[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 ...

You’re asking what is LDR? It stands for Light Dependent Resistor or Photoresistor, which is a passive electronic component, basically a resistor which has a resistance that varies depending of the ...

A blast from the Elektor archives: this 1998 battery tester uses a simple LED display to reveal a battery’s true condition under load — even below 1 V.

This is probably the simplest idea to generate flashing light from an LED using AC. The circuit is relatively the simple way of flashing one or more LEDs from a high voltage DC obtained from Mains.