Voltage Doubler Arrangements

Thread Starter


Joined Jan 19, 2004
the other day i came across these voltage doubler and tripler arrangements using diodes. unfortunately no explaination was provided for the same on the site.
so i need to know -what is their function?? do they really double voltage?? where are they used


Joined Nov 14, 2003
Are you talking about "bootstrapping?"

Imagine you have a capacitor with one end tied to ground, and the other tied to a voltage source V1. You charge (assuming some finite resistance through the wire) up the capacitor to a voltage V1. The charge stored on the capacitor is Q1 = C*V1. Then you disconnect the ground connection and in it's place you connect it to a voltage source with voltage V2 < V1. Now the capacitor begins to charge up again until the voltage across it is V1, the charge added to the capacitor is C*(V1-V2). Now you disconnect both voltage sources from the capacitor and reconnect the one end of the cap to ground. The voltage across the capacitor is now 2V1-V2, and since V1 > V2, 2V1-V2 > V1. So in essence you have increased your voltage above the original source V1.

Maybe you could post a schematic of the circuit you are talking about?