[ARC5] Disc Capacitors

[Bill Cromwell]

On Sun, 2013-03-03 at 09:50 -0500, wb3fau55 at neo.rr.com wrote:
> Don't use  diameter as a rule of thumb  to determine unknown voltage rating.  There  have been
> some  pretty bad dielectric materials used in past.  Ceramics and epoxies are very good.
> Some plastics from  years ago not too good.  Unless it is  marked as  rated  for 500v, I would
> not use it on high voltage.  73 Russ.
> ---- Robert  Eleazer <releazer at earthlink.net> wrote: 
> > I have some .01 mfd caps that are not marked as to max voltage capability.  They are pretty good size, at least a half inch in diameter, maybe more.  I also have a bunch of .01 mfd caps that are marked "50V" and are no more than 3/16 inch in diameter.   I need some that are good for at least 500V.
> > 
> > Does anyone know a good rule of thumb for diameter versus voltage relative to disk caps?  Bigger means higher voltage; that follows logically, since you need more insulation, but what kind of a estimate can we make based on size?
> > 
> > Thanks.
> > 
> > Wayne     

Hi,

I have a drawer full of disc caps that do not have voltage ratings on
them. I consider the manufacturers being too ashamed of their products
to put their name or voltage rating on them. I will use them in 12 volt
solid state circuits and save the real ones for my tube circuits at
higher voltages. properly rated and *marked* caps are available at very
reasonable prices from multiple online sources.

73,

Bill  KU8H