I would like to use a MOSFET to allow a microcontroller to connect and disconnect the power to a motor using the circuit shown below:
The current drawn by the motor will change as the motor moves, varying from 100mA to 300mA. A PTC fuse will be put in line with the motor to prevent it drawing too much current.
Am I correct in saying the MOSFET will act as a switch in saturation region so long as the drain to source voltage is high enough (for a given gate to source voltage)? So for the below example, for a VGS of 6V, the MOSFET will be in saturation so long as the drain to source voltage is above 0.21V?
If this is correct, am I also correct in saying the drain to source current will not decrease below the IDS stated on the above graph? For example using the below graph, if VGS=6V and VDS=8V(therefore the MOSFET is in saturation), then IDS will be 7.5A? Therefore it will try to force 7.5A through the motor? Or is it the case that the MOSFET can allow up to 7.5A to flow but if the motor only draws 300mA, 500mA, 1A etc, the MOSFET will allow this?