Hi, I would like to make a 4 to 20 ma generator to test the analog input on a plc. As always I have been working on this for a while before I come running for help to the forum and am still at a loss. I can generate a 0 to 5 volt dc signal with a simple pot but can not get the mA to co-relate. I also have researched and know that a 250 resistor will convert the 0 to 5 to 4 to 20.but I can't make it work and to top it off I blew the fuses in my fluke and it cost 80 bucks for new ones. I would like to display the settings on an lcd so I would like to use a pic and pic basic. I can handle the lcd stuff but I just need a direction. As always I will post the results when I get it working.
Thanks again great forum,
Snap