Weekend Project: An LED Teter

Discussion in 'FAQs' started by kf4jqd, Feb 4, 2007.

  1. kf4jqd

    kf4jqd Active Member

    Weekend Project: An LED Tester

    I was looking through my latest Walther's sales flyer. I saw in it an LED tester. The cost is $7.49. You can build this alot cheaper or for nothing if you already have the parts.:thumb: Here's what you will need.

    (1) 9v battery connector.
    (1) 500 to 1000 Ohm resistor
    (1) Red alligator clip
    (1) Black alligator clip
    1 inch of red wire
    Heat shrink tubing
    soldering iron or gun
    heat gun

    Lets get started:
    Take the 9v battert clip and solder the resistor to the red wire of the clip. Solder the red wire to othe other end of the resistor. Clip the wires of the resistor short. Then slide the heat shrink tubing over it. Use the heat gun heat and shrink the tubing over the resistor and solder joints. On the other end of the red wire, solder the red alligator clip. Some clips has a screw to tighten up. Then solder the black alligator clip to the back wire. You are now done!

    Coonect a battery to the clip. The gently pull apart the leads on the LED. Connect the LED to the alligator clips. If it doesn't light, reverse the clips. It should now light. If you are testing new LED's. The shortest wire usually gets connected to the black clip.

    This is the simplest project to do. Even a beginner should have no problems. Good luck and let me know if the instructions I gave are easy to follow!


    Attached Files:

  2. YmeBP

    YmeBP Member

    This is awesome!!!
  3. MasonJar

    MasonJar It's not rocket surgery

    That's a great little "how-to". My only feedback is that the picture doesn't appear to match the device described in the text, which may be confusing.

  4. Torpedo

    Torpedo Member

    The unit pictured has a printed circuit board instead of the red wire and terminal posts instead of 'gator clips. The square block is a resistor chip.

    KF4JQD provided a description on how to build something that functions the same as the commercial unit shown. At least, I assume the one pictured is a commercial unit.
  5. kf4jqd

    kf4jqd Active Member

    You are right Torpedo. The unite pictures is sold by Walthers. I don't have one made up. I have a multi meter that has a diode checker in it. You can also use an Ohm meter. I thought this would be a simple project for the beginner to build. I did simple projects like this when I first started my college electronics classes. It introduces you to soldering and basic electronics. Besides it's fun to say to a friend. "I built that!" :thumb:

  6. boppa

    boppa Member

    a tip for indentifying led leads that have been cut off
    the long lead is the anode and goes to the +
    the short lead is the cathode and right next to it(on the round leds anyway) there is a small section of the `rim' around the base that has a small flat section (looks like its been filed away in one spot). This is the neg lead

    another way to tell if you can see inside the led is there are two elements inside that look like they are almost touching. One is smaller and is the anode (+). The other is bigger and is either a triangle shape or an L shape. This is the cathode (-) element

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