What do you get for the geek who has everything and likes LEDs? A tricked-out LED tester, naturally. [Dave Cook]’s deluxe model sports an LCD screen and two adjustable values: desired current and ...

[mircemk] built a slick-looking LED tester with a couple handy functions built in. Not only can one select a target current to put through an LED, but by providing a target voltage, the system will ...

3V is sufficient to turn on any LED, but is within its reverse break down voltage rating (that is why I did not use the common 9V battery). Short circuit current is approx. 30mA. I used a 3V lithium ...

The simple Diode and LED Tester presented here costs under £5 to build (including all components, the battery and a cheap case) and will indicate the polarity of almost all types of LED and other ...

This circuit can be used to test up to three LEDs at once, connected in series. You can easily increase that number by using a higher supply voltage. If you do so, you should allow 2.7 V for each ...