Need a BIG 10kv DC supply / High Voltage / Forums

Forums

4hv.org :: Forums :: High Voltage

« Previous topic | Next topic »

Need a BIG 10kv DC supply

previous 1 2 3 4 next

Move Thread

LAN_403

macona

Tue Jun 09 2015, 12:51AM

Registered Member #3272 Joined: Mon Oct 04 2010, 11:40PM
Location: Beaverton, OR
Posts: 101

Thomas W wrote ...

I wouldn't scrap such a lovely transformer! At least try selling it if you arn't gonna use it. Could probably get enough money to get a custom transformer guy to wind you a new one.

Well, if someone is interested in it, $200 plus shipping. Thats what I paid for it. It is either 100kv @ 80ma or 160kv. Not sure which, the seller didn't know. Of course the 80ma is for very short periods, run it at that for an extended period and you will fry the primary.

klugesmith

Tue Jun 09 2015, 04:28AM

Registered Member #2099 Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1714

Hi Jerry.
I bet you can meet your power req. with that BFC and new windings. Am guessing that the original design point (assuming 60 Hz) is about 1.5 volts per turn. One could get proportionally more volts/turn and power at 400 Hz, maybe much higher -- at some point the core loss in laminated steel will become a problem. Experts?

If your transformer theory is rusty, I can help you off-line with computations, and core characterization using test windings & no high voltage. Long ago I reported measuring a similar (but much smaller) XRT, presently still taken apart like yours.

Could put it back together and see what happens when secondary is driven at 60 Hz using 120 volts, or using the output of a NST on a variac. Don't hold your breath.

macona

Sun Aug 02 2015, 02:51AM

Registered Member #3272 Joined: Mon Oct 04 2010, 11:40PM
Location: Beaverton, OR
Posts: 101

Got a transformer, a guy had a couple e-beam power supply chassis that were partially parted out and still had the transformers, HV bridges, and a lot of other goodies I can reuse to build my power supply. The transformer is overkill, the power supply was rated to do 10kv at 1.4amps. And heavy... After I unloaded it from my pickup I found a site selling one and said it is 305lbs. So I have two of these transformers now. The second might make a good bug zapper.

I have a 3hp vfd I am going to hook up to it and see how it reacts.

Airco Temescal CV-14 transformer by Jerry Biehler, on Flickr

Hazmatt_(The Underdog)

Sun Aug 02 2015, 04:25AM

Registered Member #135 Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735

Just remember, at these kind of power levels, you should not be doing this alone for any kind of test.
Also, if you do have an accident, someone will probably get killed, so safety and communication are extremely critical.

Electra

Sun Aug 02 2015, 08:17PM

Registered Member #816 Joined: Sun Jun 03 2007, 07:29PM
Location:
Posts: 156

If I am correct I think it may be possible (if you have the same voltage windings as your supply), to use just 2 windings in parallel if you have only single phase mains. You need to have them phased the right way round, So you may need to access both ends of each primary and secondary windings. And as you'd expect you can only use it at 2/3 of its original VA if you want to keep within its limits. Though if its already larger than you need..

Using a 3 phase drive might allow you to vary the power at the same time, so might be a good idea after. It'll result in lower ripple on the output, as 3 phase rectified full wave doesn't fall to 0v on each cycle.

macona

Mon Aug 03 2015, 03:20AM

Registered Member #3272 Joined: Mon Oct 04 2010, 11:40PM
Location: Beaverton, OR
Posts: 101

Yes, the primary side of the transformer is wired delta and the output is setup for wye but they can be rewired. Running it off a VFD would be nice because I would need less filtering on the output and I can probably do voltage regulation using the vfd. I think there should be enough iron in the transformer to smooth the pwm out.

Daedronus

Mon Aug 03 2015, 10:05AM

Registered Member #2329 Joined: Tue Sept 01 2009, 08:25AM
Location:
Posts: 370

any reasons not to use tungsten boats? If contamination is a issue, there are also alumina coated tungsten boats...

macona

Tue Aug 04 2015, 07:21AM

Registered Member #3272 Joined: Mon Oct 04 2010, 11:40PM
Location: Beaverton, OR
Posts: 101

I have a second system for doing thermal evap. There are just certain materials that don't do well with thermal.

Veeco 770 vacuum coater by Jerry Biehler, on Flickr

The system with the e-beam will eventually get a couple sputter guns as well.

radiotech

Wed Aug 05 2015, 05:59PM

Registered Member #2463 Joined: Wed Nov 11 2009, 03:49AM
Location:
Posts: 1546

If you are going to power that core with a VFD, be concerned with the transients
that those drives produce. They are used with motors, which essentially have a
short circuited secondary. This limits winding impedance. The transformer does not
have that, unless you load the secondary.

Also the carrier howl, may rattle the old insulation.

macona

Fri Aug 07 2015, 06:28AM

Registered Member #3272 Joined: Mon Oct 04 2010, 11:40PM
Location: Beaverton, OR
Posts: 101

I know a guy who designs VFDs and he thinks it will be fine. Here's hoping! The windings should be OK, each winding section is epoxy impregnated.

Otherwise I will be rewiring the primaries to run in parallel and have to add a whole bunch of bulk capacitance.

I got the thing mostly re-wired. I dont have the 3CW-20000A7 tube or even a smaller 3CX-10000A7 so I am going to have to come up with a different voltage regulator. Thinking of trying to stack a bunch of mosfets. I have a w whole bunch of APT24M120L 24A, 1200v mosfets

to mess with. Capacitively couple the gate and cross my fingers. I have about 50lbs to play with:

Tub-o-mosfets by Jerry Biehler, on Flickr

previous 1 2 3 4 next

Moderator(s): Chris Russell, Noelle, Alex, Tesladownunder, Dave Marshall, Dave Billington, Bjørn, Steve Conner, Wolfram, Kizmo, Mads Barnkob