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 ...

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 ...

Most engineers are quite familiar with typical low-power-indicator LEDs, whether they be surface-mount or the classical through-hole packages. All that's needed to use them is a voltage source and a ...

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 ...

VCC has designed a series of LED sockets that feature a built-in current limiting resistor to provide optimal LED performance. VCC has designed a series of LED sockets that feature a built-in current ...

Case-mod newbie here. I've got an HTPC that I recently put together in a Silverstone case with an Asus Z68 Micro-ATX motherboard. When connected to the proper pins, the power LED on the case blinks ...