Re: Triggered gap and safety gaps

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

Original poster: "Metlicka Marc by way of Terry Fritz <twftesla-at-qwest-dot-net>" <mystuffs-at-orwell-dot-net>

bert,
in my early "RAW" circuit, i didn't provide this return path. i grounded
the case of the nst, the dimmer case and the nst filter circuit ground
term., could this have been why the safety gap would fire every once in
a while? i wondered were the trigger energy was going, i thought maybe
it was following the main tank energy around the primary?
i am setting up to try terry's setup now.
marc m.

Tesla list wrote:
> 
> Original poster: "Bert Hickman by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>
> 
> Jonathan,
> 
> A path needs to be provided for current to flow for the triggering pulse.
> This is the trigger return path I was referring to. When using an NST
> HV source, the trigger return path can be provided via the center tap
> of the NST. Trigger pulse current flows through C1, the spark gap trigger
> electrode to one of the main gap electrodes, and back through the NST
> center tap (via a direct connection per Terry's most recent circuit).
> 
> However, in the case of isolated secondary HV transformers (pole pigs,
> radar transformers), you will have to "create" a return path using the
> circuit I previously provided for Weazle McCreath, See Case 2
> below.
> 
>                  ------------            C1
>         Pri      |          |    HV      | |               to
>       <----------| Trigger  |------------| |---------->  trigger
>                  |  Coil    |  Output    | |            electrode
>                  |          |           30-50 kV
>    From          |          |
>   Dimmer         |  Common  |
>    Ckt           ------------
>                       |
>       <---------------o-------------------------------> Ret
>     Mains                              Case 1: to center tap of
> NST
>    Neutral
> 
> 
>                          Case 2
>                      Isolated Xfrmrs
>              (pole pigs, RADAR transformers)
> 
>                   C2                   C3       R3-R4 = 15 kV Bleeders
>                   | |                  | |      C2-C3 = 40-50 kV Doorknobs
>           |-------| |--------o---------| |--------|      (100 - 500 pF)
>           |       | |        |         | |        |     Use cascaded caps
>           |                  |                    |      for sufficient
>           |                  |                    |       HV isolation
>     H1    |        R3        |          R4        |     H2
>     o-----o-----/\/\/\/------o-------/\/\/\/------o------o
>     HV1           15 kV      |         15 kV            HV2
>   Output          (Min)      |         (Min)           Output
>                              |
>               Ret            |
>                 <------------|
> 
> 
> Hope this helped!
> 
> -- Bert --
> --
> Bert Hickman
> Stoneridge Engineering
> Email:    bert.hickman-at-aquila-dot-net
> Web Site: http://www.teslamania-dot-com
> 
>