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Old October 29th 09, 04:35 PM posted to rec.aviation.homebuilt
Brian Whatcott
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Posts: 915
Default Master contactor question

jan olieslagers wrote:
schreef:
The large ST35 and ST36 are the only continuous duty units rated at
14-16 ohms. All the smaller ones are 16-25 ohms.


Isn't there a difference in resistance betwen the active state and the
passive? I feel some people have determined coil resistance by measuring
with a cheapo multimemer - this uses a small battery, the ensueing
measurement will reflect the inactive state. Better would be to activate
with a battery (or better still, a stable 12V reference) and measure the
current.



Yes there is a difference in resistance with temperature for most metals.

But I certainly hope you couldn't spot the difference with any ease.
This is not a filament whose resistance can double (or more) at
operating temp.

Brian W