"John E." wrote in message
obal.net...
Ben Miller sez:

You can't just guess at this. As sue suggested, you need to look at the
circuitry and figure out what that diode function is. ...

OK, here goes:
German-made paper-handling machine, c. 1989. Circuit activates solenoid,
taking several inputs from other sensors, signals, etc.

Anode of unknown diode is to ground, cathode to drain of BUZ72 MOSFET. 1uF
cap also from drain to ground. Drain connects to solenoid. Drive voltage
is
42vdc.

Thanks,
--
John English


Not then, I would suggest, a 4.7v zener ... Sounds like it's just a
flywheeling diode and a 1N4007 would do the job just fine. Does the FET
source go to ground ? Many power MOSFETS have a diode internally in that
orientation across from the source to the drain. It gets there as an
integral side effect of the manufacturing process.

Arfa