PURPOSE: To eliminate the ununiformity in the characteristics of a step motor by a method wherein a demagnetizing pulse having the current direction opposite to that of a large output pulse and having a narrow width is impressed on the step motor after the large output pulse is impressed on the motor.
CONSTITUTION: A step motor constituted by a stator, a rotor and a coil is provided, and the rotation and non-rotation of the rotor are determined by converting a value of a detection current made to flow through the coil into the fall of a voltage of a detection resistance. On the occasion, after a large output pulse Pi1 is impressed on the step motor, a demagnetizing pulse Pe having the current direction opposite to that of the pulse Pi1 and having a narrow width is impressed on the motor, and thereafter, the detection resistance is set selectively.
KITANO MASUO
ITOU JIROU
SUWA SEIKOSHA KK
| JPS531144A | 1978-01-07 |