Telemetry(Two wire transmitter)

[yasser11]

I have to design a two wire transmitter to convert a voltage signal in the range of 0-5 V into proportionate current of 4-20mA and that can drive two receivers having input resistance of 500 ohms each.Transmitter works on 24V and receiver takes power from curent loop.
what i need to know is how to design the V-I converter to achieve the above conversion.

 

[IanP]

Depending on whether you proefer to source current or sink current you will find are 2 circuits as examples for both.
For current source the formula is: I=Vz/R1
For sinking current it is: I=Vz/R2
Obviously Vz in your case will be the control voltage which, if necessary, has to be "processed" by another opamp to match the range of these v/i converters.
Regards,
IanP