i searched for FET with vgs max 110v or 230v not able to find. anything available

 

I don't think you will find any.
If the switching doesn't need to very fast you might use a resistor connected to the high voltage and a zener across the gate and source to limit the voltage.

 

i searched for FET with vgs max 110v or 230v not able to find. anything available

Most MOSFETs have gate oxide breakdown of usually not more than 20 -30V

 

i searched for FET with vgs max 110v or 230v not able to find. anything available

I think you might mean Vds, not Vgs. And you may not find them in that voltage range. You don't say if that is the voltage you want to switch, but if it is, like most things having to do with electronics you need to have a higher rating on them than just the voltage your working with. If you want the component to live.

 

I think you might mean Vds, not Vgs. And you may not find them in that voltage range. You don't say if that is the voltage you want to switch, but if it is, like most things having to do with electronics you need to have a higher rating on them than just the voltage your working with. If you want the component to live.

In a flyback converter running from 230V - the MOSFET is likely to be rated at least 600V, some equipment manufacturers play it safe and specify 900V parts. 800V is more or less average.

Presumably; its about half that in 110V equipment.

230V push-pull converters have at least 400V MOSFETS (in CFLs etc). Proper kit has at least 500V rated parts.

 

https://www.fairchildsemi.com/datasheets/FC/FCH041N60F.pdf

 

In a flyback converter running from 230V - the MOSFET is likely to be rated at least 600V, some equipment manufacturers play it safe and specify 900V parts. 800V is more or less average.

Presumably; its about half that in 110V equipment.

230V push-pull converters have at least 400V MOSFETS (in CFLs etc). Proper kit has at least 500V rated parts.

That's what I was saying, isn't it?

 

That's what I was saying, isn't it?

Not in so many words that I could find.

 

You don't say if that is the voltage you want to switch, but if it is, like most things having to do with electronics you need to have a higher rating on them than just the voltage your working with. If you want the component to live.

Since he never answered or came back I gave a general way of choosing a voltage. And since many mosfet circuits need a driver, how are the voltages you quoted driven? Since most drivers are only rated at 500 to 600 Volts. Not trying to start a fight just asking a question.