Re: marx chokes

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

Hi Ed,

On 13 Apr 2005, at 18:49, Tesla list wrote:

> Original poster: Ed Phillips <evp@xxxxxxxxxxx>
>
> "Did I mention the "rods" were ferrite? I think I may have forgotten.
> I'll collect some more concrete info to post tomorrow. The chokes
> could usefully have had a lot higher inductance than they did. They
> shouldn't saturate as they have end - end airgaps.
>
> Malcolm"
>
>  I erased the original note but sure got the impression your windings
> were on ferrite rods.  As for saturation, I'm not sure that the air
> gap will be enough; it's all in the effective "volts per turn".  I had
> problems at very much lower power levels when I did an experiment to
> see if I could use a movable ferrite rod (actually several of them,
> 1/2" dia x 2-1/2" long) to tune a 4 mH loading coil for a LF antenna.
>
> Ed

Yes, well I can't guarantee it didn't happen but if it did, the
inductance must have been sufficient because the scheme did work OK.
I don't think it should be that much of a problem anyway with the
discharge time being fairly short. After all, the initial current at
erection time would residual charge current and the voltage impressed
across the choke can't force an instantaneous current through it. In
fact that is why the scheme works.

Malcolm