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Registered Member #90
Joined: Thu Feb 09 2006, 02:44PM
Location: Seattle, Washington
Posts: 301
The "best coil" is the one that delivers the most amount of energy in the right amount of time. This depends on factors such as inside diameter, length and desired inductance.
It really really helps to first choose the dimensions of the object you want to shoot. From this, you'll have a good idea of the coil's length and inside diameter.
I recommend a coil of two layers of windings, or three layers at the most. That is, a coil with low winding height will work better than thick coils that end up with a lot of wire farther away from the projectile. My experience has been that thin coils with thick wire will work better than others.
As for the desired inductance, that depends on each stage's capacitance value and the time you want the pulse to last. This is a little engineering puzzle for which you can tinker with an RLC simulator, an LC time table, and an inductor design calculator.
Registered Member #1107
Joined: Thu Nov 08 2007, 10:09PM
Location:
Posts: 792
8KJ is a LOT of power to be switching. You would be better off building a much smaller seperate cap bank for each stage switched by a scr. For the coil, it depends on how much power you are switching. A 400j bank (per stage) you would need 20g wire. A 300j bank you will need 22g wire, for a 250j bank you can use 24g wire and so on. The number of windings varys significantly with the projectile, weight of the projectile, barrell, and so on but generally you will need around 300 turns per stage.
Registered Member #1608
Joined: Sun Jul 27 2008, 12:20PM
Location:
Posts: 10
Indeed, I ment 8kJ TOTAL energy, rp. And no, I don't have a switch yet, because I yet have to figure out the fastest switcher for these high current's.
Registered Member #1407
Joined: Fri Mar 21 2008, 07:09AM
Location:
Posts: 222
teslacoolguy wrote ...
8KJ is a LOT of power to be switching. You would be better off building a much smaller seperate cap bank for each stage switched by a scr. For the coil, it depends on how much power you are switching. A 400j bank (per stage) you would need 20g wire. A 300j bank you will need 22g wire, for a 250j bank you can use 24g wire and so on. The number of windings varys significantly with the projectile, weight of the projectile, barrell, and so on but generally you will need around 300 turns per stage.
300 per stage? i thought you have to decrease number of turns for every stage for the speed to build up
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Best coil and fastest switching system for 8kJ
? Nice gun though.