You have one data point: normal current. Now stall the motor and see what that's. Now you have lower and upper bounds to select a fuse value.The motor I am driving is a gearhead motor, and has surprising power, especially considering that it draws only 320mA at 12V under full load. I want to fuse the entire circuit, and am thinking a 1/2A fuse would be sufficient.
Initially, the power supply will be a wall wart, but longer term, it will be a deep cycle marine battery. I have limit switches that should prevent the motor from stalling, but just in case, I want to add a fuse. I think I'll start small (.5A) and see if that causes a problem; I can always increase the fuse amperage.It stalls at 4.2 amps, so that will be your start surge. How long the start surge lasts will determine your fuse size. Obviously not more than a 4.2 amp fuse or it will never blow. Just guessing, something in the 1A or 2A range, slow, should work. Can your power supply provide enough current to blow the fuse?
by Jake Hertz
by Jake Hertz
by Jake Hertz
by Duane Benson