20v dc convert to a ajustable 4 to 20 ma signal

Hi, i need to convert a 20v dc + to a 4 t0 20 mA variable signal
can you help please
thank you
Collin

Collin,

How do you want to vary the 4-20mA level? Are you trying to create a 4-20mA output transducer? Or, is this to be a test signal to check a 4-20mA receiving device?

Ken

Do you want to convert 0-20VCD to 4-20ma? I just came up with the reverse circuit, a 4-20ma to 0-5VDC for another thread.

Hi bill. the project is to test controllers on the air compressors as a simulator. the origenal layout is a 20v dc + (one wire) running to an air
pressure transducer. this converts to a 0 to 20 mA signal. (one wire return) the idea is to simulate the air transducers. i want to use the 20v + from the controller and vary the 4 to 20 mA signal ( if possible). the controller converts the 4 to 20 mA signal to airpressure reading.as a result i can test the controllers alarm and cut out settings.

Here is an adjustable constant current source, along with a DVM, should serve your purpose.

Ken

KMoffett said:

Here is an adjustable constant current source, along with a DVM, should serve your purpose.

Ken

Click to expand...

just the thing i need to test water pump pressure PLC, need 4-20 ma for setting and testing program. thanks