Open Source Hardware

Open Source Hardwarehttps://community.element14.com/technologies/open-source-hardware/What is the connection between Open Source Hardware and traditional engineering companies. How can professionals & hobbyists learn from each other. What can hardware developers learn from Open Source Software.en-USTelligent Community 12Forum Post: RE: opa1633.lib ?https://community.element14.com/technologies/open-source-hardware/f/forum/56821/opa1633-lib/234828Mon, 06 Apr 2026 08:26:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:6ab7fe2c-e5fa-4ec1-8e4a-f1dbb32be571Andrew JThis post, by shabaz ( ) talks about extracting the Spice model - I guess it was a while ago and his memory is going, bless! KiCad 8: Working with Circuit Simulations! Perhaps you have the file still stored somewhere Shabaz?Forum Post: RE: opa1633.lib ?https://community.element14.com/technologies/open-source-hardware/f/forum/56821/opa1633-lib/234825Mon, 06 Apr 2026 01:05:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:8fed4ec6-6396-497e-9fd9-bb9fa7d92236stanto[quote userid="520842" url="~/technologies/open-source-hardware/f/forum/56821/opa1633-lib/234823"]FYI, I have macs and no windows machines[/quote] You can probably run it with wine .Forum Post: RE: opa1633.lib ?https://community.element14.com/technologies/open-source-hardware/f/forum/56821/opa1633-lib/234824Mon, 06 Apr 2026 00:02:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:85141252-6510-43fb-94f4-0c1b8678ce4dshabazThe .tsc file is a Tina TI format file for a schematic that uses that OPA part. It will have the SPICE model embedded in it. I have not used Tina TI in ages (and don't have it installed currently) so I cannot check if you can export or copy the model from there, but I believe Tina TI is free simulation software to build basic schematics up to a small component limit.Forum Post: RE: opa1633.lib ?https://community.element14.com/technologies/open-source-hardware/f/forum/56821/opa1633-lib/234823Sun, 05 Apr 2026 23:42:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:63752a26-359d-4c4e-9999-940f77f311e3ronydhi yes that's what i have. But there is alot of character symbols which has nothing to do with the spice model contents. I just noticed you say in the instructions " Within the Tina-TI software". FYI, I have macs and no windows machines. Do I need to install Tina-TI to get the proper Spice model file? thankx you for replyingForum Post: RE: opa1633.lib ?https://community.element14.com/technologies/open-source-hardware/f/forum/56821/opa1633-lib/234822Sun, 05 Apr 2026 21:26:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:d116c496-eed8-4335-8b00-821cc69a5c95shabazI don't understand the request; the .tsc file is on their website.Forum Post: opa1633.lib ?https://community.element14.com/technologies/open-source-hardware/f/forum/56821/opa1633-libSun, 05 Apr 2026 20:35:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:af90e50f-0642-44fa-859f-1cbf458df240ronydDoes anyone have the spice simulation model? TI for the opamp does not have the Tina-TI schematic file ( .tsc suffix).<link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=66c45c5a-7feb-4962-8468-60108f6bc752</link><pubDate>Sat, 28 Mar 2026 12:33:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:66c45c5a-7feb-4962-8468-60108f6bc752</guid><dc:creator>michaelkellett</dc:creator><description>I have been playing with the DC coupled pair type of pre-amp. I'm not sure that it gets you any real benefit. This version will work from 6 - 9V, drive the 1k pot load, has about 77dB open loop gain, reduced by feedback here to 45dB. It needed the emitter follower to get good results with that much closed loop gain. C7/R7 deals with a closed loop peak at about 7MHz. PSU rejection is quite good (because of R8, R13, C3 and C6. I cribbed the basic design from the Lustraphone LP100 design by Ian Pullen (1/10/73). Ian designed tuners and amplifiers for Leak in the 60s and I enjoyed working with him for a short while in 73/74. (I don't think he was the primary originator of this ciruit idea.) Ian's version runs from -30V but mine uses a positive supply. MK</description></item><item><title /><link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=38c4e409-3f00-4821-a3dd-8bd7e515ecc9</link><pubDate>Sat, 28 Mar 2026 12:15:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:38c4e409-3f00-4821-a3dd-8bd7e515ecc9</guid><dc:creator>shabaz</dc:creator><description>Oh nice.. glad to hear that the experimentation can be used to try out the millivoltmeter! Is it a HP unit? They were nice, we had one or two at a workplace for audio measurements for radios. I'd made a mistake with the capacitor value! I've fixed it now, and get the same results as you. This is a chance to try out this prototyping board: (+) A Three-Way Prototyping Board for Awkward Through-Hole Components - element14 Community No idea if it will make things easier, but will know soon!