> The 270 Ohms across the g-s zeners may not be needed - and
> account needs to be taken of the fact that it also forms a divider
> with the driver to gate resistors usually specified

Yes. If the drive resistor is relatively large (eg 100R) then the voltage
loss is significant. Would reduce 12V drive to ~ 9V. At 10 ohms the
reduction would be to ~ 11.5V. The gate pull-down somewhat helps
the FET turn off, but may be overshadowed by the pull-down effect
of the drive transistor, in which case it may be excess to requirements

Joe


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