Coilgun site, I have a question about the three stage SCR

[blueroomelectronics]

I was looking at the three stage coilgun described here
https://www.anothercoilgunsite.com/nf-home.htm
and a question about using SCRs as the coil controllers came to mind.

An SCR will stay on as long as DC current is applied, so if you're triggering three coils then by the time the last one fires won't they all be engaged?
Is this not inefficent?

 

[ericgibbs]

hi bill.
Had a look at your link.

The way I read it, the 3 SCR's, one for each capacitor bank, once fired will discharge their respective capacitor into their own coil.
So they will switch off, once their charge is dumped into the coil.

Any idea what sort of range you can achieve with this and weight of shot.?

 

[blueroomelectronics]

Ahh I guess the blue & black squares are caps. I suppose that would work, wonder if the relay arcs and pits. He's switching lots of amp there.

 

[Hero999]

Just make sure the LC oscillator is critically damped to reduce the posibility of the back EMF damaging the SCRs and capacitors.