coil gun power supply

.... a little o.t.

zenador said:

Cockroft-Walton Multiplier .

Click to expand...

I was privileged to hear a lecture by E.T.S. Walton ... a few years ago... probably 1975 or 76.
This was essentially some interesting anecdotes and trivia concerning the distinguished scientists at the Cavendish Laboratory in Cambridge, England, during the first part of the 20th century. Their efforts were focused on discovering the structure of the atom, and the mechanism of nuclear fission. There were stories about J.J. Thompson ... a noted theorist, but apparently not much aptitude for practical experiments, C.T.R. Wilson ... a Scotsman who invented the cloud chamber, Ernest Rutherford, and Lord Rayleigh.
One interesting comment ... it was a common practice within the institute to save every scrap of metal that was not being used or was to be discarded, in order to melt down and use again.... Not much of a budget, apparently.
One of the main achievements of Walton and Cockroft was to invent a method of obtaining a sufficiently high voltage to accelerate subnuclear particles .... to achieve the breakup of several chemical elements.

for additional details ... see the second listing at this page:
Ernest Walton: Biography from Answers.com

Is your coil gun being modified for use as a harpoon launcher? The microwave transformer provides adequate voltage to expel the projectile a very short distance with great force. Choose wires that can withstand this powerful surge.
Remember that the transformer may exhibit ultrasonic and magnetism properties. You can try using a TV horizontal output transistor to drive the transformer.

TV horizontal output transistors ROCK! I have hammered those little bastards till they glow and they hang in there, cycle after cycle. Puny mosfet's and lesser bjt's puke out the magic smoke and die, but the TV horizontal output transistor hangs tough.

(until you put them in a TV, then they are usually the first thing to go)

There's a slew of good modern N-channel MOSFETS that carry on the valiant tradition of those TV horizontal output transistors of yore, with low Rds on resistance, built-in zeners for stupidity protection, and breakdown voltages that make thyratron tubes nervous about their job security. I'm currenty using an STY60NM50 that has the ability to laugh off a 240A pulse, shoulder 500V, and present a piddling .045Ω of on-state resistance. Costs twenty-five damn dollars each, but they have crushed similar-rated IGBT's under their SOA curves in one of my applications.