NST's Shorting Out

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "James Zimmerschied" <zimtesla@xxxxxxx>

Original poster: <mailto:MARTINFRYML@xxxxxxx>MARTINFRYML@xxxxxxx


Hello all,



I just rebuilt my Tesla Coil and have run into problems at higher power inputs.
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Martin,
I have used asynchronous rotary gaps with NST's a little and have 
noted that when the break rate is low (e.g. 189 BPS in your set up) 
that the safety gaps fire a lot indicating high voltage kick back 
into your NST circuit. I have not killed a NST but it is part luck 
and part the filter net work that protects the NST.

You can get better performance with a synchronous rotary gap and once 
the phasing issues are solved, avoid excessive kick back into your 
NST's. Getting a synchronous motor is not all that easy - you can 
modify a regular induction motor by machining flats on the rotor.

If you want to keep the current rotary system, I suggest adding 
another fixed electrode (your data shows one fixed electrode with 21 
rotating electrodes). I would consider using a DC motor so that you 
can vary the speed. A 300-400 BPS would keep the kick back to the NST less.

Asynchronous rotaries work well with PT's or pole pigs because they 
are much more robust than NST's when it comes to kick back - after 
all they are designed to accommodate lightning on the power grid.

Jim Zimmerschied