Output pin on low is opening MOSFET gate

Other Hardware Motors, Mechanics, Power and CNC
21

Thanks. Is there a name to the effect? I cant explain why theres only very little current flowing. Lets say in theory i used different wire for the blue arrow as the yellow in your picture and the wire for the blue got a higher resistance. It would even make sense to use different wire there.

22

  • A MOSFET is what we call a voltage controlled device.
    The gate is basically a capacitor to GND.

  • A MOSFET has essentially infinite gate resistance, hence no DC current flows through the gate.

  • Current out of the plus battery terminal returns to the negative battery terminal, not the Arduino.

  • The ground wire from the negative battery to the Arduino has zero battery current flowing, it only has Arduino 5v current flowing, if any.

23
  • Both the positive and negative battery wires need to be very low resistance, probably in the milli ohm range.
    We do not want significant voltage drop across these wires when the MOSFET is turned ON.