Re: NST filters

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Peter,

At 04:55 PM 4/25/2001 -0700, you wrote:
>Terry et al,
>            I notice your NST-filter circuit placement is this:
>
>    NSTsecondary - RCfilter - SafetyGap - TankCap
>
>I've been trying this:
>
>    NSTsecondary - SafetyGap - 1kohm - TankCap
>    
>this way when my safety gap does fire it just goes zzzz, rather than BANG
>as when there is no resistor between the tank-cap and the gap.
>
>
>I assume this protects the caps against too much surge current during a
>safety gap firing (?).
>
>I wonder if the helps or hinders protection of the NST (?).

I have not studied this configuration but I think it is fine.  There may be
some RF with the safety gap fires with the filter caps in the circuit but
probably not too bad.

>
>Since my NST secondary has a DC resistance of ~50kohm an additional 1kohm
>cann't hardly be noticed (?), in fact for my small TCs (9-30 NST) I've
>never noticed the 1kohm-25watt resistors even getting warm, much less hot,
>as others have reported.

We want to keep the RF out of the transformer's windings.  Thus, the filter
caps and resistors are used as a lowpass filter to block the RF.

Cheers,

	Terry


>
>
>thanks in advance for any opinions,
>Peter Lawrence.
>
>