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Re: A Trap For The Unwary





---------- Forwarded message ----------
Date: Mon, 13 Oct 1997 15:26:11 GMT
From: Jim Fosse <jim.fosse-at-bjt-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: A Trap For The Unwary

Hi Malcolm,
	Welcome to the school of hard knocks;) This reminds me of the
time I build a 15KV esd tester at work. No matter how hard I drove the
TV flyback xformer I couldn't get more than a few thousandths of an
inch of spark from it. While scoping the drive circuitry at high
power, I smelled hot phenol. I'd "tie rapped" the flyback core to the
vector board with 2 turns of bare #28 wire - and then soldered them
for good measure. Amazing how much power 2 shorted turns can suck out
of a transformer;(

	cheers,

	jim


>    I should have known better - that resonator with its topload 
>should have been resonating well below 200kHz rather than the 230 I 
>had noted. I even went back and checked to make sure I hadn't tuned 
>into one of the higher order resonances. I even had the ballpark 
>frequency recorded a few pages back in my notebook. I should have 
>b****y well checked before hacking into the primary. As a result, I 
>am going to braze the primary pipe back into one piece today before 
>rebuilding the original.
>    The problem? Despite the obvious pressure the contacting wire 
>going from the top of the secondary was exerting on the toroid, it
>wasn't making contact due to oxidation. Of course it did with the 
>first few real volts going in thereby completely detuning the thing.