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Home-Scale Coilgun Schematic April 26, 2004 - There will be more on this page shortly. I don't currently have access to my coilguns, but I will in two weeks. This is the most recent update. My home-scale coilgun will be designed to fire a 40mm long, 2mm diameter iron projectile at around 55 m/sec. This will acheive a distance of around 54 feet when fired from 3 feet above the ground, and will hit the ground after approximately 0.305 second. It will operate from a rectified isolation transformer (170v DC) and charge 25 1000uf capacitors for a total of 361.25 joules. The coil will be wound from AWG 17 magnet wire and will ultimately be triggered by an optosensor circuit and have multiple stages. The coil will be conducting while the sensor is blocked, so I will use a solenoid of some sort to give the projectile an initial velocity. I have my isolation transformer, 15 capacitors, and my AWG 17 coil set up now. I think I'll mount the coil and switch on a swivel-mount for a turret effect or on a semi-mobile rifle-style skeleton connected to the capacitors by long wires. My last operating setup consisted of an 800v 1A diode rectifying the output of the transformer. This 170v DC was fed into a 160uF photoflash cap, a 470uF 200v cap I got out of a TV, and two pairs of series connected 470uF 100v caps (a total of 470uF 200v). This gave me 15.9 joules, and I acheived 4 m/sec. Ugh, a measly 0.2% efficiency. Then again, I was using an incredibly bad coil. I hope I can determine the mass of my projectiles and the exact voltage on the capacitors soon, so I can calculate my efficiency. Update! I have decided to use this multistage schematic as my final destination. Therefore the IGBT Step has been replaced with a pulsed SCR step. I have also lowered the efficiency requirements for each stage, as efficiency is seeming much harder to attain and I am limited by 1000uF steps in the capacitors for now. I plan to bring this coilgun through several stages before the final version (to give me time to make some money). Partial Test: A test of a few of my components - At least one of all crucial components tested! (Done) Coil Test: A test of a 17 AWG coil recommended by the MGC - Done! Full Test: A test of at least 15 capacitors and all other components - Done! SCR Switch: An SCR switch is implemented - Done! SCR Optimization: The coilgun acheives 1% or better efficiency w/ an SCR - Not Done Pulsed SCR Switch: Two SCRs are used with a pulse generator to turn the current on and off - Not Done Optodetector Switch: An optodetector circuit uses two SCRs to activate the gun - Not Done Optodetector Optimization: The optodetector switch acheives 1.5% efficiency or better - Not Done Dual-Stage Implementation: A second coil is wound, attached, and tested - Not Done Tri-Stage Implementation: A third coil is wound, attached, and tested - Not Done Tri-Stage Optimization: A three-stage setup acheives 2.5% total efficiency or better - Not Done The third stage will be the largest step up, and I doubt I can even acheive it. If I do, however, my hobby will indeed be powerful, firing at between 67 m/sec and 126 m/sec, depending on the mass of my projectile (which I still haven't determined!). Progress: Able to fire - Done Able to knock over a can - Done Able to puncture a can and stick - Not Quite Able to puncture a can straight through and knock it over - Not Done Able to puncture a can straight through without knocking it over - Not Done Able to stick 1" into a piece of wood - Not Done Able to blast right through a piece of wood - Not Gonna Happen