hi babar,

I think you should use some kinda Opamp for doing this. I remember I saw a similar circuit in a book. I have this at my home. I will try to send you some info as soon as I get it.

Meanwhile I sent you two books via one of my friend. His Karachi phone is 5651835. His name is Aamir Umer. I could not send the book with Mr.Tahir Chowdhry.

KIT (keep in touch)

Rauf