Cockcroft-Walton voltage multipliers. Here are some applications of the Cockroft-Walton voltage doubler circuit for generating high voltages from a low voltage AC source. The circuit is quite practical for generating thousands of volts (or more) or just a few volts at high current. Since the circuit is AC-coupled it may be connected to a power supply's secondary transformer winding to generate an additional or opposite polarity voltage. 10V IN OUT 9V Capacitors are in series so larger values are needed but a lower breakdown voltage rating is allowed. This connection is recommended when generating high voltages at low currents. 8V 7V IN OUT 6V 5V Capacitors share a common connection but must have a higher voltage rating. This connection is recommended when generating lower voltages at higher currents. 4V TTL Squarewave Input (HCMOS) -4 VDC OUT 3V 2V 1V -9 Volt Output TTL Input AC Input Typical photomultiplier chain. The capacitors may decrease in value at the higher voltages since they do not carry the current for the lower dynodes.