LAST MODIFIED:
A LED test lamp is a very handy device to have. It allows you to test whether a DC voltage exists anywhere in a circuit. It is ideal for automotive trouble shooting where we have 12 volt circuits. Just clip the alligator clip to the body earth and put the probe on to any part you want to determine is live. The LED test lamp has numerous applications.
I've even seen probes of LED test lamps which were needle point so that you could penetrate the insulation of wiring for test purposes.
BTW LED stands for light emitting diode.
The easiest way to house a LED test lamp is to build it into a discarded pen case as depicted in figure 1 below.
Figure 1 - diagram circuit of a led test lamp
To build your LED test lamp you will need:
Personally I'd make the durable hookup wire running to the alligator clip of your LED test lamp about 2' or 600 mm long to give you a bit of flexibility.
Here you are pretty much on your own because it depends entirely upon what you can scavenge or have available. Pen cases are common, I'd try for a transparent one. Wire should surely be capable of being salvaged from discarded consumer equipment. The same might apply to your 560 ohm resistor and the LED.
If you don't know what a 560 ohm resistor colour code looks like, then go to my Resistor Colour Code Page.
Remember, for a new shop bought LED, the anode is the longer lead. For a salvaged one your on your own. If you're not familiar with soldering then here's a page on the topic of soldering.
Copyright Ian C. Purdie © 2000 - 2001 - 2002, all rights reserved. URL - https://www.electronics-tutorials.com/test-equip/led-test-lamp.htm
All material at this site may be used by private individuals for their own non-commercial purposes. Single copies of my pages or files may be distributed to other private individuals at no charge, unless other requirements are noted on the relevant page. However, all material remains the intellectual property of Ian C. Purdie, individual contributors, or other sources who gave permission for use of their material at this site. All copyrights and trade marks are reserved by myself or the respective owners. Material may not be republished without prior written permission, nor may it be mirrored on another server without my prior written permission. Other than as provided in these pages or permissions given, translation into another language other than english and hosting pages in another country is stricly prohibited.
Commercial use prohibited without the prior written permission of www.electronics-tutorials.com
Created 7th March, 2002
Updated 8th March, 2002