Hi, i need help in this project.

I have a step up from 9 to 180v. And i need to drive a load with controlled current from 0-150 mA, the load varies from 0-1kohm.

Idea:

1-Step-up gives the Power
2-I need a current source with voltage controller. Problem how? Any ideas?
3-Drive the amps throw a H bridge, so i can +-current.
4-What to use, mosfets or bjts?

What i was trying to do was, i have the power and connect the dc/dc to the h-bridge, and putting a high voltage bjt npn connected like this base 5v throw a dac, in the emissor resistance with 25ohm, so i can have the current i need, throw the emissor and collector. Problem, the top transistors PnP, and i wanted to controll more than one bridge.

Maybe a solution with a 150v and controlled current source right after the dc/dc and then connect this to the h-bridge. Does anyone have an idea how to do this source current, providing current to the h-bridge?

 

What's the 9v source? Whenever I see someone trying to power something with "9V" I assume that they're intending to use a small rectangular 9V battery.

Ken

 

Yes forward in the project it is intended to use a battery. Now only a voltage source.

 

180V*0.15A = 23.4W = 9V*2.6A...this is assuming 100% conversion efficiency...impossible with a small 9v battery.

ken

 

I havent thought in that problem, only in the bridge. Yes it has to be bigger.

Jorge

 

The closer you can get to the 180v the better you will be. Even if it is a 12v source. But I would recommend trying for at least 24v.