Converting Mechanical Pot Control (50 k ohms) to 4-20 mA Signal control

The easiest solution is to buy what is called a "signal converter" (or sometimes called a signal conditioner), a small device that will accept your 4-20ma current loop signal and convert it to a variable voltage. The input pot that you have is actually providing a variable input voltage signal, either 0-5V or 0-10VDC, which the pot is lowering by increasing the resistance. First thing you will need to do is determine which one it is using, then you can select a signal converter.

Here's some more info on that idea.

http://focus.ti.com/lit/an/sboa023/sboa023.pdf

Good luck!

From Tim Hawley Master Mech.

Hello Guest,

Disconnect one wire from the current mechanical pot and check the voltage across the two (2) wire connections. If it is 12 Volts, you are currently using a measuring range of 0-12 volts dc or 0 to .24 mAmps. E/R=I

Some converters have an adjustable potentiometer on the board for zero adjustment.

Make sure the wires you use are twisted for good isolated signal transmission.

Find a converter interface board to convert current to voltage and use an isolated power supply that is very stable. See last link for interface boards. The first 2 links are FYI only.

Check these links for more details,

http://celesco.com/faq/420.htm

http://zone.ni.com/devzone/cda/tut/p/id/6940

Let me know if you need more help.

Best Regards,

Tim

i am review the various recommendations. I will keep you posted.

thank you for your responses!