| 摘要 |
PURPOSE:To enable supply of a large current to a coil of a stator of a DC motor by controlling the current by using a switch means instead of an operational amplifier, and also to prevent a flow of an overcurrent by generating a full-OFF signal at the time of switchover of the switch means. CONSTITUTION:Based on a charged voltage of a capacitor C1 charged and discharged by a discharge pulse outputted by a timing circuit 2 synchronously with a rotational position detection signal of a Hall element HE and on a reference voltage Vr, a comparator CP1 outputs a square wave signal. A control circuit 3 receives the output of the comparator CPI and an output of a Hall amplifier OP1 as inputs, turns transistors Q1 and Q2 ON alternately and controls them so that both of them be turned OFF for a prescribed time at the time of switchover thereof. Accordingly, transistors Q4 and Q3 are put in an ON state alternately inclusive of a full-OFF time at the time of switchover and electrify coils L1 and L2 in forward/backward directions by a current controlled by resistors R2 and R3, or R1 and R4, so as to rotate a rotor. |
