The humble LM317 adjustable voltage regulator is everywhere ... including driving LEDs and laser diodes. While this circuit may not be as efficient as an LED driver module or a switching solution ...

The circuit he’s building here is a solar charger for the super capacitor. Being a fairly small device there’s not a lot of current, voltage, or energy, but these are different enough from ...

This article explains how to extend the battery lifetime of a device by adding a nanopower converter to an existing system, ...