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Re: Safety gaps destroyed my Neon ?
Hi Robert,
> I have been arguing against using a grounded center tapped NST safety
> gap for years because I feel this is asking for trouble as you pointed
> out. You just cannot guarantee that both gaps will light
>simultaneously to stop the voltage surge with such a gap system.
>One half going into the conductive state might well reduce the overall
>surge sufficiently to prevent the second from lighting at all. At the
>same time, a healthy surge then becomes directed to where it can do
>damage. Just my opinion.
Iīm not sure I can agree with you here. If you use a 2 piece SSG (esp
on center tapped xformers) you can still raise one side of the xformer
to dangerous voltage levels (and the 2 piece gap wonīt fire) AND this
SSG is nothing more than a second main gap. The voltage is not bled
off to a ground (zero volts) potential. In other words, the current will
be forced through the tank circuit once again. If there is *any* high
frequency superimposed on top of this voltage AND you are using
any kind of filter, you will have to force all this through the filter
in the *wrong* direction. This may or may not work (the time
necessary, will become a problem). In any case, you will have RF
floating (at some undefined potential) around the xformer, which
is not instantly bled off. Personally I think a 3 piece SSG alone
is good enough. I donīt use any other filters, etc. I have not lost
a NST yet (and my SSG has fired lots of times). The 3 piece
SSG will bleed of any overly excited electrons (read: overvolting)
to a pretty firm zero potential. If only one half of the gap fires,
then obviously, the circuit has a raised potential only on one side.
The gap will clamp the voltage down to a safe potential. If the
surge is not clamped hard enough, the second gap should cut
in and save the other side of the transformer.
Coiler greets from germany,
Reinhard