PURPOSE: To enable free setting of wiper drive circuit in wide range by functioning a switching means for driving a bridge circuit continually on the basis of an output signal from a comparator circuit.
CONSTITUTION: A switching means 7 for driving a bridge circuit is provided between main power source switch 6 and a bridge circuit 2 while counter-electromotive force of D.C. motor 1 provided from the bridge circuit 2 is amplified differentially by a differential amplifier 10. An operating amplifier 13 will add an input signal from said amplifier 10 and a speed command input signal from a rotary speed setting means 12 to bring D.C. motor 1 into setting speed. When the speed of D.C. motor 1 is higher than the setting level, a signal for rotating said 1 is higher than the setting level, a signal for rotating said motor 1 with low speed is produced while when it is higher than the setting level, a signal for rotating said motor 1 with high speed is produced to bring said motor into setting speed.
TAKAHASHI YOSHITERU
NOZAKI MASAHARU
SHIKO GIKEN KK
| JPS5867543A | 1983-04-22 |
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