Re: DSL-Diode Spark Gap Logic

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

Original poster: "jimmy hynes by way of Terry Fritz <twftesla-at-qwest-dot-net>" <chunkyboy86-at-yahoo-dot-com>


could you use slow diodes so the spark gap only has to conduct for the first
half cycle? 

 Tesla list 
>
> wrote:  
> Original poster: "Bert Hickman by way of Terry Fritz " 
>
> Hi Barry,
>
> Interesting experiment! That Spellman primary must have quite a few 
> turns, since it clocks in at over 1 mH. And, assuming the gap is 
> repetitively firing at 2500 Volts, the bang size is only a little over 
> 0.03 Joules and the peak primary current is only about 8 amps. This is 
> probably why both the gap and diode aren't being stressed very much. 
>
> Assuming the diode chain conducts half of the time, the peak voltage 
> drop in the diode chain's forward direction will likely be in the range 
> of 8-12 volts, while the spark gap's conduction voltage (assuming fill 
> gas is air) would be in the range of 150-200 volts (or about 10 times 
> lossier). Given that the heating of the diode chain is shared across 8 
> diodes, the relative temperature rise of a g! iven diode versus the spark 
> gap (due to I*E losses) sound about right. And, in theory, the overall 
> "lossiness" of the gap should be less with the diodes connected across 
> it versus alone.
>
> Did you notice any performance improvement with the diode chain 
> connected versus without? 
>
> Also, what kind of performance did you see either way (i.e., spark 
> length)?
>
> Thanks, and best regards,
>
> -- Bert -- 
> -- 
> Bert Hickman 
> Stoneridge Engineering 
> "Electromagically" (TM) Shrunken Coins! 
> http://www.teslamania-dot-com
>
> Tesla list wrote: 
> > 
> > Original poster: "B2 by way of Terry Fritz "
>
> > 
> > Hi All, 
> > I am about 1463 e-mails behind at the moment. Classwork will limit my 
> > reading until December. In the mean time, I had a free 30 minutes for 
> > experimentation. I tried the following: 
> > 
> > 1. Transformer is 4 kV, 30 MA bug zapper transformer. Trans! former HV 
> > output is connected to the tank capacitor via! 5 KOhm-50 Watt resistor plus
> > two 6 kV diodes (All Electronics) in series (12 kV total). 
> > 2. 0.01 uF MMC. 
> > 3. Resonant frequency-50 kHz. 
> > 4. Primary and secondary are from an ancient Spellman HVPS. 
> > 5. Secondary is pie wound-10 pies-4 inches winding length. 
> > 6. Victoreen-DSL-SGCA-2500D precision spark gap (fires at 2500 Volts within
> > 5 %-Haven't found another source) paralleled with 8 series connected diodes
> > (1N5408-1kV-400 Ampere surge-All Electronics, Digikey). 
> > 
> > Notes: Fired the coil for 1 minute. Unpluged it and then shorted out the 
> > MMC. Touched the SGCA-2500D and diodes. They were both barely perceptable 
> > warm. Under normal operation the SGCA-2500D would be too hot to touch 
> > after 30 seconds. 
> > 
> > Theory: The SGCA-2500D conducts for only 1/2 cycle. The diode string 
> > conducts for the other half cycle (extrapolation from Terry's research). 
> > 
> > Com! ments: It is interesting that such a low frequency diode works at 50 
> > kHz. More experiments at higher power as time permits. Interesting 
> > possibilities here. 
> > 
> > Cheers, 
> > Barry
>
>
>
>
>
>
>
> JImmy
>