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Re: LTR cap BPS?

Original poster: "Bunny Killer" <bunikllr@xxxxxxxxxxxxx>

Hey Jamie...

when using an LTR cap and NST the spark gap is the item that sets the majority of the break rate...

the cap will fill to the highest voltage the NST can provide during the time it takes to make a complete sine wave ( well it will be a tad less due to resistances) if your spark gap ( lets say its a static gap) is set to fire at some voltage due to its gap width, the so called break rate ( in theory ) should be 120 BPS ... this is considering that the gap width is set for maximum voltage of your NST ( which is pretty much impossible to set without dedicated measuring equipment) if you set the gap too wide the voltage will and can build to better than 2 times its rated voltage ( and by the way the voltage ratings you see on the NST are RMS ratings... this is sort of an average rating of the sine wave, not the peak ratings the transformer is capable of... a good reason to get your caps voltage value at 2 times the name plate rating)

if the gap width is set smaller, allowing the spark to be created in the gap before the sine wave peaks, it is possible to have 240+ BPS...
what happens in this situation is that the voltage builds and then jumps the gap ( lets say at 50% of max NST voltage) the resonate circuit will keep the voltage up a bit allowing the NST to recharge the cap set quickly and POP another spark jumps the gap before the sine wave peaks... this can happen several times before the peak of the sine wave.... thus 200+ BPS

so in a nut shell the BPS should be 120 and resonate action will cause it to go higher...

why 120? a complete sine wave has both a "positive" voltage swing and a "negative" voltage swing.. thus 2 swings per complete cycle ( and there are 60 complete cycles per second in general USA applications
since the cap is capable of being charged in both directions ( an AC cap) it is quite capable of the 120 BPS rate

hope this helped..

Scot D



Tesla list wrote:

Original poster: "Black Moon" <black_moons@xxxxxxxxxxx>

Hi, I was wondering, when using a LTR cap an a NST, is your break rate spost to be around 60? is the resonant action what causes it not to be 120+?