Re: Higher current same capacitor question

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

Original poster: "bob golding by way of Terry Fritz <twftesla-at-uswest-dot-net>" <yubba-at-clara-dot-net>

Hi Alan,
    Going on my experience with moving up to a higher power transformer the
bigger problem will be quenching
your gap. You are going down in voltage which won't help either. If you
current limit the transformer properly
you cap should be OK .just don't be tempted to run at too high a power if
you aren't in tune. Get as much
airflow as you can though the gap. Make sure you have some control over the
airflow though as too  much will
stretch the arc which might blow your caps. If you have a well set safety
gap you ought be all right. What is
the spec of your MMC? Good luck.

bob golding

Tesla list wrote:

> Original poster: "Kelly & Phillipa Williams by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <kellyw-at-ihug.co.nz>
>
> Hi All,
>
> I have a question to do with capacitor sizes, current capability of the
> transformer,
> cap wear and tear etc.
>
> I have a Tesla Coil that is designed for a 15kV rms 120mA NST farm using a
> 40nF
> MMC capacitor. I have recently aquired a 11kV rms 5kVA power distribution
> transformer, and I am wondering if I can take advantage of the increased
> current capabiltiy of the power transformer.
>
> My power supply is 230 V, 50Hz, 20 Amps max, which corresponds to
> 418mA on the secondary of the power transformer.
>
> My 40 nF capacitor is way under resonant size for this transformer,
> which is 121 nF  !!
>
> Question 1: I have a static spark gap, so could I set the gap to fire at
> 10-11kV
> and let the system run at an insanely high bps without damage to the MMC?
> Would the RMS current on the capacitor be way over their rating?
> Can I use the full current capability of this transformer with risking
> damage to the MMC?
>
> Question 2: I have two oil-filled plate caps that are not currently being
> used. However, I suspect that I CAN'T use the plate caps and the MMC
> together at all because of the differing dv/dt's of the capacitors - the MMC
> will discharge very fast and then the plate caps will expend energy
> re-charging the MMC. Is this correct ?The plate capacitors are 15kV DC 11 nF
> and        30 kV DC 5nF .
>
> Comments ? Suggestions ?
> Being a student, I can't buy any more MMC caps for a long while, and I can't
> afford to break the MMC I have.
>
> Thank you very much,
> Alan Williams.