- Jul 4, 2008
One of the reasons you lost output moving up toroid size is because you don't have enough turns on your secondary. The effects the magnetic fields characteristics and as such fails to energize the full winding length.Woops... I ment primary. Your secondary is fine for now. You don't have enough power for anything too much larger. 3" coil is probably the largest you can use.So I was right in thinking this secondary is too small then! Good to know. What size would you recommend for a larger coil using the same MMC/NST? Is 3"x15" going to be big enough to get ~1ft streamers? I'd rather not go so large that streamer length exceeds secondary height, because then I need to do serious primary side strike protection.
One word; AWESOME. How the heck do you wind such large secondaries? I assume you have some kind of motorized jig?
Big secondaries require a motorized or (I prefer) hand cranked jig. Reason is that you want to slowly turn the wire onto the coil form as perfectly as possible. At larger powers, a small break in the insulation on the wires can lead to a breakout or racing arc.
Just to clarify the SSTC thing. small DIY SSTC, are quite inexpensive, but when I consider TCing I like anything that can give +70" discharges. SSTCs that can deliver this kind of power are $$$$'s! Those are usually DRSSTCs, ones that utilize huge IGBTS. Oh yes, they are REALLY expensive.
DRSSTC that produce the shows seen in Vegas (singing coils) are $10,000s each or more.