I'm working on a project where I need to be able to implement a switch capable of turning ON/OFF current flow in a high voltage circuit using a very small base voltage.

The current flow that I need to control will be between 500V-2000V (~10-15mA current) and the base voltage that I would like to control that flow with will be only 3.3V (10-20mA current).

I've come across two components I could use as switches - an NPN transistor or a solid state relay. Problem is, most of these seem to only be for low voltage applications. And in the case of NPN, I can't find one that has acceptable emitter-base and collector-base voltage limits. Can you recommend or point me to a source for components that might work for this project?

 

An IGBT shall be suitable for your application, however, it needs 15V to its gate to turn on.

Are you going to drive it by a microcontroller?

 

Yes, that is the plan right now. Any thoughts on a way to get around the 15V turn on voltage at the gate? Is the gate voltage limited or power limited (where the combination of current/voltage matters)? I'll be dealing with DC so I guess that rules out a transformer.

 

Yes, that is the plan right now. Any thoughts on a way to get around the 15V turn on voltage at the gate? Is the gate voltage limited or power limited (where the combination of current/voltage matters)? I'll be dealing with DC so I guess that rules out a transformer.

I guess you have a 3.3V microcontroller.

You need to provide a 15V DC power supply by some means. Then I advice you to use an IGBT gate driver to drive the IGBT.

 

most definately some form of opto coupled circuit would be of use here. DC isolation