High Voltage Power Supply for Marx Generator




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Some of you are asking me to post an instructable about how to make an high voltage power supply to power the Marx Generator on this instructable.
Well, here is the instructable you have been waiting for!

The device we are going to use to make a power supply for the Marx Generator is called Cockroft-Walton Voltage Multiplier, now that is a lot of words, so what most other people call it is what we are going to call it, the Voltage Multiplier.

This one is a different design from the one I used for my Marx Generator, I was going to post the other design, however, it was quite difficult to build, so I came up with this new design.

The new design has more advantaged over the old design, I will explain them:
  • Easy to build
  • More efficient
However, the new design has one disadvantage, it requires mains electricity, but that is not very much a problem, we can just add fuse (and safety resistors if you want). At least it is easier to build!

Disclaimer: This project is very dangerous to operate, it generates high voltages (6000 volts). Please do not attempt to build this voltage multiplier unless you are familiar with high voltage. I am NOT responsible what ever happens to you and others with this voltage multiplier.

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Step 1: Get the Things!!

Depending where you live, get the things that will be suitable to your mains power..

If your country uses 110v or 120v, get the things as listed:
  • 34 1N4007 diodes
  • 34 100nF film 200v (or greater) capacitors
  • 100mA fuse

If your country uses 220v or 240v, get the things as listed:
  • 18 1N4007 diodes
  • 18 100nF film 400v (or greater) capacitors
  • 100mA fuse

The X2 capacitors will also work well, that is what I used for this voltage multiplier.

I got the diodes and the fuse from Farnell. I got the capacitors from Maplin, however, the capacitors are no longer stocked at Maplin, But you can still get it from Farnell. Here is a list of things you will need to get if you are going to buy the components from Farnell.
1N4007 diodes
100nF film 400v capacitor
100nF film 200v capacitor
100mA fuse

Step 2: Schematics

Here are the schematics, it is really easy to make, however, you need to make 34 stages of capacitors and diodes if you live in 110v or 120v area, or 18 stages for 220v or 240v area, NOT 6 stages like you see in the schematic, I cannot add more stages to the schematic, sorry...

The schematic also includes the recommend value of the safety resistors, you don't have to add those resistors, it just makes everything safer.

Step 3: Start Making the Multiplier!

I don't know how I can explain how to make this, but I will try my best.

First, glue the capacitors together to make solder a whole lot easier, Or you can use a vise if you have one, that will also help you to get the job done faster.

As you can see in the picture, I glued seven capacitors together, and I am going to glue some more on when I solder seven diodes on the multiplier. Doing so makes your job easier...

Step 4: Solder on the Diodes...

Then start soldering on the diodes onto the capacitors like you see in the schematic. And trim off the excess leads as you go along.

Also, make sure you make nice, shiny, and round(ish) solder joints to avoid corona discharge which can cause a lot of problems to your voltage multiplier.

Step 5: Completed, and Check Your Connections...

After you had soldered all the diodes onto the capacitors, check your connections closely:
  • Are all the diodes facing in one direction? If not, change the polarity of the diode.
  • Are all the solder joints shiny and round(ish)? If not, fix that.

Step 6: And the Final Connections

And finally, solder on the fuse, (safety resistor,) and the wires. It might be a good idea to cover all of that in hot glue, to prevent the wires breaking and causing a huge problem.

Step 7: Completed!

Well, there you go, a high voltage power supply for the Marx Generator!

Also, it is high recommended you to put this whole voltage multiplier in a project box and fill it with molten paraffin (candle wax). You can easily buy paraffin from most hobby stores.
The reasons for doing this are:
  • Protects you and others from high voltage electrical shock. (That is the main reason.)
  • Prevents corona discharge
  • And of course, it make everything look better and safer!

Step 8: Sparks and Stuff

Best luck to you for making a Marx Generator and the high voltage power supply!

You don't have to use the voltage multiplier just only for the Marx Generator, you can use it as a high voltage power supply for some thing else, like kirlian photography, static motor, and stuff like that. Or you can use it just for fun like make sparks jump between the ends of the wires, and impress your friends with it too! Like I did below on the pictures! :-)

If you want more voltage from the voltage multiplier, just simply add more stages of capacitors and diodes! Each stage will add on another 120v or 240v to the voltage multiplier.

Well, I hoped you enjoyed this instructable!
If you have any questions, or need help, or found an error, or anything, make a comment! I like comments! :)

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296 Discussions


1 year ago on Step 3

I built a 200kv marx generator. The caps were expensive off ebay. Had to buy high voltage resistors aswell, not a cheap project.works great though. Will post a video on youtube. I used nst for psu. Very dangerous output, possibly lethal and very loud. I used surge arresters instead of spark gaps


2 years ago

Hello, I accidentally bought a 100 volts 100uF for this, will it still work if that's the case?


Hello, I built this power supply for my marx generator, but it only sparked every thirty seconds. On adding another stage {two capacitors} it sparked every twenty or so seconds, over a spark gap of a couple of millimeters. I then added two capacitors rated for 4KV, and it sparked every twenty seconds, with much brighter sparks. I connected it to my marx generator and my marx generator sparked every four or five seconds over a maximum spark gap of about half a centimeter to one centimeter. The voltage is onvuiously not enough. Could someone please tell me how to make this multiplier spark more frequently? Thank you.


2 years ago

Great Project,

Can you please tell me my output based on following input (I tried the calculator you sent but it blows my mind..)

If I use 10uF Capacitors (100) with 1A current and 3.7 volt DC input, will I be able to generate something near your output. Kindly help.

If not, in that case, how many should I use?

Actually, I want to connect a PAM 8403 (Audio amplifier)'s output to it's input and then use this output to go in my tesla coil (trying to make a musical tesla). I hope it works, that's why kindly help me..

Awesome tutorial.

3 replies

Reply 2 years ago

Thank you for your reply. But can you explain in detail please..

I did as mentioned in your tutorial for 220 volts supply. After first spark, it used to burn down, I even tried connecting a resistor in input supply. But after the first spark generates, the second spark becomes less visible and later on it stops being visible. Making me to think that I have done something wrong with the connections. But I have not..

I need your wise suggestions and help..
With Regards..

Im having a problem. When I turn this thing on it raises only to 300 VDC, not only that, on every capacitator its the same voltage.. What could be causing the problem? I have 18 stages and it's all the same.

4 replies

I have the same problem, but today I figured that the frequency that I am using is to low. I am using the standard 50 Hz 230V from the socket (with a split transformer, for safety). I also get the same voltage at every stage, so I tried it with a signal generator and when I give 5 kHz works OK. I think in my case I will use bigger caps, as suggested in this instructable (currently using 1nF). I will report back when I try it out.


Reply 3 years ago

SashaM3 How am i suppose to give 5khz from Signal generator as i am already giving AC230 supply??? do i need to connect it seperatly with it??? or need anything else?

Keerthan ks

3 years ago

Can u plz say which capaciter did u use

saket bishnoi

3 years ago

Please give me more information about diodes you used . there are many of them with different ratings in 1N 4007 type . Tell me which one to use . Reply ASAP.


3 years ago

can i just add more stages or do i need to get different capacitors or diodes?


3 years ago

I cant find 100mA fuse... What if i use 500mA fuse???


guys am from India i had a doubt that shall i connect this directly to 230v ac or want to step down it? please say me because i made it but it doesn't give output

1 reply

My multiplier works through six stages and will get me close to 950 VDC, but after that the voltage begins to drop. By stage 30, I am only getting around 700 VDC. What could be causing this?


4 years ago on Introduction

One way to potentially simplify this is to use a step-up transformer first; that way you won't need so many stages.