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Re: Capacity Value Transformation

You could probably use a variac and have a totally tunable PFC device.  It
would take a little thought but is technically sound.

A very fun and new idea!!

Cheers,

	Terry


At 02:23 AM 04/22/2000 +0100, you wrote:
>
>Hello Coilers:
>
>While reading a text on A.C. motors I came across an interesting circuit
>that might have application in Tesla coil power supplies.  The value of
>a capacitor can be increased by the use of a transformer, as in this
>example.  A transformer with a primary/secondary voltage ratio of 1:2
>has a 20 uF. capacitor connected across its secondary.  This causes an
>apparent capacity equal to the ratio squared times the capacitor value,
>in this case 80 uF., to be across the primary.
>
>I'm wondering if by using a relatively low KVA rated 1:2 ratio transformer
>one could achieve power factor correction with relatively small values of
>PFC capacitors.  This would be particularly useful for larger coils that
>require capacitors in the hundreds of micro-farads for PFC.  The primary
>of the "capacitor transformer" would simply be paralleled with the MOT or
>pole pig primary.  One cap of 40 uF., a readily obtainable value in oil
>filled motor run caps, would yield an apparent capacity of 160 uF. in the
>power transformer primary circuit.
>
>At present I do not have the facilities to check this idea out in actual
>practice, so I'd be interested in hearing from anyone who does try it.
>Thoughts, criticism, and other comments are of course welcome.
>
>
>73, Weazle, VE3EAR/VE3WZL
>
>Listening: 147.030+ and 442.075+
>E-mail:    weazle-at-hurontel.on.ca
>           or ve3ear-at-rac.ca
>Web site:  www.hurontel.on.ca/~weazle
>