Re: Tiny Spark Gaps? (fwd)

[<sroys@xxxxxxxxxxxxxxxxx>]

---------- Forwarded message ----------
Date: Thu, 14 Oct 2004 10:44:29 -0400
From: B2 <bensonbd@xxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: Re: Tiny Spark Gaps? (fwd)

Hi All,
     Yes with a qualification.  I have used these as spark gaps for a small 
Tesla Coil.  They can also protect a transformer.  It depends upon the power 
level of the transformer.  You can put several in series (in parallel across 
the transformer) to clip the transients coming back from your main spark 
gap.  You may need some resistance between the gaps and the transformer, and 
between the gaps and the main spark gap of a Tesla Coil.  In addition, 
varisters connected directly across the transformer will also improve the 
protection of a transformer.  The varisters need to be connected in series 
such that they just barely get warm to the touch at the full operating 
voltage of the transformer.

     Hippotronics also had another technique that they used to protect their 
big transformers used for HV power supplies.  They used spark plugs as spark 
gaps across the input leads.  Varisters (VL130LA20) are a better choice 
nowdays.  I believe that they were trying to prevent line transients from 
entering the prmary.  These can also cause the secondary to exceed safe 
operating voltage.

     In summary, use varisters on both sides of your transformer.  Use the 
glass spark gaps on the transformer secondary to aid the varisters in 
clipping transients.  The glass sparks may require a resistor network to 
prevent power arcing.  Experimentation might be in order.  Please cover the 
glass spark gaps with heat shrink or something else to contain the 
supersonic glass shards that could be ejected should they explode.  A part 
number and manufacturer would be useful information for determining their 
energy handling capabilities.

Barry

----- Original Message ----- 
From: "High Voltage list" <hvlist@xxxxxxxxxx>
To: "hvlist" <hvlist@xxxxxxxxxxxxxxxxx>
Sent: Friday, October 08, 2004 12:54 PM
Subject: Tiny Spark Gaps? (fwd)


> Original poster: <sroys@xxxxxxxxxxxxxxxxx>
>
>
>
> ---------- Forwarded message ----------
> Date: Fri, 8 Oct 2004 11:48:51 -0500
> From: Carl Litton <Carl_Litton@xxxxxxxxxx>
> To: High Voltage list <hvlist@xxxxxxxxxx>
> Subject: Tiny Spark Gaps?
>
>
>
> Carl Litton
> Guest Assistance
> Hilton Hotels Corporation
> 901-374-5747
>
> Throughout the charging systems of a very high voltage capacitive
> discharge system, we are finding small devices that appear to be tiny
> spark gaps in cylindrical glass cases.  ~1cm x 1cm clear tube with metal
> end caps and axial leads, interior surface of end caps is strongly
> convex.
>
> Are these things what they seem?  Would they be useful in transformer
> protection circuits?
>
>
> Carl Litton
> Hilton Hotels Corporation
> 901-374-5747
>
> [Barry...?  This sounds like a question for you... SRR]
>
>
>