how do I connect my SCR to my coil gun?

I have 5 SCRs that iam planning to hook up to my coilgun in parallel circuit, how do it do it? (where does the + & - terrminals go, what do i attach to my coil, and does it need a battery? if it does, where?)

thanks

2 Answers

Relevance
  • Gary H
    Lv 6
    1 decade ago
    Favorite Answer

    5 SCRs in parallel is probably a waste of effort - what will happen is that the most sensitive SCR will turn on first and dissipate the majority of energy before most of the rest even begin to turn on. That is, assuming your coil is fairly low inductance and therefore the power pulse width is less than a few dozen microseconds wide.

    You would have the coil and the SCR in series, across the cap bank, and assuming a negative circuit common, the cap bank "+" to one end of the coil, the other end of the coil to the anode of the SCR, and the cathode of the SCR to common. Once you apply the pulse to the gate of the SCR that will make it fire, it will remain conducting even after the pulse has terminated until the current falls below the holding current level, so you should insert a switch between the cap charging circuit and the cap(s), which you should open once the caps are charged. Then you fire, and the SCR/coil will drain the cap bank. Once you're sure the caps are fully discharged, you can then close the switch for another go. If you close the switch before SCR current has dropped below it's holding current, the SCR will keep conducting, loading/shorting your cap charger. You should read up a bit, start with

    http://en.wikipedia.org/wiki/Silicon-controlled_re...

    Be careful, you're messing w/fire here, in terms of both the voltages you're probably using to charge your caps, and of course the projectile. Zero tolerance for anybody who would treat such a thing as a toy, ok? If you're not mature enough to have due respect for such a device, please find another hobby. All standard disclaimers apply, this is not kid's stuff, ok?

    BW,

    GH

  • Anonymous
    1 decade ago

    You need a big capacitor. The capacitor connects to the coil in series with the SCR. You also need a circuit to charge the capacitor. A battery will not give enough voltage for this, so you need either a transformer or an inverter. Be sure not to exceed the voltage or current rating of the SCR.

    It wouldn't hurt to learn a little basic circuit theory before attempting such a project. That way, you will live longer! At any rate, please do us all a favor and do not reproduce before attempting this project!

Still have questions? Get your answers by asking now.