A few arithmetic errors, corrected below.. jimlux wrote:
Quarkster wrote:Nicholas - A few areas of concern are revealed by your photos: 1. It looks like your tank wiring to the MMC and spark gap is extremely small gage stranded wire (#16 AWG?). All the interconnects between primary coil, spark gap, and tank capacitor need to be fairly heavy gage (I recommend no smaller than #12 AWG for a small NST powered coil). The peak current in the tank circuit can be hundreds of amps when the spark gap fires and the tank capacitor dumps all of its energy, and #16 AWG is not adequate.This is just not true. The peak current may be relatively high, but even so, the losses just aren't that high, compared to the losses in the gap itself. Consider that the difference in diameter between AWG 12 and 16 is about a factor of 1.4. Therefore, the loss goes as the same ratio.
This assumes that for RF, the AC resistance runs roughly as the circumference of the conductor. For DC, where the entire cross sectional area is used, the resistance ratio will be more like 2:1.. (a bit more.. 3 gauges is twice/half the resistance)
Let's assume for a moment that you have AWG 10 wire (just because it's easy to remember the resistance.. 1 mOhm/ft).. Say you have 2 feet.. that's 2 mOhm total. Also assume that the peak current is 1000 Amps ( if Cpri is 0.1 uF and Lpri is 30 uH, 15kV turns into 866A, assuming NO losses anywhere else)So the voltage drop across that couple feet of wire is 2V.. compare that to the 100V or so across the gap.Now, go to AWG 16, which will have twice the resistance (at DC).. Now the drop in the wire is 4V.. Overall the loss has increased by 2/104, or about 2%...
Here, I used the DC resistance, which is inconsistent with my assertion above that one should use the AC resistance, which in turn is proportional to circumference. So, AWG16 is 1/4 the circumference of AWG10.. so 8V drip vs 2V, for a 4% total loss.
Sorry, all.. _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla