60K5115~1,83X9336~1,98H0572~1,13J1639~1,67K9351~5&amp;COM=noscript" target="_blank">Buy Kit</a></span><span class="e14-init-hidden" id="addProduct-XYidRO4Y-unlinked">Buy Kit</span></span></th></tr></thead><tbody><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">0.1uF 25v Capacitor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-qbUmoZMS-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-qbUmoZMS-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1uF 50v Capacitor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-ojAWPhVO-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-ojAWPhVO-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">20pF Capacitor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-TmAA0NVL-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-TmAA0NVL-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2.2uF 250V Capacitor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-PBAabEdf-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=2808967~1&amp;nsku=44AC2327~1&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=2808967~1&amp;nsku=44AC2327~1&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-PBAabEdf-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1N4001 Diode</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-H0qt6yhe-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-H0qt6yhe-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">IRF540N N-Channel MOSFET</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-cyuy8nrP-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-cyuy8nrP-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2N2904 NPN Transistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-kfMefMHo-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-kfMefMHo-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">HT9170D DTMF Decoder</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">Holtek</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-rM0mn3ZH-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-rM0mn3ZH-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">CD4047 Multivibrator</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">Texas Instruments</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-UbvGmxdu-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=1106105~1&amp;nsku=60K5115~1&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=1106105~1&amp;nsku=60K5115~1&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-UbvGmxdu-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">DC/DC Converter 5v / 1A</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">RECOM</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-VFDeea8u-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=2760747~1&amp;nsku=83X9336~1&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=2760747~1&amp;nsku=83X9336~1&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-VFDeea8u-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">LM317T Adjustable Voltage Regulator</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">ON Semiconductor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-3tiwycje-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=1652293~1&amp;nsku=98H0572~1&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=1652293~1&amp;nsku=98H0572~1&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-3tiwycje-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">3.579545MHz Crystal</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">ABL</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-TB0w3oaU-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=7940294~1&amp;nsku=13J1639~1&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=7940294~1&amp;nsku=13J1639~1&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-TB0w3oaU-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">DPDT Relay</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">OMRON</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-V7IsKzYc-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=NA~5&amp;nsku=67K9351~5&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=NA~5&amp;nsku=67K9351~5&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-V7IsKzYc-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">75k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-UjgqIPvt-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-UjgqIPvt-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">220 Ohm 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-QEgthtQw-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-QEgthtQw-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">22 Ohm 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-yoyltQzY-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-yoyltQzY-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">56k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">2</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-adyMY96P-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-adyMY96P-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">100k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-cievx0qV-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-cievx0qV-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">150k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-qi2n1IDS-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-qi2n1IDS-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">68k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-iFF8upN0-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-iFF8upN0-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">5</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-2eCKtilG-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-2eCKtilG-unlinked">Buy Now</span></span></td></tr><tr><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">300k 1/4 Watt Resistor</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"></td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;">1</td><td style="border:1px solid black;border:1px solid #C6C6C6;padding:6px;"><span><span class="e14-init-shown e14-product-link-buynow" id="addProduct-iUG7v9mh-linked" style="white-space:nowrap;"><a class="jive-link-product-addtolist" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank"><span class="pf-widget-map pf-productlink-cart-icon"></span></a><a class="jive-link-product pf-embedded-product-link" href="https://www.element14.com/community/view-product.jspa?fsku=&amp;nsku=&amp;COM=noscript" target="_blank">Buy Now</a></span><span class="e14-init-hidden" id="addProduct-iUG7v9mh-unlinked">Buy Now</span></span></td></tr></tbody></table><p style="margin:0;padding:0px;">&nbsp;</p><p style="margin:0;padding:0px;">&nbsp;</p><h2><span style="color:#3334ca;">Additional Parts:</span></h2><p style="margin:0;padding:0px;">&nbsp;</p><table border="1" class="jiveBorder" style="border:1px solid #000000;width:100%;"><thead><tr><th style="border:1px solid black;border:1px solid #000000;padding:2px;color:#ffffff;background-color:#6690bc;text-align:left;" valign="middle"><strong>Product Name</strong></th><th style="border:1px solid black;border:1px solid #000000;padding:2px;color:#ffffff;background-color:#6690bc;text-align:left;" valign="middle"><strong>Quantity<br /></strong></th></tr></thead><tbody><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">RJ11 Telephone Jack - right angle</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">5</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">120V / 18V Center Tap Transformer</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">1</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">Prototyping PCB</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">2</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">PCB Standoffs + Screws</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">4</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">Metal Enclosure</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">1</td></tr><tr><td style="border:1px solid black;border:1px solid #000000;padding:2px;">SOP-20 Breakout board</td><td style="border:1px solid black;border:1px solid #000000;padding:2px;">1</td></tr></tbody></table> <div class="migration-injected-attachments"><div style="font-weight:bold;margin:15px 0 5px 0;">Attachments:</div><div></div><table style="border:0;"><tbody><tr><td width="160"><span class="_se_attachment" id="attid_https://www.element14.com/community/api/core/v3/attachments/280953"><a href="https://community.element14.com/cfs-file/__key/communityserver-wikis-components-files/00-00-00-03-81/Derek-Brodeur-_2D00_-Schematic.pdf">community.element14.com/.../Derek-Brodeur-_2D00_-Schematic.pdf</a></span></td><td><span style="font-size:80%;">Derek Brodeur - Schematic.pdf</span></td></tr></tbody></table></div><div style="clear:both;"></div> <div style="font-size: 90%;">Tags: derek_episode, derek_brodeur, plain old telephone, e14presents_derekbrodeur, telephone intercom, pots intercom, friday_release</div>