Suppose you have a potentiometer that could vary the voltage from 0-10V. For simulating the signal from field instruments, it needs to be converted to 2-20mA. I also plan to use a cheap little LED voltmeter module to display the current output.

I have made a little circuit using 2 op-amps. Both are LM741. The point where the load will be connected is R2. This is typically between 100 -500 ohms, depending on various analog input modules for PLCs and also the additional resistance of IS barriers.

This simulates well on LTSpice. My experimental file is attached.

 

Hi Raj,
Welcome to AAC.
How will you drive the 2mA > 20mA through R1, 500R.?
The 741 OPA is very old and has a poor specification, do you have a more modern OPA available.?
E

Update.
Is this a drawing error?

 

"it works in simulation"

 

0-10V to 0-20mA circuit. Can it be improved? it needs to be converted to 2-20mA.

Hi Raj,
The circuit can be simplified.
If you use a modern OPA it will be possible to get Vout closer to 0V
E

 

Suppose you have a potentiometer that could vary the voltage from 0-10V. For simulating the signal from field instruments, it needs to be converted to 2-20mA. I also plan to use a cheap little LED voltmeter module to display the current output.

I have made a little circuit using 2 op-amps. Both are LM741. The point where the load will be connected is R2. This is typically between 100 -500 ohms, depending on various analog input modules for PLCs and also the additional resistance of IS barriers.

This simulates well on LTSpice. My experimental file is attached.

Actually, this is a terrible idea as the current in the feedback path cannot be used in any external circuit that shares a common ground. See my newer post that gives a much better design.

 

Hi Raj,
The circuit can be simplified.
If you use a modern OPA it will be possible to get Vout closer to 0V
E
View attachment 340008

Thank you, this is a better design.