| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce in size and to improve a calculating accuracy of a load drive circuit for controlling so that a mean voltage of a load for driving by pulse width modulated DC current becomes proportional to the duty of a pulse width modulated command signal pulse. <P>SOLUTION: A command value arithmetic circuit, a soft start arithmetic circuit, an error arithmetic circuit, an amount-of-operation arithmetic circuit and a PWM signal generator of essential parts of the load drive circuit are formed of digital circuits. Further, the drive circuit includes a gate signal generating circuit, a differential amplifying circuit for detecting a load voltage, a low-pass filter, an A/D converting circuit and a switching element for switching DC load current. <P>COPYRIGHT: (C)2004,JPO |
