I'm using an Arduino as a valve controller for this pneumatic shifting system I'm making, and the operation is pretty simple, power is sent to the valve through an N-fet, and a signal is sent from an Arduino pin to the gate.
I noticed that when I used a 18ohm resistor, the valve would stutter a lot, then when I kept using bigger resistors, eventually moving to 2.2K, the circuit functioned as intended. Can someone explain to me physically why this is? I also noticed that the voltage across the drain and source didn't take as much time to ramp up and ramp down.
I'm trying to set this system up so I press a button on the wheel and it shifts, so on my test bench (if you could even call it that), I have one wire coming out of 5V on the arduino and one coming out of a digital pin so touching them together simulates a SPST switch. whithout any resistance, the valve just stuttered and nothing worked correctly, when I put a resistance of 18K ohm in line with the two wires, there still was some stuttering. So my second question is am I doing this right and just have to use a really high resistance between the 5V and signal pins?
I've got the arduino and Drain/Source lines connected to a car battery for power.