MOTOR DRIVE CIRCUIT

• Main Authors: AOYAMA HIROFUMI, UEDA TAKAYA
• Format: Patent
• Language: English; Japanese
• Published: 11.03.2021
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

To provide a motor drive circuit capable of suppressing output of a counter electromotive voltage to a battery connection part side of a power supply path even if the counter electromotive voltage is generated in a motor while a battery is not connected to a drive circuit of the motor.SOLUTION: A motor drive circuit comprises: a motor; a battery which supplies power to the motor; power supply wiring to which a battery voltage is supplied and which is connected to the motor; a fifth FET which connects the power supply wiring when a voltage is applied, and disconnects the power supply wiring when a voltage is not applied; a motor driver which controls driving of the motor and is capable of applying a voltage to the fifth FET; voltage application wiring which connects the motor driver with the fifth FET; and a detection circuit capable of detecting a counter electromotive voltage generated in the motor and a battery voltage of the battery connected to the power supply wiring. When the counter electromotive voltage of the motor is detected while the battery is not connected to the power supply wiring, the detection circuit cuts off the voltage applied to the fifth FET via the voltage application wiring.SELECTED DRAWING: Figure 3 【課題】モータの駆動回路にバッテリが接続されていないときにモータに逆起電圧が発生しても、逆起電圧の電力供給経路のバッテリ接続部側への出力を抑制できるモータの駆動回路を提供する。【解決手段】モータ駆動回路は、モータと、モータに電力を供給するバッテリと、バッテリ電圧が供給されモータに接続される電力供給配線と、電圧が印加されたときに電力供給配線を接続し、電圧が印加されないときに電力供給配線を分断する第５ＦＥＴと、モータの駆動を制御するとともに第５ＦＥＴに電圧を印加可能なモータドライバと、モータドライバと第５ＦＥＴとを接続する電圧印加配線と、モータに生じた逆起電圧および電力供給配線に接続されたバッテリのバッテリ電圧を検知可能な検知回路とを備え、検知回路は、電力供給配線にバッテリが接続されていないときに、モータの逆起電圧を検知すると、電圧印加配線を通じて第５ＦＥＴに印加される電圧を遮断する。【選択図】図３