<p>In a valve control apparatus for an automobile, an H-bridge type chopper main circuit 4 is operated by a control signal PWM from a microcomputer 1 to thereby drive a motor 9 for controlling a throttle valve 10. The power element current from the chopper main circuit 4 is detected by a shunt resistor 5 in the form of a voltage, and the detected voltage is amplified by an amplifier 6 and then taken into the microcomputer 1 through a sample hold circuit 12 and an A/D converter. The sample hold circuit 12 is operated in synchronism with the control signal PWM from the microcomputer 1. Further, the A/D converter is also operated in synchronism with the control signal PWM from the microcomputer 1. The motor 9 is controlled by a throttle valve opening angle command and a throttle valve opening angle signal, and further the motor 9 is controlled by a detected motor current.</p>
