Hi Guys, I am in bit of a spot here. I do programming for hydraulic presses. If anyone is unfamiliar this entails programming PLCs to automate a press or a machine. The problem I face is that the output current from the PLC is between 4mA - 20mA. I have a proportional valve that needs a signal between 4mA - 800mA. Basically it is off at 4mA and 100% open at 800mA. I can't find a circuit that might be able to amplify the output I am getting from the PLC so that I can get the proper functionality from the proportional valve. Anything that can linearly change the output current from the PLC and obviously max out at 800mA when the output from the PLC is 20mA.