Development of HV smps

This forum is for specialized infomation important to the construction and safe operation of the high voltage electrical supplies and related circuitry needed for fusor operation.
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Posts: 1
Joined: Wed Jan 08, 2020 12:24 pm
Real name: HynaStetina

Development of HV smps

Post by HynaStetina » Thu Jan 16, 2020 9:31 am

I'm working on project which is not relatet to fusors, but it require negative 30~60kV DC/2kW smps. Spellman gave me an offer for 15000 USD without VAT (supply has two aditional floatining units for filament). Other companies are cheaper, but still outside of my budget since it´s my personal project.

So i decided to build my own smps.
My key requiremenrs are:
- stable DC asmuch as possible with minimal ripple
- capable of working 24/7 at full power
- future CE/UL/S2 certifications in mind

Since the development process is starting to get really expensive, im looking for ways how to get some fundings.
So my question is if i make a more basic version of my smps, is there any interest from your side?
By basic version i mean for example without PFC, lower output power, no floating supply for filament, no casing, etc.

It will be still expensive since there are SiC and GaN transistors, reliable HV diodes, optocouplers... only ferrite core cost me in current configuration 150 USD.

What is your opinion?

Cai Arcos
Posts: 132
Joined: Fri Oct 12, 2018 1:30 pm
Real name: Cai Arcos
Location: Barcelona, Spain.

Re: Development of HV smps

Post by Cai Arcos » Thu Jan 16, 2020 4:58 pm

At least for me, buying it simply takes away the fun of it (although HV PSUs are way more interesting to me than the fusor, so that might not be shared by more here).

I'm aware that flybacks, even those from old TVs, are not able to supply the required current. Have you tried however to measure the permeability/saturation point of the ferrite core of such transformers (I'm talking of the old Black and White TVs)? It seems to me that the area holding you back most are magnetics.

They are inexpensively available in eBay. I will buy one soon to do some testing, after 4 months trying to find an old vacuum tube TV in used stores/dumpsters.

This post [/url]viewtopic.php?f=11&t=11985[/url] contains useful discussion, as well as mentioning ways to obtain cheap ferrite cores (through China or asking samples).

Also, might be looking for the multiplier board of Spellman supplies (discussed extensively in this forum also) could be a useful shortcut.


Rex Allers
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Joined: Sun Dec 30, 2012 8:39 am
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Location: San Jose CA

Re: Development of HV smps

Post by Rex Allers » Thu Jan 16, 2020 9:00 pm

Unfortunately Silviu seems to be one of the members who lost all of their attachments. So the post about a power supply design project, that Cai provided a link to, is missing all of the pictures of the work that Silviu posted.
Rex Allers

Rex Allers
Posts: 437
Joined: Sun Dec 30, 2012 8:39 am
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Location: San Jose CA

Re: Development of HV smps

Post by Rex Allers » Thu Jan 16, 2020 9:09 pm


You have not followed the rules for a new member. Please fix your username and make a post in "please Introduce yourself".

(Posting my new-user reply again.)

When you registered you clicked to accepted the terms that were given on the 1st registration page:
Fusor Forums - Registration

That page contains the same rules as what is listed here:
Board index - Announcements - Announcements and Site Administration Topics
Fusor.Net Policies and Procedures ... 508#p69690

and specifically The Rules: #1
The forum rules require you to use your full name as your username. If your name is John Smith, your UserID (i.e. login handle) must be John Smith, or John_Smith. This is the name that will appear in the forum listings. “JSmith” or “JohnS” or “JS997” or “handles” like “MrFusion” or “ProtonBoy” are NOT permitted.

Also there is: The Rules: #2
New members are required to introduce themselves in the "Please Introduce Yourself" forum prior to posting elsewhere on the site.

You have not complied. Please change your username to comply.

Changing your Username

Here's how:
  • Login to the board
  • click your current username in the upper-right of the main page and select User Control Panel from the pull-down
  • In the tabs at the top, select Profile
  • At the left column, select Edit account settings
  • Edit the Username: field to be your full name
  • Type your password in the Current password: field (near bottom of page)
  • Click Submit button at bottom
  • Note: After you change Username, the new name becomes what you use to login to the Forum. Your password should remain the same.
I also suggest adding a Location to your profile. It can help to know generally where a member is in the world to adjust a response to them. I have used my City and State, but if you are worried it could be more general -- just State, something like Central USA, just your Country is better than nothing.

Adding a Location
(Skip the first 3 steps if you are already in the Profile section from doing the Username update.)
  • Login to the board
  • click User Control Panel near the top of the main page
  • In the tabs at the top, select Profile
  • At the left column, select Edit profile
  • Edit the Location: field
  • Click Submit button at bottom
This Location information will appear in the right column, under your name, when you post.

Don't forget to make your "Please Introduce Yourself" post too.
Rex Allers

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