EEVblog #469 - Cockcroft-Walton Multiplier
Why Electrical Engineering Stack Exchange recommends it
Electronics Stack Exchange users link it as a clear practical explanation of how Cockcroft-Walton multipliers work, including capacitor choice and the pulsing waveform seen at each stage.
Recommended by 2 people across 2 different months, 2016 to 2020.
What it is
An EEVblog Fundamentals Friday episode in which Dave Jones explains how a Cockcroft-Walton (Villard/Greinacher) multiplier cascade generates high-voltage DC from an AC or pulsed source. He builds and probes a board on camera, showing the waveforms at different stages on a scope.
Cited in 1 Wikipedia article, including Cockcroft–Walton generator.
What people said
Recommends Disgusting · 2018-02 · Electrical Engineering Stack Exchange · on “Voltage Multiplier Frequency and Waveform”
Note: I am aware of this [LINK] question. It is 6 years old and I didn't find an answer there and I didn't want to necro the question. As part of a school physics project I need a very large voltage. I will be generating sparks in a low-pressure environment which will require at least 10kV (we still need to test the jars to see how low a pressure we can realistically maintain). In order to generate the high voltages required I intend to use a Cockroft-Walton Voltage multiplier [LINK] simulate this circuit [LINK] – Schematic created using CircuitLab [LINK] I've seen several values for Capacitors dotted around the internet and no explanation for them. According to this [this video] video its normal
Recommends Andy aka · 2020-05 · Electrical Engineering Stack Exchange · on “Cockcroft walton multiplier output both AC and DC?”
A CW multiplier is used (along with a power oscillator) to step-up a DC voltage from a lower voltage to a higher voltage. It produces DC on its "normal" output but on each stage there will be a pulsing waveform superimposed on the previous stage's DC output. The pulse remains the same amplitude throughout all the stages except for accumulated diode drops and therefore, it has a tendency to become slightly smaller in amplitude as it passes from stage to stage. [LINK] Picture from here [LINK] . can a CW multiplier be used to step up voltage pulses where one would input a lower voltage pulse and get out a higher one? No. Dave has the explanation [this video] .
Cites Andy aka · 2016-08 · Electrical Engineering Stack Exchange · on “Auxiliary swicht-mode-power-supply topology”
Do these circuits have a specific name? Cockcoft Walton voltage multiplier is the name. Here's a multi stage version: - [LINK] Sometimes they are loosely called voltage multipliers but that does give rise to some confusion. Are there any noteworthy trapdoors or design considerations when using this auxiliary output for such applications? E.g. can this introduce a negative impact on the boost stage or overall efficiency? The forward diode voltage drop is the main limiter to efficiency but other than that they can be used for quite high powers (I've designed one for 200 watts) and they can certainly be used for generating HT voltages (50 kV for example in some X-ray machines). Here's [this video] D
Cites Girts · 2020-05 · Electrical Engineering Stack Exchange · on “Cockcroft walton multiplier output both AC and DC?”
I was watching this video [this video] and I noticed that closer to the end he is probing the upper half of the circuit and the scope is displaying square waves , also on the lower side his diagram shows one can take off DC. start about 14 min in the video you can see it on the board. Also a separate question, can a CW multiplier be used to step up voltage pulses where one would input a lower voltage pulse and get out a higher one? Or do the capacitors in the circuit spread out the pulse and flatten its steep rise time?