Enter any two of the three values into the calculator to determine the missing value for an ideal (no-load) Cockcroft-Walton multiplier. For best results, use the peak input voltage.

Cockcroft-Walton Multiplier Calculator

Enter any 2 values to calculate the missing variable

If your source is a sine wave specified in RMS, convert to peak: Vp = √2 · Vrms.

Cockcroft-Walton Multiplier Formula

The following formula is commonly used as an ideal, no-load approximation for the output voltage of a Cockcroft-Walton multiplier (ignoring diode drops and voltage sag/ripple under load).

V_{out} \approx 2 \cdot n \cdot V_{in}

Variables:

  • Vout is the (ideal, no-load) output voltage (V)
  • n is the number of stages
  • Vin is the peak input voltage, Vp (V)

To estimate the ideal output voltage, multiply the peak input voltage by two times the number of stages. If your input is specified as sine-wave RMS, convert first using Vp = √2 · Vrms.

What is a Cockcroft-Walton Multiplier?

A Cockcroft-Walton multiplier is a type of voltage multiplier circuit that converts an AC (alternating) input waveform into a higher-voltage DC output. It is composed of a network of capacitors and diodes that are connected in a ladder-like configuration to generate high voltages. This type of multiplier is used in applications where high voltage but low current is required, such as in (historically) CRT television sets, particle accelerators, and x-ray machines.

How to Calculate Output Voltage in a Cockcroft-Walton Multiplier?

The following steps outline how to calculate the ideal (no-load) output voltage in a Cockcroft-Walton multiplier.

  1. First, determine the peak input voltage (Vin = Vp) in volts. (If you have Vrms for a sine wave, compute Vp = √2 · Vrms.)
  2. Next, determine the number of stages (n) in the multiplier.
  3. Next, gather the formula from above Vout ≈ 2 · n · Vin.
  4. Finally, calculate the output voltage (Vout) in volts.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

input voltage (Vin) = 10 V (peak)

number of stages (n) = 4

Vout ≈ 2 · 4 · 10 V = 80 V (ideal, no-load).