Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!ub!csn!boulder!boulder!rainer From: rainer@boulder.Colorado.EDU (Rainer Malzbender) Newsgroups: sci.electronics Subject: Re: How to make a RAIL GUN? Message-ID: <1991Mar26.094649.28010@colorado.edu> Date: 26 Mar 91 09:46:49 GMT References: <27EE910A.10011@ics.uci.edu> Sender: news@colorado.edu (The Daily Planet) Distribution: usa Organization: /usr/local/lib/rn/organization Lines: 30 Nntp-Posting-Host: rhubarb.colorado.edu In article <27EE910A.10011@ics.uci.edu> alleyne@ics.uci.edu (Brian Derek Alleyne) writes: > > c c c c c c c >-=--=--==----===------===----------===---------------===-- >-=--=--==----===------===----------===---------------===-- > c c c c c c c > 1 2 3 4 5 6 7 > The astute reader will no doubt recognize this as a mass driver, not a rail gun. A rail gun is much simpler in that it doesn't need position sensors, it's just a big cannon. A bit of useless history: I worked on one of the early mass driver projects with Gerry O'Neill, for potential lunar applications. His counterpart at MIT, Henry Kolm, headed the Magneplane project (a little levitated train), and was also into mass drivers. I lost of track of what happened after 1980 or so, but I know Kolm became more involved with rail guns. I think the government did, too, I suppose because of the sheer simplicity and brute force of the things. Mass drivers are trickier. FYI, we used optical triggers to sense the approach of the projectile, which in turn dumped huge amounts of current through the coils using SCR's. The above non-linear spacing of the coils makes it easy to have fixed-frequency pulses energize the coils, but you lose the power (for a given length) of regularly spaced coils. -- Rainer Malzbender, PhD "It's not the bullet that kills you, it's the hole." Dept. of Physics (303)492-6829 -Laurie Anderson U. of Colorado, Boulder rainer@boulder.colorado.edu 128.138.240.246