| 摘要 |
Apparatus for conserving the alarm-state power supplied to a plurality of light emitting devices associated with respective terminal units in a fire alarm system or the like comprises a transmission line having a plurality of terminal units connected thereto. Each of the terminal units has comparison means for determining whether a received address signal coincides with an identification address stored in the terminal unit, the comparison means producing an output signal responsive to coincidence. A loop controller is connected to the transmission line for transmitting a plurality of address signals cyclically to the terminal units. Means are provided for selecting a blinking mode of operation for the command signals such that respective groups of the light emitting devices are thereby intermittently illuminated at different discrete intervals, the means for selecting being operative such that the ON times for all of the devices, except the first, are the same, but the OFF times are varied in dependence on the number of light emitting devices to be supplied with power.
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