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Switch circuit for High Voltage

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kaku88

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I would like control the High voltage switching using Op-Amp or Logic gate. The high voltage is around 550Vdc. Any solution to solve it.

Thanks
 

flatulent

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use optical isolators

It depends upon where the switch is. Your options are
(1) Use a relay with the coil energized by a NMOSFET driven with a logic gate.
(2) If the switch is relative to ground, a NMOSFET driven with a logic gate.
(3) If the switch is floating, use an optical isolator and a series pass PMOSFET. The transistor source is connected to the +high voltage and the drain to the load. The gate source has a zener across it with a resistor from the gate to ground. The zener is shunted with the output of the optical isolator. When the isolator is on, the Vgs is zero and no current flows. When the isolator is off Vgs is the zener voltage and curent flows to the load.

In all cases the MOSFET is the type in which a zero gate-source voltage causes no drain current.
 

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