Every once in a while we get a customer inquiry about running voltage multipliers at frequencies of 50-60Hz, which we try to graciously decline, since most of our multipliers are designed to run at 10kHz or higher.
The problem with low frequency multipliers (50Hz – 60Hz) is the slow oscillation at lower frequencies does not charge up the capacitors in the multiplier quickly enough to keep up with normal discharging during the negative cycle.
The reason the voltage multiplier works the way it does is because the capacitors are able to store energy to supply other circuitry down circuit.
Voltage multipliers work best at 10kHz and higher.
Sometimes a D.C. input is used, but in order to generate a high D.C. output voltage, the D.C. input has to be converted to an A.C. signal. This can be done by using a fly-back oscillator or PWM controlling the frequency, and stepping up the signal via a transformer, before being fed into the multiplier.
We normally consider a configuration of this type to be more in line with a power supply, since it incorporates signal conditioning, and a high voltage multiplier.