element14 Community
element14 Community
    Register Log In
  • Site
  • Search
  • Log In Register
  • Community Hub
    Community Hub
    • What's New on element14
    • Feedback and Support
    • Benefits of Membership
    • Personal Blogs
    • Members Area
    • Achievement Levels
  • Learn
    Learn
    • Ask an Expert
    • eBooks
    • element14 presents
    • Learning Center
    • Tech Spotlight
    • STEM Academy
    • Webinars, Training and Events
    • Learning Groups
  • Technologies
    Technologies
    • 3D Printing
    • FPGA
    • Industrial Automation
    • Internet of Things
    • Power & Energy
    • Sensors
    • Technology Groups
  • Challenges & Projects
    Challenges & Projects
    • Design Challenges
    • element14 presents Projects
    • Project14
    • Arduino Projects
    • Raspberry Pi Projects
    • Project Groups
  • Products
    Products
    • Arduino
    • Avnet Boards Community
    • Dev Tools
    • Manufacturers
    • Multicomp Pro
    • Product Groups
    • Raspberry Pi
    • RoadTests & Reviews
  • Store
    Store
    • Visit Your Store
    • Choose another store...
      • Europe
      •  Austria (German)
      •  Belgium (Dutch, French)
      •  Bulgaria (Bulgarian)
      •  Czech Republic (Czech)
      •  Denmark (Danish)
      •  Estonia (Estonian)
      •  Finland (Finnish)
      •  France (French)
      •  Germany (German)
      •  Hungary (Hungarian)
      •  Ireland
      •  Israel
      •  Italy (Italian)
      •  Latvia (Latvian)
      •  
      •  Lithuania (Lithuanian)
      •  Netherlands (Dutch)
      •  Norway (Norwegian)
      •  Poland (Polish)
      •  Portugal (Portuguese)
      •  Romania (Romanian)
      •  Russia (Russian)
      •  Slovakia (Slovak)
      •  Slovenia (Slovenian)
      •  Spain (Spanish)
      •  Sweden (Swedish)
      •  Switzerland(German, French)
      •  Turkey (Turkish)
      •  United Kingdom
      • Asia Pacific
      •  Australia
      •  China
      •  Hong Kong
      •  India
      •  Korea (Korean)
      •  Malaysia
      •  New Zealand
      •  Philippines
      •  Singapore
      •  Taiwan
      •  Thailand (Thai)
      • Americas
      •  Brazil (Portuguese)
      •  Canada
      •  Mexico (Spanish)
      •  United States
      Can't find the country/region you're looking for? Visit our export site or find a local distributor.
  • Translate
  • Profile
  • Settings
The Learning Circuit
  • Challenges & Projects
  • element14 presents
  • The Learning Circuit
  • More
  • Cancel
The Learning Circuit
Documents DIY Laser Trip Wire Alarm -- The Learning Circuit 84
  • Documents
  • Files
  • Members
  • Mentions
  • Sub-Groups
  • Tags
  • More
  • Cancel
  • New
The Learning Circuit requires membership for participation - click to join
Actions
  • Share
  • More
  • Cancel
Engagement
  • Author Author: tariq.ahmad
  • Date Created: 30 Dec 2020 2:43 PM Date Created
  • Last Updated Last Updated: 30 Sep 2020 7:24 AM
  • Views 5479 views
  • Likes 9 likes
  • Comments 19 comments
Related
Recommended

DIY Laser Trip Wire Alarm -- The Learning Circuit 84

element14 presents
DIY Laser Trip Wire Alarm

The Learning Circuit | element14 presents |  Project Videos

 

You don't have permission to edit metadata of this video.
Edit media
x
image
Upload Preview
image

 

Now that we know how laser diodes work, it’s time to use one in a project! Karen uses a laser diode and an LDR sensor to create a “trip wire”. When the “wire” is “tripped”, meaning the laser beam is interrupted, lights will flash and an alarm will sound! To create the alarm siren, Karen couples together two 555 timer circuits. The entire project is triggered using a third 555 timer circuit used in bistable mode. And a relay circuit is used to control the motor and LED of the flashing alarm light.

