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FrozenGate by Avery

BIG capacitor bank






HIMNL9 said:
Maybe you can use a disc thyristor ..... there are some GTO rated 3000A 4500V, also if i don't know the prices :whistle: ..... :p
Click to expand...

yeah I was referring to Grenadiers post using an air powered contactor - I'm already there HIMNL9 - I've got a big disc thyristor / hockey puck SCR on its way to me. Peak power handling is 17000 A :)
 
$30 worth of solid bar got me one bank made, total capacitance is 24,400uF at 700V (5.4kJ!!!). And, I still have 40 something unused caps.

I realized though, I'm going to need something to switch the bank! I don't want to splurge on a puck SCR because I'd probably kill the thing anyway, so I figured a contactor would be the best option.

I have some pneumatics that could slam the thing closed very fast, and that would minimize wear on the makes. Since the caps will discharge there won't be anything to break, so that'll be good. However I need somebody to make me some contacts out of copper, something like this: Mark 5 - Introduction . It's not a hard job, but I don't have the tools to do it. So, who'd be willing to make a few cuts into copper and get a tritium tube in exchange? :-)

Cap pic: http://i.imgur.com/0wdMy.jpg

After a 500V charge, I discharged it via a roofing nail (3.1kJ). HOLY SHIT



...is all I have to say. I'd be willing to charge the 700V bank to 680V (5.7kJ), but I don't think the neighbors would like that. Plus I need more charging current.
 
Do you still need some copper? I think I've got some bits of 1/4" thick oxygen free stuff at work.

I wouldn't be able to shape them, but these scraps are from a piece that we cut a circle out of. A few minutes with a dremel and file and you'd have some nice contacts.
 
I just found a place that sells copper bus bar by the metre. *asks for quote* *prays its not too expensive!*

edit: reasonable - Its a bit dear but I'll have enough of the stuff to make the 10kJ bank, so I'll accept the quote :)
 
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Reasonable meaning...?

New transformer done now. It's 220 turns of 24ga wire on the secondary, with a 16ga 4+4 turn primary, insulated with only the best masking tape I could find.

There was a huge improvement in charging power: half wave rectified it charges the 24800uF 700V bank from 0 to 160V in 5 seconds. If anyone would like to figure out what the power is be my guest, but there will probably be more juice when I full wave rectify it. Hopefully my diodes will get here tomorrow...

http://i.imgur.com/lp8qZ.jpg
 
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I was quoted $60 aud for 5 metres of 25 mmW by 3mm thickness copper bar.

That should be enough to do 4 banks of 10 capacitors.

I like your transformer - very neat - what IS that thing you have the circuit made up on? It looks like a bread board (of the kitchen variety!) I suppose I could do that, but I'm really a neat person when it comes to my electronics, and have spent all this time working on the PCB LOL :) I however cant keep my flat neat to save my life. Hence, no cat :P

I should get my puck SCR in a couple of days, and will order the copper (right here in NSW - factored that in when getting my quote, I dont want to pay an assload of shipping.). Voltmeter and heatsinks for my mosfets should be here soon too :)

and this could be fun - but I dont want to spend $100 on it :P
High Voltage HV Capacitor 70uF 3.5kV laser pulse cap | eBay

Cheers
Ben
 
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Diodes failed and the caps discharged into my new transformer.






...there ain't nothing left of it anymore.
 
I assume the transformer went up spectactularly. Thats a bummer. What voltage and PIV were the diodes rated for?
 
This is what happens when 5kJ discharges into a transformer: http://i.imgur.com/finFJ.jpg

Turns out all the damage was confined to the core, which pretty much exploded. Super glue fixed that up though, and it should work fine until I can find a replacement core from TSC international. http://i.imgur.com/aOwgZ.jpg

The diodes were rated for 4x the expected voltage.
 
So you had like 3Kv diodes on your halfwave. That was impressive that it blew the core apart. Looks like you may need to rewind a new secondary. :P Check it with a meter to be sure before you refit the core - be a tad easier to wind that way ;)

I'm starting to have second thought about building mine now :P
 
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The secondary is ok, as the diodes exploded before the wire did.
At least they went out in a blaze of glory. http://i.imgur.com/skdUN.jpg

While I thought the fun was over for 4th of july, I just found a 30A 1200V ultrafast diode. Time to make some noise! :)
 
Dont you love the smell of exploded silicon in the morning LOL

Nice find re ultrafast diode - now go make some bangs :)

BTW what is that transformer core from / where can I buy one. It'll be much neater than a rewound flyback :)
 
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