Alarm transmitter initiation unit using telephone system

摘要

The alarm system comprises a transmitter with automatic ringing function via connections in a telephone system to a receiver. An alarm transmission from the transmitter can be initiated by a manual control for sending a radio signal to activate the ringing function automatically. The transmitted alarm is formed by or contains an identification number corresponding to the transmitter, and the alarm initiation unit contains or is connected to a battery which supplies energy to a transmitter in it. The alarm initiation unit has a monitor for its battery voltage, and when this voltage falls below a predetermined level it alters or completes the signal sent from the initiation unit, pref. in conjunction with the manual effect of that unit. The transmitter, on receipt of the altered or completed signal in addition to the identification number, transmits an alarm in respect of low battery voltage and/or a fault. (Provisional Basic advised week 84/38)