| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To solve the problem that, when transferring information about the temperature of a temperature sensing diode SD that senses the temperature of an inverter to a microcomputer 20, if a port comprising a timer function or an A/D conversion function of the microcomputer 20 is used, its resources may be reduced. <P>SOLUTION: A signal frequency-modulated by a frequency modulation circuit 34 based on an output voltage of the temperature sensing diode SD is fetched into a photocoupler 36. An output of the photocoupler 36 is fetched into the microcomputer 20. In the microcomputer 20, processing is performed by hardware for recognizing a logic "H" when an output voltage of the photocoupler 36 is equal to or higher than a threshold voltage or for recognizing a logic "L" if it is lower than the threshold voltage. At the same time, demodulation processing for temperature information based on a period of time of the logic "H" or a period of time of the logic "L" is performed as software processing. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
