| 摘要 |
PURPOSE:To attain sure emergency communication to a patrol by modulating an alarm signal, sending the result from a transmitter as a high frequency signal, giving it to a line typing a broadcast equipment and a speaker in a building via a capacitor to flow a patrol call signal to the entire building and receiving the call signal by a receiver. CONSTITUTION:When a switch 9 is closed at generation of an alarm signal, a transmitter 4 starts the operation. A transmitter 4 uses an alarm signal to allow a tone encoder to generate a tone for a receiver to be called, the tone is modulated and sent to lines 3a, 3b via capacitors 5a, 5b as a high frequency signal. The supplied high frequency signal is sent to each floor in the building and radiated in each room. Thus, even when a maintenance personnel walks around the building, when the personnel carries a receiver 8 receiving the high frequency signal, the alarm signal is recognized immediately.
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