Re: Old X ray supply with a *real* transformer
Posted: Sat Jun 08, 2013 5:32 pm
Almost done! Tested at 1kv/10ma. The current sense is only giving me about 1mv/ma, which is no where near as loud as I want - I'll look into that. I didn't want to test it higher till I got it under oil, which it now is.
Sadly, I forgot to put the copper screen between the tubs, so I'll have to pull it out and deal with that at some point soon...come up with a siphon to remove the oil to make the inner tub light enough and so on.
In real use, the oil will be higher level, which I'll probably achieve with the moral equivalent of putting in a couple bricks (in this case, HDPE scrap). But, it works! No reason to believe it won't work well at full power at this point, once the oil finds its way back into the transformer windings - this guy is too nice to fry.
It takes a fat cable to not worry about arcs internally. I used one I got from Cliff S at Spellman, rated for 160kv or thereabouts, as everything else here is overkill, might as well...Since he got me two, I still have the "better" one for the 160kv Spellman power supply that we got ripped off on at ebay, which I have to fully rebuild - the only working parts are the stack and the transformer in that one right now - they shot it here via cannon or something. So here it is with the cable showing - that's 1" diameter insulation, shielded. "The right stuff". I'll add a copper ring to the end so it fits my resistor mounts I have on the back end of my HV FT.
For this one, the ballast is in the supply - it would have been far too dangerous to have a wire out in air with 950+ joules of filter cap directly on it. That's one heck of a bang in the event of an arc, so I put the ballast under the oil with the rest.
Sadly, I forgot to put the copper screen between the tubs, so I'll have to pull it out and deal with that at some point soon...come up with a siphon to remove the oil to make the inner tub light enough and so on.
In real use, the oil will be higher level, which I'll probably achieve with the moral equivalent of putting in a couple bricks (in this case, HDPE scrap). But, it works! No reason to believe it won't work well at full power at this point, once the oil finds its way back into the transformer windings - this guy is too nice to fry.
It takes a fat cable to not worry about arcs internally. I used one I got from Cliff S at Spellman, rated for 160kv or thereabouts, as everything else here is overkill, might as well...Since he got me two, I still have the "better" one for the 160kv Spellman power supply that we got ripped off on at ebay, which I have to fully rebuild - the only working parts are the stack and the transformer in that one right now - they shot it here via cannon or something. So here it is with the cable showing - that's 1" diameter insulation, shielded. "The right stuff". I'll add a copper ring to the end so it fits my resistor mounts I have on the back end of my HV FT.
For this one, the ballast is in the supply - it would have been far too dangerous to have a wire out in air with 950+ joules of filter cap directly on it. That's one heck of a bang in the event of an arc, so I put the ballast under the oil with the rest.