Ron Tebo wrote:
>
> Tom Yang wrote:
snip
> Tom:
>
> (Where are all those electrical engineers when you need them!)
> I have always been curious about this too, since my understanding of the
Ron
I was also waiting for someone who knows more that I do about this to fill in
here, in
the meantime I will take a shot. This is only what I have inferred from the
applications:
In high voltage applications dielectric grease is non conductive and displaces
dirt,
water, and crud that can collective. It also helps to prevent corrosion of
metal
contacts and, as Ron points out, is easily cut through by the contacts. "Crud"
(highly scientific term) can be conductive and when in the presence of high
voltage
offers another electrical path. Dielectric grease seals this stuff out.
In low voltage applications this can also help prevent the discharge of
batteries.
Lead acid batteries tend to produce a film (even the so called sealed bateries)
and
this film is definately conductive. I suppose that the use of dielectric grease
here
will help prevent a continual drain on the batteries. Probably not as
important on a
car battery where it is charged often by running the engine.
Tom, I don't know if this grease would be helpful in a switch. A good switch
design
has a minute amount of rubbing between the contacts with every actuation
(called
contact wipe). This is intended to wipe away oxides and ensure good electrical
conductivity. If you have access to the switch contacts you might try some and
see if
it helps. Maybe the conatct force is enough to push through the grease, maybe
not. A
better product for this is probably a liquid contact cleaner. Radio Shack
probably
sells it, it might be called tuner cleaner (goes back to the days when TV
tuners were
mechanical devices with lots of contacts) . Spray a tiny amount on and do a
little
wiping. It removes oxides and offers some level of protection against future
oxidation.
-Roger
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