On 8/22/15 2:10 PM, Matthew Sweeney wrote:
Now I have three perfect 15,000v 250ma NST's just sitting waiting for a purpose - so I think it's time to start planning a new build. I have never built a proper solid state coil and am considering this option. But a traditional rotary spark-cap coil with high-voltage capacitors would be much less effort. The secondary will be 5 Feet and using enameled magnet wire. I'm looking for good sources of (cheap) high voltage capacitors and much info on recent developments in the field.
The spark gap coil state of the art for smaller coils (<10s of kVA) would probably be the MMC (multi mini capacitor): paralleled strings of polypropylene dielectric capacitors designed for high di/dt. A string of 10 2kV, 0.15 uF caps gives you a nice 15nF, 20kV capacitor which is tough and will set you back about $60.
CHeck out the Cornell Dubilier CDE 942C20P15K, for instance.. You can do other voltages and capacitances to customize. The price drops pretty quick in larger quantities. I especially am interested in
inductor usage to prevent spikes back to the NST. Also I need some advice on secondary wiring cable is there a preferred variety for recent coils? Ill use copper tubing for primary. I may also build my own rolled capacitors but I'm thinking obtaining newer HV caps in a bank may actually be cheaper.
Rolled caps have pretty much gone away since the availability of the snubber PP caps like the 942.
The other alternative for bigger coils is surplus caps from Maxwell Labs which turn up occasionally, or similar caps from lasers and radars from other countries.
_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla