VVR zener questions

[passfan]

I am assuming that the 12v 1 watt zener is providing bias to the mosfet gate ? If so , how would a 15 volt zener effect the circuit. That's as close as I have in my bins. This is the VVR circuit from Dana

[VacuumVoodoo]

It prevents Gate-Source voltage from exceeding max allowable value by clamping it at 12V. 15V Zener should be fine. You can look up VGS specs in the data sheets for that particular MOSFET.

[passfan]

Many thanks