I am doing one design with TOPSwitch 258
Where i want voltage hystresis for turn on and off power supply.
Above 185VAC-It should on
below 170VAC-It should off

I have worked around uov/oop, but my calculation gives 6.2V zener with two resistors (Turn On-195VAC, Turn off-156AVC)

How i can achieve above hysteresis? is it possible with current devices
Turn On Voltage-185VAC
Turn off Voltage-170VAC

Deepak