| 摘要 |
<p>A low voltage audio fire alarm system fully integrated in a paging and music speaker system. The alarm circuits including pull-boxes and automatic fire, smoke and heat detection apparatus and the audio circuits are fully and continuously supervised against component failure by means of a plurality of current responsive relays. The audio path including the speaker system and associated amplifiers is continuously monitored by a low level supersonic 26KC signal. Fail-safe features utilizing multi-contact switches and relays are incorporated throughout the system to prevent inadvertent silencing of alarms in the absence of an alarm condition.</p> |