 

Bill of Material:

 

Product NameManufacturerQuantityBuy KitBuy Kit
LM555CN - Timer, Oscillator & Pulse Generator IC, TTL Compatible, Astable, Monostable, 4.5 V to 16 V, DIP-8On Semiconductor3Buy NowBuy Now
LM317T -1.2V to 37V, 1.5A Adjustable Positive Voltage Regulator in TO-220-3 PackageSTM Electronics1Buy NowBuy Now
G5V-1-DC5 -Signal Relay, 5 VDC, SPDT, 1 A, G5V-1 Series, Through Hole, Non LatchingOMRON ELECTRONIC COMPONENTS1Buy NowBuy Now
Ceramic Disc Capacitor, 0.01 µF, 100 V, ± 20%, 5 mmVishay3Buy NowBuy Now
Electrolytic Capacitor, Miniature, 10 µF, 25 V, 515D Series, ± 20%, Radial Leaded, 5 mmVishay3Buy NowBuy Now
Through Hole Resistor, 10 ohm, MF25 Series, 250 mW, ± 1%, Axial Leaded, 250 VMulticomp1Buy NowBuy Now
Through Hole Resistor, 100 ohm, 250 mW, ± 1%, Axial Leaded, 250 VMulticomp1Buy NowBuy Now
Through Hole Resistor, 1 kohm, 500 mW, ± 1%TT ELECTRONICS / WELWYN1Buy NowBuy Now
Through Hole Resistor, 10 kohm, 500 mW, ± 5%, Axial Leaded, 350 VMULTICOMP4Buy NowBuy Now
Through Hole Resistor, 68 kohm, MF25 Series, 250 mW, ± 1%, Axial Leaded, 250 VMulticomp1Buy NowBuy Now
1N4007 -Standard Recovery Diode, 1 kV, 1 A, Single, 1.5 V, 30 AMULTICOMP PRO2Buy NowBuy Now
Trimpot, Single Turn, Cermet, Side Adjust, 220 ohm, Through Hole, 1 TurnsBourns1Buy NowBuy Now
Trimpot, Single Turn, Cermet, Top Adjust, 10 kohm, Through Hole, 1 TurnsBourns1Buy NowBuy Now
Laser diode - 5mW, 650nm, Red - ModuleAdafruit1Buy NowBuy Now
2.5 Inch 5.0W 4 Ohm Full Range Speaker, 66mmVisaton1Buy NowBuy Now
ADVANCED PHOTONIX LDR, Photoresistor, 1 Mohm, 250 mW, 320 VADVANCED PHOTONIX1Buy NowBuy Now
Rocker Switch, SPDT, On-Off-On, PanelZF ELECTRONICS1Buy NowBuy Now
Pushbutton Switch, SPST, Off-(On), Round, RedNTE ELECTRONICS1Buy NowBuy Now
Prototype Board, Phenolic, 30 x 25 grid, 1.6 mm, 94 mm, 71 mmMulticomp1Buy NowBuy Now
BATTERY HOLDER 4 X AA, 6V, w/ switch, wire leadsOSEPP1Buy NowBuy Now

 

Additional Parts:

 

Product Name

Rotating LED Beacon Light

Case materials

Extra Wire

(4) AA Batteries

  • the_learning_circuit
  • laser diode
  • e14presents_karencorbeill
  • e14presents_makerkaren
  • through hole resistor
  • ceramic disc capacitor
  • rocker switch
  • photoresistor
  • Share
  • History
  • More
  • Cancel
  • Sign in to reply

Top Comments

  • makerkaren
    makerkaren over 4 years ago in reply to makerkaren +7
    I draw one of these up for everything I solder. Cause I like planning.
  • kmikemoo
    kmikemoo over 4 years ago +5
    makerkaren I love it. Everything with a 555 in it is awesome! I have a little book like yours and I'm blown away by the number of things created with this simple chip. I really like that you used 555's…
  • makerkaren
    makerkaren over 4 years ago in reply to kmikemoo +5
    Thanks! I feel like a lot of people default to just using an Arduino or other microcontroller and trying to solve all their problems with code. I think there are a lot of applications where that is overkill…
  • beacon_dave
    beacon_dave over 4 years ago in reply to airbornesurfer

    Now that would certainly get you noticed at a 'traffic light' party...

