| 摘要 |
PROBLEM TO BE SOLVED: To correctly identify a gas leak linkage signal without incorrectly identifying it as a fire linkage signal even if the gas leak linkage signal and the fire linkage signal are transmitted on the same signal line. SOLUTION: Based on the divided count of a zero-cross detection signal of a commercial alternating-current power supply, a timing generator 4 generates a plurality of timing signals, which have different phases and a specified pulse width, and are repeated in a specified cycle, corresponding to gas leak types. When detecting gas leak, a linkage signal output part 5 outputs a timing signal corresponding to types to a signal line connected with other alarm devices as a gas leak linkage signal. When receiving a linkage signal from another alarm device, the linkage signal output part 5 resets the timing generator 4, and then synchronizes the self timing signal with the timing signal of the other alarm device to which the linkage signal is transmitted. A linkage signal receiving and judging part 7 judges a type of the received gas leak linkage signal synchronized with the timing signal and alarms gas leak detection by the other alarm device. COPYRIGHT: (C)2004,JPO&NCIPI
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