Using this circuit we can catechumen 5V DC from the computer USB anchorage to 12V DC and a circuit like this will acquisition a lot of appliance in USB powered systems. The affection of this circuit is IC LT1618 which is a connected current, connected voltage addition converter. The IC has a advanced ascribe voltage ambit of 1.8 to 18V DC and achievement voltage can be up to 35V DC.
In the circuit resistors R1, R2 sets the achievement voltage. Pin amount 9 is the abeyance pin, beneath than 0.3V to this pin will shut down the IC. Pin amount four is the accepted faculty acclimatize pin. The accepted faculty voltage can be bargain by applying a DC voltage to this pin. If this acclimation is not bare affix this pin to arena and you can omit apparatus R3, R5 and Q1.