Are you looking for a portable breadboard power supply with a selectable voltage? Also thinking about how long the batteries will last? This project utilizes one or two AA/AAA batteries to generate a preselected voltage of 5V or 3.3V, and squeezes the batteries untill they have almost no power at all. AASaver is based on the Microchip MCP1640 boost converter.
When your electronic devices report that the batteries are ‘dead’ and need to be replaced, do you ever feel frustrated that there is often still a lot of juice in them? Don’t throw away the batteries yet! You can use the remaining energy to do a lot of things, such as powering LED flashlights. This is possible by using a boost converter, which can bump the low battery voltage to a higher voltage, enough to light up LEDs or even power breadboard circuits.