Re: Maxwell 31159 cap on eBay

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

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



If a HV pulse cap is not rated for high % voltage reversals, there is
significant corona formation at the edge of the foils.  This corona and
surface tracking begin to heat up the local dielectric area (di/dt) and will
eventually produce enough heat to begin melting through the dielectric.

Dielectric breakdown at the edge of the foil is the number one killer of HV
pulse duty caps (according to Maxwell Sr. Engineer Bob Cooper).  Second on
the list are small voids in the dielectric material, which also produce
corona in the voids due to the different dielectric constant in the void
material, and, again, leading to local intense heating effects that damage
the dielectric.

Pulse caps not rated for high voltage reversals literally "can't take the
heat".

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: Friday, June 18, 2004 6:34 PM
Subject: Re: Maxwell 31159 cap on eBay


 > Original poster: Ed Phillips <evp-at-pacbell-dot-net>
 >
 > "It's a low rep rate cap with 20% max voltage reversal.  Definitely not
 > the
 > best for TC duty.
 >
 > Dr. Resonance"
 >
 > It's a non-polarized capacitor, so what is the significance of the
 > voltage reversal spec?  Low rep rate might be related to internal
 > heating, but I don't understand the reverse voltage part.
 >
 > Ed
 >
 >
 >