Voltage Tripler and Quadrupler:
Voltage Tripler an extension of the half wave voltage across each diode is 2Vm as it is for the filter capacitor circuit. It should be obvious from the pattern of the circuit connection how additional diodes and capacitors may be connected so that the output voltage may also be five, six, seven and so on, times the basic peak voltage.
In operation capacitor C1 charges through diode D1 to a peak voltage, V during the positive half cycle of the transformer secondary voltage. Capacitor C2 charges to twice the peak voltage 2Vm developed by the sum of the voltages across capacitor C1 and the transformer, during the negative half cycle of the transformer secondary voltage.
During the positive half cycle, diode D3 conducts and the voltage across capacitor C2 charges capacitor C3 to the same 2Vm peak voltage. On the negative half cycle, diodes D2 and D4 conduct with capacitor C3, charging C4 to 2Vm.
The voltage across capacitor C2 is 2vm, across C1 and C2 it is 3Vm and across C2 and C4 it is 4Vm. If additional section of diodes and from the top of the transformer winding as shown in fig. will provide odd multiples of Vm at the output, whereas measuring from the bottom of the transformer the output voltage will provide even multiples of the peak voltage, Vm.
The transformer rating is only Vm, maximum and each diode in the circuit must be rated aty 2Vm,PIV. If the load is small and the capacitors have little leakage, extremely high dc voltages may be developed by this type of circuit, using many sections to the dc voltage.