| 摘要 |
PROBLEM TO BE SOLVED: To prevent a harmonic, which stems from a duty signal, from steadily degrading a receiving state.SOLUTION: A duty control unit includes a switching circuit 12 (output circuit) and microcomputer 11 (target designation means) which are included in an air conditioning ECU 10. The switching circuit 12 outputs a duty signal which commands conduction or discontinuity of electricity to a solenoid coil 21 (actuator) of a control valve included in an onboard compressor. The microcomputer 11 designates a target duty ratio for conduction so that a mean value of a conducting current will be a target value. The switching circuit 12 adjusts the length of the cycle of the conduction and discontinuity of electricity so as to designate a duty signal dependent on the target duty ratio. |
