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Maker Pro

Coil suppression: Which Diode and Resistor are Best?



Jan 1, 1970
Hey everyone,

I read in an article that said the value of the resistor is critical
when suppressing a solenoid coil, and the value of the diode used
wasn't important.
This doesn't sit right with me because it gives me no idea of which
Diode to use in my supressor, having never done it before. I'm also
unclear on how to determine the value of my Resistor.

To better illustrate my needs, here's the basics of my circuit:

I'm using +24VDC to power part no. Sol-52 at AllElectronics.Com.
The +24VDC comes from a wall transformer, part no. 163651 from JameCo.
The transformer's power is sent to an N-Channel Mosfet's Source
The Mosfet is rated for 100V.
My IC sends +5V to the Gate, closing the switch for only approximately
8ms, minimum 5ms.
When Gate is charged, the +24VDC travels to the Solenoid coil.

Given all the info, what type of Diode should I use, what part number
should I look into, and what equation should I use to determine the
rating of my Resistor?