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Arfa Daily

"Maynard A. Philbrook Jr." wrote in message
...
In article ,
says...

I have a 12V SPST cube relay in my junque box. The diagram molded into
the
relay¹s housing includes a component connected in parallel with the coil
which looks suspiciously like a resistor.

It¹s not a back-emf diode: I connected the relay coil using both
polarities
(using a current-limited power supply) and the same current draw is
measured.

What is the purpose of this resistor?

Thanks,
Dave

more than likely a snubber network, they normally have a
resistor and cap in a single component..

Many times, they simply show it as a R across the coil because
it's in series with a cap.

Looking at a data sheet for an Omron automotive relay that shows this
'unknown device' across the coil, it appears to detail it in the specs as
"1.1k suppression". It gives the coil resistance with and without this
included. If there was any series C involved, then the coil resistance would
not change with or without the device. This leads me to believe that it is
nothing more or less than a simple current dumping resistor with a value of
1.1k

Arfa

http://en.wikipedia.org/wiki/Snubber