</description></item><item><title /><link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=d8b83be6-1856-432d-9d9a-493b39239ede</link><pubDate>Sat, 28 Mar 2026 10:03:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:d8b83be6-1856-432d-9d9a-493b39239ede</guid><dc:creator>michaelkellett</dc:creator><description>I'm glad you liked it. I see that you have trimmed the bandwidth a bit more by changing C1 and C5. I don't much like C5 - I put it in to tame the HF bandwidth (without it the amp has gain at multiple MHz) but it works by lowering the collector impedance and will result in large (possible saturating currents if a large HF signal is applied to the input. I shall have a play with another two transistor circuit (which I've always called a DC coupled pair). It used to be often used in audio magnetic pickup pre-amps where its topology works well with RIAA frequency compensation. I have an excuse for doing this since I just acquired an AC milli-voltmeter and three quite nice attenuators at an auction and I'd like to see them in action. I have a functional 'power' amp design now as well. MK</description></item><item><title /><link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=76848001-1d81-41b5-84ba-924bef27bfa6</link><pubDate>Sat, 28 Mar 2026 00:20:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:76848001-1d81-41b5-84ba-924bef27bfa6</guid><dc:creator>shabaz</dc:creator><description>I simulated in KiCad 10 (quite a tedious process compared to other simulators! the procedure is here: (+) KiCad 8: Working with Circuit Simulations! - element14 Community ) Freq response: If anyone wants to experiment with KiCad, the project folder is here (it includes the simulation workbook). community.element14.com/.../preamp_5F00_simple_5F00_dcr.zip I'll try to solder this up and test for real hopefully on the weekend (but quite a lot of Saturday is not possible unfortunately).</description></item><item><title /><link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=0c807f47-99c7-4557-baf3-7e34376d8737</link><pubDate>Fri, 27 Mar 2026 19:07:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:0c807f47-99c7-4557-baf3-7e34376d8737</guid><dc:creator>shabaz</dc:creator><description>Hi Michael, Thank you for this! I must say, I'm quite disillusioned with the existing circuit, I knew it was supposed to be crude, but it barely functions, especially with that poor PSRR, and the loading means each stage tested in isolation work quite differently when combined. I still need to set up a simulator (new PC, nothing much installed : ( although I might try to replicate your simulation in KiCad, since I've just installed the latest release of that. I think, with two of the stages you describe, that plus a decent power amp would be effective. I will piggy-back a perfboard and prototype the above circuit (and just use an IC amp, I think I have some TDA2822 chips handy, and that can then be replaced with a discrete design later). Thanks again for this design, it's really appreciated.</description></item><item><title /><link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=c6b1dc33-86b1-40a3-b0cf-933b8b235bfc</link><pubDate>Fri, 27 Mar 2026 16:13:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:c6b1dc33-86b1-40a3-b0cf-933b8b235bfc</guid><dc:creator>michaelkellett</dc:creator><description>That's a really weird pre-amp. R16 - R19 set up the DC biasing of Q5 with 3.3 mA of collector current. The AC impedance at the emitter is the impedance of C13//R19, the LF breakpoint is at 0.72Hz - why !!!!!! At higher frequencies the emitter load impedance tends to zero. The AC impedance at the collector is more complex at low frequencies 1k//(180R + ZC12). The LF breakpoint is 19Hz. The input impedance will be very low (because Q5 emitter is effectively grounded for AC). The actual gain will depend on the emitter resistance of Q5 . Since the intention is to drive about 100mV into a 1k load a lower Q5 collector current would be fine. I tried this (in simulation) It has good PSU rejection (18dB worst case at 30 Hz and 90dB at 100kHz. About 2mA current drain. Much smaller capacitors. It's not the best way to use two transistors but not bad. It still uses the first transistor open loop so the gain at 1kHz is lower that you would expect from the ratio of R3 to R4 because of