Bill,
A lot of small relays especially with bifurcated contacts (2 contacts
side by side with a small amount of give to each one) also have a
minuscule amount of wiping between the contacts upon closure. The
combination of gold clad silver and this wiping allows the relay specs
to allow use in circuits of 1 uA or less although testing is usually
done at the 10 uA level. My experience is with non-RF applications at
current levels below 1uA with no issues of contact oxidation.
73,
Larry, W0QE
Bill Fuqua wrote:
> Here is a problem I have with relay specifications. Usually, for weak
> signal applications we use gold plated contact switches and relays. Since
> most relays or switches are normally exposed to air, oxidation can form and
> weak signals can't always be conducted between them. Naturally in a vacuum
> any good conductor can be used in the contacts because oxidation can't
> form with our air. Years ago it was suggested that as long as the relay had
> a set of contacts that rub as they close, this friction would break thru
> any crusty oxidation and clean the contacts. But, I can't see that working
> 100% of the time.
>
> 73
> Bill wa4lav
>
>
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