Re: Magnifier Primary Capacitors - EQUIDRIVE vs. STANDARD

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

Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> 


Actually, Terry, you were correct.

Cooper told me they had incredible headaches with metallized type caps in
air.  They would discharge one section and by doing this, it would actually
charge up another section.  A lot of crazy things were happening in air.

In oil, the circulating currents neutralize the cap potentials.  This is one
reason why most all their HV caps are in oil.  Also, of course, the edge of
foil tracking currents are much less.

He said there are 3 different reasons that can produce these strange charges
in air:

(1) Unequal cap values.  They match their caps at 0.5% or better.  More
specifically the dielectric leakage in individual caps is important.  It's
not good in metalized foil caps.

(2) Dielectric polarization.  Even partial polarization produces
displacement currents and unequal charge distribution.

Most important factor (3) In oil, the small circulating currents equalize
and discharge the caps.  This is due to the dielectric hysteresis effects in
energy discharge caps.

Bob said most of their HV filter caps contain internal discharge resistors.
He said the high Q energy discharge caps do not because of the oil currents
and hysteresis effects.

Safety first:  In conclusion, we should continue to use bleeder resistors
across all metalized foils caps operated in air.  I always use pcs in
series, 4.7 megOhm each.  Each resistor has 1/2 watt rating.  Also, even
after discharging each section, Cooper warns, always handle them with rubber
gloves if you are not using bleeder resistors!!!

Dr. Resonance

Resonance Research Corporation
E11870 Shadylane Rd.
Baraboo   WI   53913
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, January 13, 2004 6:04 PM
Subject: Re: Magnifier Primary Capacitors - EQUIDRIVE vs. STANDARD


 > Original poster: Terry Fritz <teslalist-at-twfpowerelectronics-dot-com>
 >
 > Hi D.C.,
 >
 > It will be interesting to here what they say!  Unlike MMCs, these caps
will
 > be damaged if residual or unbalanced charges happen to cause a breakdown
in
 > a cell.  My guess is, the oil is so very slightly conductive.
 >
 > Of course, this would not be the 20th time I have been proven wrong ;-))
 >
 > Cheers,
 >
 >          Terry
 >
 >
 > At 02:19 PM 1/13/2004, you wrote:
 >
 > >Terry has encountered this phenomonea with MMC caps which is quite
unusual
 > >because Maxwell and PCI caps both use a series of small caps connected in
 > >series inside the box --- I know Beau Meskin, when I visited the PCI
factory
 > >in Chicago, showed me the interior of a 0.1 uF 30 kV cap and it has 22
 > >separate small caps all series connected.  This construction would
simulate
 > >the series connected MMC technique that we are all presently using, so
why
 > >would there be any difference?  Unless, as Dave Sharpe noted, there are
some
 > >different effects going on with the equi-drive system.
 > >
 > >I plan on calling my friends Bob Cooper and Randy Hartsock who are the
 > >senior design engineers at Maxwell and pose this question to them.
Perhaps
 > >we can get to the bottom of this mystery.
 > >
 > >Dr. Resonance
 > >
 > >Resonance Research Corporation
 > >E11870 Shadylane Rd.
 > >Baraboo   WI   53913
 > > >
 >
 >
 >