Hello,

I'm in need of a little help in deciphering switch

specifications.  I need to switch a power supply of

9vdc @ 100 ma or so.  In looking through the

catalogs most switches are spec'd at AC voltages,

and the ones specified for DC seem to all have a

0.4VA @ 20 vdc specification.



The switches with the .4VA (Watt?)  spec appear

to have gold plated contacts while the AC rated

switches have silver plated ones.  Is there an issue

here with metal migration?  Also, what is the 0.4 VA

specification mean - is it the voltage drop across

the switch x current through it, or something else?

It doesn't seem quite right as these are relatively

large switches with 10 milliohm initial resistances.



I don't think that I can just blindly put in a switch

rated for AC into a DC circuit - UL probably

wouldn't like it.  Any thoughts?





Ken

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