| 摘要 |
PURPOSE:To perform low-cost data transmission by detecting locations, where data are existent, and synchronism on the basis of data as transmitted to generate a synchronous timing signal. CONSTITUTION:When data is transmitted from an indoor unit to an outdoor unit in synchronism with a power supply 1, for example, in a positive semi- synchronism, a first signal detecting unit 7 counts time from a beginning of data as transmitted to a beginning of next data to detect synchronism of the data as transmitted (synchronism of power supply). Subsequently, in the case of power frequency of 50Hz, synchronism of power supply is 20 millisecond, and central locations where data are existent correspond to 5 millisecond, 25 millisecond, 45 millisecond,... measured from a beginning of an initial data. Accordingly, a synchronous timing signal of synchronism of 20 millisecond is generated to correspond to central locations where data are existent. On the basis of the synchronous timing, the outdoor unit takes in the data as transmitted. Accordingly, it is possible to perform inexpensive data transmission. |
