Re: DC coil without the voltage doubler resoance charge inductor?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Conner <steve@xxxxxxxxxxxx>

At 07:23 05/05/05 -0600, you wrote:

> After pounding my head I see no advantage to a HV charge inductor
...
> I am thinking of retaining my welder and ballasting the LV
> side of the pig.

If you are using a filter capacitor (such as the 4uF 20kV unit you 
mentioned) then you MUST use a HV charge inductor otherwise the HV filter 
cap will discharge through the spark gap. You can use a resistor in place 
of the inductor but be prepared to lose 50% of your power.

I have heard of some people using a dual rotary gap that charges the tank 
capacitor through one set of contacts and discharges through another, which 
might prevent the filter cap discharging as above, but I'm not convinced it 
would work efficiently without a charge inductor. There is just no lossless 
way to charge one capacitor by connecting it directly to another- so you 
would lose 50% of the power in violent arcs at the charging gap.

LV side ballasting only works if there is no DC filter cap (such as on 3 
phase DC coils- like Syd Klinge's CAUAC- where no filter cap is required)


Steve Conner