Hi, I am trying to build up a circuit, and the source should be a sinusoidal current source. From my dspace board, I can send to the breadboard a voltage signal only. How can I manipulate the voltage signal - which can be set to any value between +-8 V - to obtain a current source with a magnitude around 0.2mA?

 

How about the good old trusty transformer? I wouldn't think it would be hard to find a suitable one. It'll give you that good sine wave, using ordinary 60 or 50Hz wall power.

 

Exactly what are you trying to do with this signal?

 

use two transistors see attached.
Picbuster