RE: Pig PFC (was Re: Inductive Kick LTR Pig Systems)

[Terry Fritz <twftesla-at-uswest-dot-net>]

Hi John,

"I" have not seen a Tesla coil that could appear only "resistive" to the AC
line without PFC caps.  Typically, they have very poor power factor!  Am I
missing something?

Of course, the voltage and current entering the primary transformer is not
affected by the PFC cap, just how the whole mess apears to the AC line side.

Of course one should not add too much capacitance to the AC line or odd
hormonic things "may" happen...  But that is unlikely in our situations. 

Cheers,

	Terry



At 10:59 AM 8/29/00 -0700, you wrote:
>
>PFC for a pig may not be a good idea. The power factor on the line side is
>the same as the power factor on the load side. Of course this assumes no
>other loads on the line side. With a properly operating Tesla coil the load
>appears as resistive and the power factor is about 100 percent. A PFC
>capacitor would give a leading power factor which is undesireable.
>
>If PFC with a pig is apparently giving longer sparks it is due to something
>about the ballast and circuit adjustments. Experiments like this should be
>checked out with the proper instrumentation before conclusions are made.
>
>John Couture
>
>-----------------------------
>
>
>-----Original Message-----
>From: Tesla list [mailto:tesla-at-pupman-dot-com]
>Sent: Tuesday, August 29, 2000 7:00 AM
>To: tesla-at-pupman-dot-com
>Subject: Re: Pig PFC (was Re: Inductive Kick LTR Pig Systems)
>
>
>Original poster: "Malcolm Watts" <M.J.Watts-at-massey.ac.nz>
>
>Hi Ed,
>
>On 28 Aug 00, at 20:39, Tesla list wrote:
>
>> Original poster: "Ed Phillips" <evp-at-pacbell-dot-net>
>>
>> Tesla list wrote:
>> >
>> > Original poster: "Malcolm Watts" <M.J.Watts-at-massey.ac.nz>
>> >
>> > Hi all,
>> >          After putting my foot in my mouth already on this
>> > subject I am satisfied in my own mind that the sole purpose of
>> > PFC for a pig is to cancel the primary magnetizing inductance
>> > in the transformer. The ballast and primary cap should be self-
>> > cancelling if the charging is mains resonant. A crude model of
>> > the transformer is that of an ideal transformer with its
>> > primary shunted by a magnetizing inductance (Lp). In other
>> > words, PFC for a pig sounds like a jolly good idea.
>> >
>> > Malcolm
>>
>> 	One would think that the PFC should go on the line side of the ballast.
>>
>> Ed
>
>Agreed. And it probably is a dynamically varying (with load)
>quantity that is required.
>
>Regards,
>Malcolm
>
>
>
>
>