Circuit Description

The circuit diagram given here is a simple voltage doubler circuit. In this circuit the central part is the timer IC NE 555. This circuit also includes two transistors Q1 (BC 107) and Q2 (BC 177) as its main part. The actual output current delivered by this circuit is 50 mA and it is suitable only for low current applications. The output voltage of this circuit will be approximately 19V for 12V DC input voltage.

In this circuit, the IC1 NE 555 acts as astable multivibrator operates at a frequency of 9 KHz. The output of this astable multivibrator is connected to the base of the transistors Q1 and Q2. The capacitor C3 is connected in such a way that its negative terminal is shorted to the output of two transistors. When the output of the astable multivibrator becomes low, Q1 will be off and Q2 will be on and capacitor charges. When the output of astable multivibrator goes high, reverse will happen and capacitor again charges to the double of the supply voltage. So the final output across capacitor C4 will be the double of the input voltage.

Circuit Diagram

Voltage Doubler Circuit

Voltage Doubler Circuit


  • Use a Vero board to assemble this circuit.
  • Use a holder to mount IC1.