Re: Bleeder resistor spacing warning!

["Garry F." <garryfre-at-xxxxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

Mine that blew were on the underside of a standard perfboard as well. The
cap swelled and opening it up showed gross arching accross one edge of the
aluminum melting the dialectric like a piece of plastic in a toaster.

I think I was told a quarter of an inch. I think a simpler way would be to
put some poly between the resisters and the perfboard.

----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, November 21, 2000 7:48 PM
Subject: Re: Bleeder resistor spacing warning!


> Original poster: "Travis Tabbal" <bigboss-at-xmission-dot-com>
>
>
> How much space? Mine were on the underside of a standard perfboard. I
> inspected the caps and they seem fine. There was some brown residue on
> them from the blown resistors, but they did not appear to be damaged.
> Replacing the resistors fixed the problem. Watching them blow, it did
> not appear to arc to the cap body in my case though.
>
> Travis
>
>
>
> > Original poster: Terry Fritz <twftesla-at-uswest-dot-net>
> >
> > Hi All,
> >
> > There have been a few cases where bleeder resistors have been
> placed
> > directly against the bodies of MMC caps and have managed to arc
> through the
> > thin capacitor casing.  The outer foil layer of the caps can easily
> be at
> > the opposite potential of the bleeder resistor and there can easily
> be
> > corona or electrical breakdown.
> >
> > One should space the resistors away from the caps or put some
> additional
> > insulation between the resistors and the cap body.  This problem
> seems to
> > especially afflict the tubular style wrapped resistors.
> >
> > Cheers,
> >
> > Terry
> >
> >
> >
>
>
>