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 ...

This flashlight is just that – a simple switch to turn the LEDs on and off, a button, and from the looks of things, not even a single current limiting resistor. A masterstroke of engineering ...

To calculate the resistance of the series resistor required, we need to look at the current and voltage values recommended by the LED manufacturer. Suppose a manufacturer recommends a maximum ...