Cockroft-Walton Multiplier can output positive or negative voltage

If you’ve already dipped your toes into high-voltage power supply pool you may be thirsty for a bit more knowledge. Here’s a neat illustration of how to build a voltage multiplier that can output a positive or negative supply. It is based on a design known as the Cockroft-Walton Multiplier. It’s the add-on housed in the plastic box seen in the image above. It uses diodes and capacitors in an orientation very common for generating high voltages. In fact, the same thing can be found in that high-voltage bulletin board. The place this differs is when it comes to connecting the multiplier to the PSU.

If you look closely you can see one red and one black banana plug jack poking out the end of the plastic container. There is also a pair of these on the other end. The multiplier has been designed so that reconfiguring the inputs and outputs changes how it works. Each jack has been labeled with one possible input and one output. Choose the desired output (DC+ or DC-) and then follow the labels for the rest of the connections.

What can you do with this setup? Check out the clip after the break that shows it powering a lifter.

11 thoughts on “Cockroft-Walton Multiplier can output positive or negative voltage

  1. How is this ever supposed to reach 250 kV? Those cables and plugs certainly don’t seem up to the task and the air gap is far too small, with some safety margin you need around a meter.

    1. You can have 1MV on a #28 piece of wire if you wanted. The question is how much current is flowing at those voltages. If the current is low enough (which implies you’ve taken precautions against arcing), you can use a hair-sized piece of wire to convey whatever voltage you want.

      1. When I talk about the plugs and wire I mean their insulation is pretty much irrelevant to arcing at 250 kV (it could go straight through the insulation if need be, although it will just escape via the plugs).

        So it all comes down to distance, the usual precaution against arcing for 250 kV in air is a gap of >50 cm … this box doesn’t look large enough to hold off 250 kV from one side to the other.

  2. I have not tried a C/W multiplier, but I have built various designs and sizes of the lifter shown in the video. I happened to score a 75KVDC transformer several years ago via ebay, and run it through a variac to control power. Spearating anode from aluminum foil helps create better ion flow and prevent spark over. The biggest unit I made was a triangle with 6 feet sides. It is still incredible to watch in my opinion…

  3. Can I use a variac transformer which can output 0~260VAC(5A) and then connect a Cockroft Walton Voltage Multipliers which use camera capacitor 104/1KV and 1N4007 as diode.
    I made it series connection about 10 stages,theoretically it can output 10X(input voltage),but I didn’t get that much. Here is my situation:
    Is there anything wrong?Why can’t i get that 10 times voltage?

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