0 Voltage Doubler using 555

This is a type of dc-dc converter that doubles the voltage of the source. The circuit is powered by 555 timer IC that operates in astable mode. The output of the timer generates the pulse, and the diode D and capacitor C store the energy and voltage during the first cycle. The total output voltage delivered to the load is equal to the output of the 555 plus the voltage in the capacitor, which is around 2X the source minus drops in diodes .Example is a 6V input can have around 10V to 11V output and 12V input is about 22V output. In short, output voltage is about twice the value of input.

voltage doubler schematic

Part list:
1-555 IC
1-1.2k ohms resistor
1-22k ohms resistor
1-0.01uF capacitor
2-220uF/25V capacitor (C)
2-1N4148 diode (D) or use germanium diode  for better output
6V to 15v battery or dc supply

Note: Limit the output current up to 25mA only for 6V supply and 60mA for 12v supply  to ensure output voltage stability. You can use 555 timer calculator if you decide to change the frequency and values of resistor and capacitor of your timer IC.