Usable transformer

For Short Term Learning Discussions ONLY. This area is for CURSORY questions and connecting with other users ONLY. ALL technical contributions need to be made in the appropriate forums and NOT HERE. All posts are temporary and will be deleted within weeks or months. You should have already search the extensive FAQs in each of the forums before posting here as your question may already be answered.
Ryan Copeland
Posts: 15
Joined: Fri May 18, 2018 1:47 am
Real name: Ryan Copeland

Usable transformer

Post by Ryan Copeland » Mon May 21, 2018 7:44 pm

Hi, I'm Ryan Copeland and am in the process of building a fusor. I found a relatively cheap power supply on eBay. The specifications are: +/-40KV 400W up to 12mA. I was wondering if this transformer would be adequate to achieve and somewhat easily detect resulting neutrons.
Thank you for the help!

Ameen Aydan
Posts: 37
Joined: Sun Apr 15, 2018 7:33 pm
Real name: Ameen Aydan

Re: Usable transformer

Post by Ameen Aydan » Mon May 21, 2018 8:13 pm

just looking at this post, it seems like a lot of people are going to come to here to shame you. Why? because this has been covered in the FAQs. Do a little searching and you'll find it. And don't worry, it happens to a lot of new people on this forum. To answer your question, yes you can use this as it is more than enough. But you have to make sure you have the right amount of X-ray protection as it could get a little nasty with 40Kv. Also, make sure that it is a negative polarity supply.

Ameen

Ryan Copeland
Posts: 15
Joined: Fri May 18, 2018 1:47 am
Real name: Ryan Copeland

Re: Usable transformer

Post by Ryan Copeland » Mon May 21, 2018 9:58 pm

Thank you for directing me Ameen. I have already researched this topic and have found several posts about the 500 Watt threshold but I was wondering if this supply would make the cut (since it is only 400W). I was also concerned about how to wire this specific transformer. I'll try to insert the link.
https://rover.ebay.com/rover/0/0/0?mpre ... 2927214746

User avatar
Richard Hull
Site Admin
Posts: 10902
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: Usable transformer

Post by Richard Hull » Mon May 21, 2018 10:44 pm

Someone with $76.00 to blow should buy one and see if the specs are a hopeful dream that is really a joke. I wonder just how adjustable these are. The rather rotten spec sheets look as if there is a short range of adjustment and they come on a 5kv and go from there. I assume this level is where the switcher first kicks in. The dual flybacks look like they grant the ground free isolation needed for plus or minus operation. What happens if you demand over the 10ma shown in the specs???

Time will tell if these are a godsend or failed dream. I would say buy it for sure and report back...It's not my $76.00.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

Ryan Copeland
Posts: 15
Joined: Fri May 18, 2018 1:47 am
Real name: Ryan Copeland

Re: Usable transformer

Post by Ryan Copeland » Mon May 21, 2018 10:53 pm

I have one on the way and will experiment with it throughout its range and report back.

Rex Allers
Posts: 236
Joined: Sun Dec 30, 2012 8:39 am
Real name:
Location: San Jose CA

Re: Usable transformer

Post by Rex Allers » Tue May 22, 2018 1:35 am

If you already ordered I hope you bought the model you really wanted.

The $76 version seems to be 10kV 50W. Looks like CX400A is the 40kV 400W that might be worth trying but that is $152.
None of these seem to be for 110VAC input, they need around twice that.

These are not completely untested here. Not sure if I could have found this with a search on the forum if I didn't know it was there, but:
Test of Chinese Precipitator Supply
by Finn Hammer » Tue Nov 14, 2017 3:07 am
viewtopic.php?f=11&t=11992&p=78208&hilit=finn#p77912

The model he tested seems a 30kV 200W but looks similar. Board in his picture looks very much like this one from the current ebay listing.
40k wimpy.jpeg
In that picture it looks to me like the two HV transformers are connected in series. Maybe that's how they get to 40kV? I hope the insulation in the device is really up to doing that if I am right. Listing is rather confusing. No idea if that pic is of the 40kV 400W.

As Richard, I also wonder if it is really able to do 40kV at 10mA for a while. Finn's testing seemed to indicate the one he tried could probably make rated power, but load was not a fusor plasma.
Rex Allers

Ryan Copeland
Posts: 15
Joined: Fri May 18, 2018 1:47 am
Real name: Ryan Copeland

Re: Usable transformer

Post by Ryan Copeland » Tue May 22, 2018 1:53 am

I have seen the post and figured this would be better than nothing, especially for the price, so I purchased the CX-400A model, which is the +/-40KV 400W transformer, it costs more but isn't 100W (like the $76).

User avatar
Richard Hull
Site Admin
Posts: 10902
Joined: Fri Jun 15, 2001 1:44 pm
Real name: Richard Hull

Re: Usable transformer

Post by Richard Hull » Tue May 22, 2018 3:49 am

Nice memory and catch Rex. good luck on getting the supply to work. Finn noted the circuit shut down at overload. Sounds like what the pro-supplies do when operated in the normal mode. Again, good luck.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.

prestonbarrows
Posts: 211
Joined: Sun Jun 24, 2012 5:27 am
Real name:

Re: Usable transformer

Post by prestonbarrows » Tue May 22, 2018 4:06 am

In general, flyback topologies are not the best for plasma applications. Especially poorly regulated chineesium perfboards.

These are barebones and stripped down for cost. At best you can hit their ratings into a stable resistive load. Or at best a CRT or flouro bulb. Beware how they react with the dynamic open and shorted loads of a fusor style plasma.

My bet is you can coax an intermittant glow discharge out of this but not a well controlled fusion producing system.

ian_krase
Posts: 453
Joined: Mon Nov 28, 2016 7:48 am
Real name: Ian Krase

Re: Usable transformer

Post by ian_krase » Tue May 22, 2018 7:29 am

Or a beam on target!

Post Reply