In the Documentation for the MC4x family of controllers - it says in many places to use diodes for external coil suppression, for example when driving a relay with the Digital Out HS driver from the MC4x.
A relay that I have specific to my application requires (highly recommends) the use of varistor coil suppression, which is less "harsh" on the relay device during transients. The specification requests a clamping voltage of 3x the coil voltage, i.e. 36Vdc for a 12Vdc relay coil.
Are there any adverse affects of using a varistor instead of a diode for coil suppression?
Perhaps this could be also compatible with the hardware design of the MC4x series of controllers?
(Hint: I already have tested this configuration on my system to many thousands of cycles under load with no discernible affect on system operation or relay operation)
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