USB 5V to 12V DC-DC Step-Up Converter circuit
This circuit offers a variety of Buck DC to DC converters. Because as circuit increase voltage as the usb 5v to 12v dc-dc step-up converter. This circuit is called Boost converter circuit.
DC converters
3.7V to 5V Boost/Step-up DC converter circuit using MC34063
Here is 3.7V to 5V boost converter or step up switching circuit using MC34063 and a few parts,1N5819,100uH. For 200mA-300mA of load current.
USB 5V to 1.5V/ 3V Step Down Converter Circuit
See USB 5V to 1.5V/3V Step Down Converter Circuit using LM317. With this, we can use MP3 players (requires only 1.5V AA battery) with USB(5V).
1.5V to 5V boost converter circuit for microcomputer
Small appliances have microcomputer that requires 5V power supply. Why it can use only 1.5V battery? The 1.5V to 5V boost converter circuit inside them.
Step up converter circuit using TDA2822
No light! because of a low voltage battery. How do you increase the voltage up?
You can do many ways.
And, I recommend a simple step-up converter circuit using TDA2822.