Abstract: A stopping noise reduction circuit for a start motor comprises a battery generating a power supply to drive the start motor, a key switch for controlling an on/off of the power supply, a solenoid having a permanent magnet, P and H coils, and a movement contact to drive the start motor, and further comprises a B1 terminal grounded inside the solenoid, an M1 terminal connected to an M terminal of the start motor, and a resistor coupled with the B1 or M1 terminal. In the stopping noise reduction circuit, upon an off condition of the key switch, the movement contact of the solenoid is connected to the B1 and M1 terminals such that more induced current than an induced current flowing into the P and H coils, in a current induced by a rotator of the start motor, flows to ground via the resistor within a short flow time.

Abstract: The starter motor for a vehicle is capable of achieving a minimum and optimum size of a magnet switch and a starter motor in such a manner that a lever ratio R and an air gap A are improved in a range satisfying a designated moving distance P of a pinion. There is provided an improved starter motor for a vehicle characterized in that an air gap A is set below 8 mm, and a lever ratio R is adjusted above 1.67, whereby a moving distance P of the pinion is about 13 mm. In addition, there is provided an improved starter motor for a vehicle characterized in that the multiplication of air gap A and lever ratio R is below 14 mm, whereby a moving distance P of the pinion is about 13 mm.