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Registered Member #1106
Joined: Thu Nov 08 2007, 01:15AM
Location: Seattle, Washington
Posts: 25
So this will be my second coilgun as my first one got boring as it only had 58j of energy in (8) 15v 100,000mfd caps.
Well for my second Coilgun, i am using (8) 350v 3600mfd caps. i was thinking of doing 2 parellel banks of 4 caps in series which will give me 1400v and 7200mfd. a total energy of 705.6j
For my switching, im not going to deal with scr's due to their messyness (IMHO)(mainly the clamping of puck scrs) instead, im just going to look at some "trigger" switches? i dont know what they are called, but its like a spring and you know what i mean.
the charging is the main problem/questions i have on. with 1400vdc going into my caps, im going to need around 1000vac. im having a hard time finding a transformer that will do that for me. any ideas on that??
Registered Member #1320
Joined: Sat Feb 16 2008, 01:31AM
Location:
Posts: 67
that's actually 1764joules and you cap bank will actually be 1400v at 900mf as for switches you best bet is to make you own and microwave oven transformers are the most commonly used transformer for this type if thing (provide about 2kvac).
Registered Member #1106
Joined: Thu Nov 08 2007, 01:15AM
Location: Seattle, Washington
Posts: 25
e=(v^2*c)/2?
e=(1400^2 * .0009)/2? e=882j?
2kvac is alot more than my 1kvac i want. ? wouldn't that blow my caps if i overcharged? which would be easy to happen?
what i was thinking is using this
when i use this, since its 230vac in and 3130vac out, if its 120vac in it should be 1550vac out. ... . . .this 1550vac then turns into 2325vdc, which is still too high to let it charge freely until....soo? what should i do as for charging?
Registered Member #1320
Joined: Sat Feb 16 2008, 01:31AM
Location:
Posts: 67
oops my bad 1400v at 1800mf (no matter how you arrange them same energy ie (350^2*.0036)/2*8=1764) for capacitors in series voltage doubles and capacitance is the inverse of the some of 1/c+1/c...... (ie inverse of 4/3600 is 900mf) times 2 because of parrallel banks is 1800 mf. As for over charging I wouldn't count on it. with 1.7KJ it will take you a good 30seconds at least to charge them. Not quite as instantaneous as your 58J bank. Also you might want to consider investing in a variac, they will allow you to charge you capacitors slowly which is better for the capacitors and easier to stop when you get to the correct voltage. By the way it would take forever to charge you bank off that tiny transformer.
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Second Coilgun, Require Input
