While LEDs are common in voltage detection applications, I have never seen an LED circuit that is dedicated to indicating the presence of low values of current flow. This simple LED current sensor ...

Sometimes the most useful hacks are also the simplest ones. A case in point is the LED and resistor assembly that [Skippy] recently posted on his blog. The idea is to solder up some pre-made ...

Windows: Keyboard indicator lights are only useful if you're staring at the keyboard when they turn on. If you're a touch typist, Keyboard Leds puts indicator lights and caps lock warning in the ...

This LED DC voltage indicator circuit is a voltmeter, rather than simply a battery tester. As such it may measure voltages as low as 3V. It utilizes venerable LM741 operational amplifiers applied as ...

In a fashion similar to using stacked Zeners for voltage regulation, this LED circuit cleverly combines voltage reference and voltage indication. Fig 1. This voltage regulator circuit (a) uses green ...