I want to use 4-20MA output circuit which have a current constant with varying load between 0 to 500 ohm

 

Any one halp me in this regard?

 

Hello,

Take a look at this circuit:
http://www.piclist.com/techref/microchip/aout.htm

Use a powersupply between 12 and 15 Volts.

Greetings,
Bertus