     

    ...although you do run the risk of getting pulled-over for 'impersonating an emergency vehicle' on the way home.

    • Cancel
    • Vote Up +2 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • airbornesurfer
    airbornesurfer over 4 years ago

    Great project, Karen! Now I want to build this into a hat...

    image

    • Cancel
    • Vote Up +3 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • airbornesurfer
    airbornesurfer over 4 years ago in reply to makerkaren

    I think there are a lot of applications where that is overkill

    I just do it 'cos I'm lazy image

    • Cancel
    • Vote Up +2 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • beacon_dave
    beacon_dave over 4 years ago in reply to makerkaren

    "...trying to solve all their problems with code. I think there are a lot of applications where that is overkill..."

    Sounds like a job for a Trollduino ?  image

    https://hackaday.com/2021/01/17/arduino-wannabe-should-have-used-a-555-oh-wait-it-does/

     

    History appears to go around in circles though. When I was starting out in electronics, the ol' timers (people, not 555's, that is) used to claim that the 555 timer was overkill for the task. 30 years on and it's the same argument but between the 555 and the microcontroller or between hardware and software based approaches... image

    • Cancel
    • Vote Up +4 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • jitenshah1950
    jitenshah1950 over 4 years ago

    Thanks.

    • Cancel
    • Vote Up +1 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • makerkaren
    makerkaren over 4 years ago in reply to kmikemoo

    Thanks! I feel like a lot of people default to just using an Arduino or other microcontroller and trying to solve all their problems with code. I think there are a lot of applications where that is overkill so I try to show what can be done with zero programming and simple discrete components. In my mind, it also makes it more accessible since you are just dealing with the electronics side and don't also have to work with code.

    • Cancel
    • Vote Up +5 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • kmikemoo
    kmikemoo over 4 years ago

    makerkaren  I love it.  Everything with a 555 in it is awesome!  I have a little book like yours and I'm blown away by the number of things created with this simple chip.  I really like that you used 555's instead of a microcontroller.  There is elegance in simplicity.

    • Cancel
    • Vote Up +5 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • miles90
    miles90 over 4 years ago

    Hi Karen,

     

    According to the Wikipedia page for the 555 timer, you can build a Schmitt-Trigger inverter gate with a 555 timer. Here is the schematic :

     

    https://upload.wikimedia.org/wikipedia/commons/thumb/3/32/555_Bistabiel_analoog.svg/528px-555_Bistabiel_analoog.svg.png

     

    Here are three books that look interesting. It seems Forest M. Mim’s work is a reference.

     

    https://s12.directupload.net/images/210110/wioqz5j5.jpg

     

    https://s12.directupload.net/images/210110/lhptmw8w.jpg

     

    https://s12.directupload.net/images/210110/dztv8byl.jpg

     

    Have a nice day.

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • makerkaren
    makerkaren over 4 years ago in reply to beacon_dave

    Came here to say this. Like, I’ve done the most videos on 555 timers at this point. So many. But happy to help more if I can. They’re really good at what they do, so I find them very useful for when I want to only use discrete components and not a microcontroller.

    • Cancel
    • Vote Up +3 Vote Down
    • Sign in to reply
    • More
    • Cancel
  • miles90
    miles90 over 4 years ago in reply to beacon_dave

    Yes I did. I learned a lot of things, especially the two comparators story. I will look again to the PWM story. To me this is the most interesting application of the 555 timer.

     

    Thank you.

    • Cancel
    • Vote Up 0 Vote Down
    • Sign in to reply
    • More
    • Cancel
>
element14 Community

element14 is the first online community specifically for engineers. Connect with your peers and get expert answers to your questions.

  • Members
  • Learn
  • Technologies
  • Challenges & Projects
  • Products
  • Store
  • About Us
  • Feedback & Support
  • FAQs
  • Terms of Use
  • Privacy Policy
  • Legal and Copyright Notices
  • Sitemap
  • Cookies

An Avnet Company © 2025 Premier Farnell Limited. All Rights Reserved.

Premier Farnell Ltd, registered in England and Wales (no 00876412), registered office: Farnell House, Forge Lane, Leeds LS12 2NE.

ICP 备案号 10220084.

Follow element14

  • X
  • Facebook
  • linkedin
  • YouTube