Voltage Multiplier - Arduino Low Voltage LED Driver
Driving an LED from a 5v microcontroller is no problem. Flashing a red, blue, green or yellow LED should be possible even with a microconroller running at 3v but what if you want to drive a white LED that doesn't strart to illuminate until it's voltage gets to about 3.1v?
Worse still what if you are designing a battery operated device and you wanted to squeeze every last second of juice from the battery by allowing the voltage to drop to the minimum the microcontroller will work at? This would be 1.8v in the case of an Arduino chip which is way short of a glowing white LED. The solution is to add a voltage multiplier to the controller output driving the LED. More...