There are many applications where the accuracy of a digital or analogue (bar graph) is not required but something better than a simple low/high indicator is desirable. A battery charge level indicator ...

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 ...

The following circuit uses a low-power CMOS comparator and an LED to indicate low-battery voltage without causing excessive current drain. To view the application note, click on the URL below. Circuit ...

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 ...

[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 ...