prprog
Member
Fet as voltage control resistance
Please see the attach circuit. (thanks to NSKL for the pdf document on the subject) . I try it using it as a substitute for the resistance/pot on my PC game port (Joystick) but cannot make it work. I apply voltage to the gate that are less (1 , 2 volts) but the resistance does not change. Do I need this gate voltages to be negative? (the PDF document indicates negative voltages). if this is correct, how do I generate negative voltage from +5V and GND.? Thanks a lot.
Please see the attach circuit. (thanks to NSKL for the pdf document on the subject) . I try it using it as a substitute for the resistance/pot on my PC game port (Joystick) but cannot make it work. I apply voltage to the gate that are less (1 , 2 volts) but the resistance does not change. Do I need this gate voltages to be negative? (the PDF document indicates negative voltages). if this is correct, how do I generate negative voltage from +5V and GND.? Thanks a lot.