| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an AC motor control device that can reduce a quantized error accompanied by the A-D conversion of a voltage that corresponds to a motor current of an AC motor, and can improve reliability. <P>SOLUTION: The AC motor control device comprises: an inverter circuit; a current detection circuit; and a microcomputer containing an A-D conversion circuit. The current detection circuit comprises: a current detection resistor; a differential amplification circuit that amplifies a voltage of the voltage detection resistor wider than a voltage range to which the A-D conversion circuit can input a voltage, and to a voltage of single polarity; and a voltage conversion circuit that converts an output voltage of the differential amplification circuit to a voltage range to which the A-D conversion circuit can input a voltage. By this, the output voltage range of the current detection circuit can be widened, and the quantized error accompanied by the A-D conversion is reduced, thus improving the reliability. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
