In some electronic circuits we need a 9 volts power supply , but we need to use a battery if that device is mobile . In many cases we don’t have a 9 volts battery or we don’t have enough space to put a 9 volts battery inside the device , so this case we can use a this inverter circuit that will convert 1.5v to 9v to take the place of those expensive 9v batteries.

The input voltage for this inverter can be from 1.5 volts , up to 4.5 volts .  When no current is being drawn from the output the current is less than 10mA.

This inverter circuit is very simple requiring few components , but it can be used only for projects that require low current .  The L1 coil must have 60 turns on a 10 mm ferrite slug 15 mm long , using a 0.25 mm diameter enameled wire .