Patent ID: 6998815

Claim:
A motor drive control apparatus comprising: a motor; a power supply; a control circuit; a first current detector; a first switching element, a first main electrode of which is connected to the power supply and a second main electrode of which is connected to one end of the motor, a first control voltage being supplied from the control circuit to a control electrode of the first switching element; and a second switching element, a first main electrode of which is connected to another end of the motor and a second main electrode of which is connected to a reference voltage point via the first current detector, a second control voltage being supplied from the control circuit to a control electrode of the second switching element, wherein the first current detector generates a first detection voltage indicating a first current flowing through the motor in one direction, wherein the first detection voltage and a first specified input voltage are applied to the control circuit, and wherein the control circuit generates a PWM voltage as one of the first control voltage and the second control voltage and generates an ON voltage, which is turned on at least during an ON period of the PWM voltage, as the other voltage of the first control voltage and the second control voltage, if the first detection voltage is lower than or equal to the first specified input voltage, and the control circuit generates an OFF voltage as the first control voltage and generates the PWM voltage as the second control voltage, if the first detection voltage is higher than the first specified input voltage, to adjust a pulse duty of the PWM voltage in accordance with a difference voltage between the first detection voltage and the first specified input voltage and to control the current flowing through the motor so as to be equal to a target current.