Re: Garry's MMC cap failure explained.

["Tesla list" <tesla-at-xxxxxxxxxx>]

Original poster: "R.E.Burnett" <R.E.Burnett-at-newcastle.ac.uk> 


Terry,

Maybe these capacitors make use of Metallised Polypropylene instead of
using actual aluminium foil ???  I don't know if this matters that much,
but I might expect foil to withstand high peak currents better than a thin
layer of metal deposited over the dielectric.

Our Yellow Arcotronics caps (marked RS) here in the UK,  use Aluminium
foil for the end connections,  and an intermediate layer of Metallised
Polypropylene.  The internal construction is like two caps in series.

I would be interested in hearing your thoughts on this.

							-Richie,

> Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
> 
> Hi Stan,
> 
> 	I just keep looking and looking at that data sheet...  3.8 amps RMS...
> These caps I have here would be lucky to sustain 0.5 Arms...  I wonder if
> the peak amps of only 57 is the key.  Perhaps the high pulses simply ripped
> them apart and destroyed their current handling ability.

.... snip ....