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Switch/Relay Question? Answered

I've been working alot with capacitors recently at a voltage of 330v or so. I've been using this cap bank to discharge into whatever I feel like. Wires (to watch them pop), cds (to "erase" them), etc. Anyway, one problem I've been having is the switches. I flip the switch, it discharges the capacitors and it should work fine. The only problem is the switches are only worth one shot. And I'm using the biggest I can find. (Rated for 15 Amps). I realize that the capacitors are discharging instantly, and the amperage is probably higher then what its rated for, but I expected to get more then one shot out of it. Any suggestions besides a bigger switch?

(I've considered using a series of relays for each capacitor, but that gets expensive.)

Thanks!

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iceng
iceng

Best Answer 9 years ago

The choice of discharge switch a Silicone Controlled Rectifier ( SCR )
and are available in sizes ranging from 240 amps to 600 amps, with a voltage rating of 1,600 volts. 

schematic3.gif
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transistorguy
transistorguy

Answer 9 years ago

This might be exactly what I'm looking for. This looks very promising.

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steveastrouk
steveastrouk

Answer 9 years ago

How do you have a rubber rectifier ?

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iceng
iceng

Answer 9 years ago

I have a couple hokey puck scrs.
Fun thing about them they require a centered force of ten or more pounds anode to cathode to make contact to even test.

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steveastrouk
steveastrouk

Answer 9 years ago

Actually, for a one off, an SCR can switch 1000 of amps.

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Quercus austrina
Quercus austrina

9 years ago

Well, what is the voltage rating of the switch? And is that rating for DC? It might be self-explanatory.

Qa

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transistorguy
transistorguy

Answer 9 years ago

I believe it is around 250 volts DC, but when I charge up the circuit I rarely exceed 300. I felt a 50 volt difference, if that, wouldn't be too much of a problem.

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Vyger
Vyger

9 years ago

What you might need is an old fashioned knife switch. Just Google it and you will see thousands of pictures of them. The regular switches that you have been using are not built for the high current so the contacts either fuse of melt. A knife switch can handle large current flows.