emitter resistance. It manages 28.7 dB of gain (you would expect 33.4) and can drive 1V pk-pk into the 1K load. MK</description></item><item><title>Forum Post: RE: KiCad 10 is almost herehttps://community.element14.com/technologies/open-source-hardware/f/forum/56758/kicad-10-is-almost-here/234609Wed, 25 Mar 2026 17:23:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:e0295e63-c32b-4d60-94ef-4e12c7c3c6e6kmikemooForum Post: RE: KiCad 10 is almost herehttps://community.element14.com/technologies/open-source-hardware/f/forum/56758/kicad-10-is-almost-here/234608Wed, 25 Mar 2026 17:17:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:192a5df3-3fe5-4de2-8c1c-aa896fb71996shabazIt actually can! New feature in KiCad 10.. Selecting Place->Image allows transparent images such as .png format to be dropped into schematics. Can easily move and resize them afterwards too.Forum Post: RE: KiCad 10 is almost herehttps://community.element14.com/technologies/open-source-hardware/f/forum/56758/kicad-10-is-almost-here/234607Wed, 25 Mar 2026 16:28:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:9c83e021-a48d-4047-9255-e170031dcff0beacon_dave[quote userid="123345" url="~/technologies/open-source-hardware/f/forum/56758/kicad-10-is-almost-here/234597"]more coffee colors[/quote] can it do coffee mug rings like in the old days ? ☕Forum Post: RE: KiCad 10 is almost herehttps://community.element14.com/technologies/open-source-hardware/f/forum/56758/kicad-10-is-almost-here/234597Wed, 25 Mar 2026 00:25:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:48f83b89-d5fb-41d8-aa4e-9bc0125a228dshabazHm, this theme is not bad.. more coffee colors : ) It was a ChatGPT attempt. JSON file attached (zipped up). community.element14.com/.../My_5F00_Sch_5F00_Dark_5F00_Theme_5F00_2.zipForum Post: RE: KiCad 10 is almost herehttps://community.element14.com/technologies/open-source-hardware/f/forum/56758/kicad-10-is-almost-here/234596Tue, 24 Mar 2026 23:58:00 GMT93d5dcb4-84c2-446f-b2cb-99731719e767:aa0bd5f3-7a4f-4dc7-aa02-f48e87078b25shabazI finally also installed it... been fiddling around with the color theme for schematics, since I wanted the sheet to be dark themed too. My current color selection still needs a lot of work, but is here, in case anyone wants an example to start. With Windows, the unzipped JSON file goes in a folder called C:\Users\YOUR_USERNAME\AppData\Roaming\kicad\10.0\colors community.element14.com/.../My_5F00_Sch_5F00_Dark_5F00_Theme.zip<link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=62a6c6e6-74b5-4e04-9761-32ba8ea39300</link><pubDate>Tue, 24 Mar 2026 21:35:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:62a6c6e6-74b5-4e04-9761-32ba8ea39300</guid><dc:creator>shabaz</dc:creator><description>Hi DAB, Thanks!</description></item><item><title /><link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=c416897e-3dd3-4419-9fe8-d7425d3825d9</link><pubDate>Tue, 24 Mar 2026 19:40:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:c416897e-3dd3-4419-9fe8-d7425d3825d9</guid><dc:creator>DAB</dc:creator><description>Very good post. Excellent walk through the circuit and the changes you made. Well done.</description></item><item><title /><link>https://community.element14.com/technologies/open-source-hardware/b/blog/posts/simple-dcr-direct-conversion-receiver-part-2-common-emitter-amplifier?CommentId=410a7173-7221-4867-8df0-7148d49ed115</link><pubDate>Tue, 24 Mar 2026 13:39:00 GMT</pubDate><guid isPermaLink="false">93d5dcb4-84c2-446f-b2cb-99731719e767:410a7173-7221-4867-8df0-7148d49ed115</guid><dc:creator>shabaz</dc:creator><description>Hi Jon, That's right, it's for SSB and CW. Thats a clever idea to use PNP for this amplifier stage! I will try to simulate that with some power supply noise at some point once I've reinstalled some things on a new laptop. Apparently a common complaint is that the entire design tends to audibly "buzz", even for those using batteries and I have some theories about that, but need to assemble more of the circuit to find out. Some people for sure may also have unintended coupling causing unwanted feedback, but I also think the output may be pulling the supply rail down very slightly, causing the zener to not regulate the oscillator rail well, which would detune the desired frequency, which would drop the audio output, releasing the load on the supply rail, retuning the oscillator, and then the cycle repeats. It is all a very crude circuit.. all the heavy lifting is done with the mixer, which actually looks pretty good, although I've yet to test it. The rest of the circuitry is quite limited.</description></item></channel></rss>