[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 ...

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 ...

To measure a zener diode’s breakdown voltage, you need a dc voltage source whose voltage exceeds that of the zener voltage. In Figure 1, resistor R SER provides voltage drop between V IN and V ZEN. In ...

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 ...

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 file type includes high resolution graphics and schematics when applicable. The circuit in Figure 1 uses a bicolor (red/green) LED to indicate the voltage measured with a set of three color ...