300 Amps switch

MOSFET?

Half of this:

IGBT can handle 300 A current. Maybe a high power transistor will also work.

Mike

Open is hard; how about interrupt for a few milliseconds? If you connect that capacitor and the arc in series with a transformer secondary, a few hundred volts on the primary will drop the arc voltage and keep the current in check.

A couple hundred volts and ten amps is easier to handle than tens of volts and a hundred amps.

:Hi, : :I want to develop a welding system based on a high power capacitor, 24 :V, 1 F. : :To do so, I need some kind of switch to open the circuit once the arc :is formed and lots of amps are flowing through it. : :Any advise ? : :thanks in advance.

This problem applies to wire feed arc welders in general and has perplexed the minds of welder manufacturers such as Lincoln. Here is an electro-mechanical contactor type designed by Lincoln in a patent from 2008.

And a more complex solid state design from another designer in 2006.

At this low of voltage, the MOSFETs likely beat the IGBT in terms of forward drop. The Rds(on) of a power MOSFET runs as something like the square of the breakdown voltage. At low volatges, it can be quite low. The on voltage of the IGBT contains the forward drop of a large silicon diode.