Re: More Tuning/Debugging

To: tesla-at-pupman-dot-com
Subject: Re: More Tuning/Debugging
From: Jim Fosse <jim.fosse-at-bdt-dot-com>
Date: Wed, 18 Sep 1996 03:19:37 GMT
On Sun, 15 Sep 1996 22:25:13 -0600, Tesla List 
>From: Bert Hickman <bert.hickman-at-aquila-dot-com>
>To: tesla-at-pupman-dot-com
>Subject: Re: More Tuning/Debugging
>
>Jim Fosse said (in response to a post from Richard Quick):
>
>> However, given Richards 1.5 second delay factor, I would look for an
>> interaction between the PFC caps and the ballast and variac also.
>> Try removing most of your PFC caps and see if there is a significant
>> change in the time constant or behavior of the system. Don't remove
>> all of the PFCs because they prevent the voltage spikes from the
>> ballast from blowing your RFI filters and home electronics.
>> 
>Richard,
>
>I don't remember your pig-based system using any PFC's, although some of
>your early writings did suggest their use in conjunction with neons to
>keep overall current draw down. Based upon some of the work that Jim has
>done, plus your comments regarding lag in responsiveness, it would
>appear that the use of PFC's could help "neutralize" much of the
>inductive lag without increasing real power dissipation.

Good observation bert. I was fixated on LC response and totally missed
LR effects;(   I also "jumped to confusion", based on Richard's prior
post on PFC caps that he was using them in this system. He may or may
not, but I didn't verify it.

I just looked at his prior post:
>>>>>>>
This is perhaps compounded by the huge amount of inductance in
the system. Locally, if you start with the 50KVA pad mount
transformer that supplies my house (and a few neighbors), then
add in the arc welder, 60 amps worth of 240 volt Powerstats, and
25KVA worth of pig, we are talking about some serious inductance.
<<<<<<
no mention of PFCs.

> PFC's MAY also
>help suppress nasty voltage spikes from getting back into your (and your
>neighbors') mains. 
>
>I'm thinking about adding as much as 250 uF of fused PFC correction to
>help counteract the inductive reactance of my ballast & pig AND to
>hopefully keep me from blowing up all the other electronic goodies tied
>to the mains. 

Actually, with no PFCs, I did not damaged any electronic goodies in my
house - I took out the RFI filter between my ballast and the mains
instead;(  It was only after I added 23uF of PFC cap did the spikes
get into my home mains and take out 2 of the electronic light switches
that I use. 1 was 6' away from the main breaker box and controlled my
front yard water fountain, the other was +-30 feet away and controlled
my front porch lamp.


	Regards,

	jim