In order to obtain, without a cost increase, a control for maintaining the pressure of a fluid delivered from a pump at a target value, a pump control unit is equipped with a driver control unit for controlling the rotational speed of a hydraulic pump by adjusting the duty ratio of a PWM signal for driving the excitation coils of an electric motor. The pump control unit is also equipped with a signal correction circuit for converting the current flowing through the excitation coils to a voltage signal by using a shunt resistor, dividing the voltage signal by using a division ratio setting circuit, and shortening the ON-signal of the PWM signal by increasing the divided voltage. The division ratio setting circuit has a characteristic of increasing the divided voltage as the length of the ON-time of the PWM signal increases.