Author Topic: High-voltage power supply (50KV)  (Read 1278 times)

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Offline AutogolazzoJr

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High-voltage power supply (50KV)
« on: November 21, 2017, 11:39:42 am »
I am designing a cheap 50kv power supply. It only needs to supply at maximum 5 watts. Can I use something like this kit: https://www.ebay.com/itm/15KV-High-Voltage-Inverter-Generator-Spark-Arc-Ignition-Coil-Module-DIY-Kit-3-7V/382131734381?epid=564952796&hash=item58f8d3876d:g:aAsAAOSw-89ZRPh7
in conjunctions with a voltage multiplier made with 20kv 10nf capacitors and high voltage diodes? Thanks
 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #1 on: November 21, 2017, 11:14:32 pm »
Wups, wrong thread.
 

Offline floobydust

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Re: High-voltage power supply (50KV)
« Reply #2 on: November 22, 2017, 08:18:46 am »
For under $2 that is a great chinese bargain.
A one-transistor oscillator kit with PCB, switch, flyback, NPN transistor TO-126 (some pics lie and show TO-220 2SD880) and heatsink.

OP where is your thread going?

 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #3 on: November 22, 2017, 09:37:33 am »
Testing x-ray emission from old rectifier tubes. Current limiting resistors will be used. I'll make a proper thread in the right section when this gets started. I just need to know if it will work with a voltage multiplier with capacitors of that value.
 

Offline BU508A

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Re: High-voltage power supply (50KV)
« Reply #4 on: November 22, 2017, 10:18:24 am »
“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #5 on: November 22, 2017, 01:48:24 pm »
Nope, they don't ship to the US.
 

Offline floobydust

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Re: High-voltage power supply (50KV)
« Reply #6 on: November 22, 2017, 04:55:45 pm »
If you are at 40kV or 65kV, is that a problem, to have poor regulation?

I think the hard part will be controlling the output voltage - this runs off 3.7VDC but rated to 12VDC power (with some smoke me thinks). I would be tempted to instead use an IC SMPS/oscillator and measure the output voltage to regulate things, but HV gigaohm resistors are expensive and huge.
Wonder if 15kV is absolute max. this can generate, it seems to be the transformer's insulation limit.

So you could take <10kV and a 6-stage multiplier. Sometimes it's cheaper to use more multiplier stages than the higher voltage rated parts.

The 2CL77 HV rectifier diodes look good, 20kV 5mA 100nsec. and cheap on Ali $0.25 each. 20kV 10nF disc caps are $1.12 ea.
 
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Offline BU508A

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“Chaos is found in greatest abundance wherever order is being sought. It always defeats order, because it is better organized.”            - Terry Pratchett -
 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #8 on: November 23, 2017, 10:36:53 am »
Probably too expensive. Will the kit i linked at the beginning work with a voltage multiplier for low-wattage?
 

Offline floobydust

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Re: High-voltage power supply (50KV)
« Reply #9 on: November 23, 2017, 06:04:24 pm »
Yes, I would say that kit is good to connect to a HV multiplier and make 50kV at a couple watts.

I don't know the operating frequency and the kit has a small transistor and small heatsink so that will limit power output. 5W out (50kV 100uA) might heat it up too much.
 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #10 on: November 24, 2017, 07:23:21 am »
Should be fine, I will use a large heatsink and dunk the entire thing in oil
 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #11 on: February 18, 2018, 10:58:57 am »
Sorry to start up this old post, but I still need help. I fried two of those 15kv kits before i built the 10x cascade, so can't try that out yet.
What i need right now is some way to generate 10 or so watts at 5kv high frequency ac to run into the cascade. What I would really like to get my hands on is an ac flyback and a zvs driver, but I can't find an ac flyback anywhere. Do I have to wind one by hand, or any cheaper way to do it? Will those tiny 15kv ebay kits do?
Thanks
 

Offline ahbushnell

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Re: High-voltage power supply (50KV)
« Reply #12 on: February 18, 2018, 11:07:52 am »
I am designing a cheap 50kv power supply. It only needs to supply at maximum 5 watts. Can I use something like this kit: https://www.ebay.com/itm/15KV-High-Voltage-Inverter-Generator-Spark-Arc-Ignition-Coil-Module-DIY-Kit-3-7V/382131734381?epid=564952796&hash=item58f8d3876d:g:aAsAAOSw-89ZRPh7
in conjunctions with a voltage multiplier made with 20kv 10nf capacitors and high voltage diodes? Thanks

>50 kV with vacuum can make a bunch of Xrays.  I worked on a project at 65 kV and you have to be careful.  I hope you know what you are doing.  Do you have equipment to measure the radiation?  Do you know how to design shielding?

 

Offline IanB

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Re: High-voltage power supply (50KV)
« Reply #13 on: February 18, 2018, 11:19:10 am »
I am designing a cheap 50kv power supply.

I can't help observing the length of the insulators, the size of the bushings, the thickness of the insulation, and the air gap clearances used in 30-60 kV power distribution systems. 50 kV does not like to be confined or contained.

I am inclined to think that any small scale 50 kV generator is also going to be a "self-destroying device". If you try to make 50 kV it is going to destroy the thing that tries to make it.

I fried two of those 15kv kits before i built the 10x cascade, so can't try that out yet.

Case in point. If the 15 kV devices destroy themselves, how can you hope to get up to 50 kV?  :)
I'm not an EE--what am I doing here?
 

Offline ahbushnell

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Re: High-voltage power supply (50KV)
« Reply #14 on: February 18, 2018, 11:25:29 am »
I am designing a cheap 50kv power supply.

I can't help observing the length of the insulators, the size of the bushings, the thickness of the insulation, and the air gap clearances used in 30-60 kV power distribution systems. 50 kV does not like to be confined or contained.

I am inclined to think that any small scale 50 kV generator is also going to be a "self-destroying device". If you try to make 50 kV it is going to destroy the thing that tries to make it.

I fried two of those 15kv kits before i built the 10x cascade, so can't try that out yet.

Case in point. If the 15 kV devices destroy themselves, how can you hope to get up to 50 kV?  :)

That's a good point.  50 kV can be done in air but it takes some care.  (and corona rings). 

A voltage multiplier is probably a good approach. 

 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #15 on: February 18, 2018, 02:30:40 pm »
It's been done before. The 15kv kits fried because of the heatsink was too small. I already have a multiplier but need a zvs driver and ac flyback to complete it. The entire thing will be in oil. Any help please?
 

Offline ikrase

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Re: High-voltage power supply (50KV)
« Reply #16 on: February 18, 2018, 04:26:33 pm »
Of course, there's also the question of a 40kV plus 500 W power supply for cheap. I would be interested whether anybody has any options there.


 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #17 on: February 19, 2018, 01:46:24 am »
Not needed here. All I really need now is an ac flyback. Cheapest way to get one?
 

Offline AutogolazzoJr

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Re: High-voltage power supply (50KV)
« Reply #18 on: February 19, 2018, 08:06:20 am »
 

Offline floobydust

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Re: High-voltage power supply (50KV)
« Reply #19 on: February 19, 2018, 10:13:26 am »
A car ignition coil works fine, they are around 1:85 turns ratio and you don't need many multiplier sections at all.
 


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