I have a current source controller which is used to position a valve coil. Current runs 0-.95 amps and the voltage swings about 4-13 volts accordingly. I would like to use an N-channel JFET to just act as a signal to control a relay to tell me when there is power going to the valve and when there isn't. I have the gate of the JFET connected to negative valve control, the "source" connected to ground (for the relay circuit) and the positive, and the drain going to the relay and then the positive voltage supply. I also have diodes in place to prevent damage to the semiconductor when the inductive loads discharge. All seems pretty straightfoward, but my question is regarding where the two loops meet at the source of the JFET. To correctly bias the JFET gate the positive valve connection must be connected to ground on the relay circuit. Wouldn't having that ground connected to my positive valve control mess with the behavior of my valve operation?