Patent attributes
A motor overcurrent protection device connectable to a motor. The motor has a rotary shaft and a controlling port. The motor overcurrent protection device includes a sensing unit, a driving unit and a controlling unit. The sensing unit includes a magnetic block arranged on a circumference of the rotary shaft and a Hall device positioned beside the rotary shaft. The magnetic block is rotatable along with the rotary shaft to be instantaneously aligned with the Hall device. The driving unit is electrically connected with the controlling port of the motor. The controlling unit is electrically connected with the sensing unit and the driving unit. When the motor operates, each time the magnetic block is aligned with the Hall device, the Hall device outputs a pulse signal which is stored in the controller of the controlling unit. All the pulse signals are summed up in a preset sensing time of the controller. In the case that the sum does not exceed a standard rotational speed value, the controlling unit via the driving unit will stop the motor from operating so as to protect the motor from malfunctioning due to rising of current.