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NST protection
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From: Sulaiman Abdullah [SMTP:sulabd-at-hotmail-dot-com]
Sent: Thursday, April 16, 1998 4:29 AM
To: tesla-at-pupman-dot-com
Subject: Re: NST protection
>From: Malcolm Watts [SMTP:MALCOLM-at-directorate.wnp.ac.nz]
>Sent: Tuesday, April 14, 1998 5:13 PM
>To: Tesla List
>Subject: Re: NST protection
First I'd like to thank all who contributed to the (hopefully)
longer life of my next NST !, thanks guys.
Malcolm,
Thanks for the info, do you mean throw-out just the chokes,
(keeping the 1.1 nF per leg to ground and 7k series resistors)
or remove all devices from NST to safety and main spark gaps?
Anyone...
NST/rf filters store energy in parallel capacitors and series
inductors, for the filter I made the discharge time is longer
than the calculated 'ringing-down' time of the primary resonant
circuit (time to first null calculated based on k).
Could energy stored in the filter make it difficult to quench
the main gap at first null? Just curious if anyone has considered
this already and has a simple answer. Bye ... Sulaiman
>
>Safety gaps can't cause nasty voltages. My advice - throw the chokes
>away and get your transformer secondary leads as short as possible.
>If there is no wire/chokes etc between the main gap and transformer
>secondary, there is no way a safety gap set wider than the main gap
>can possibly fire. Again, research I've done in the past suggests
>that any parasitic energy storage component between the transformer
>secondary and main gap is responsible for the severe voltage hikes
>and these occur *when the main gap initially fires* as an energy
>source is then trapped between a virtual short circuit and the
>transformer secondary.
>
>Malcolm
>
>> Was it coincidence that the NST failed under the above conditions?
>> or is a spark-gap (even a "safety" gap) directly across an NST a
>> bad idea? Comments ? ............
>> Bye ... Sulaiman
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