APPARATUS FOR SUPERVISING LEADS INTERCONNECTING A PLURALITY OF SELF-CONTAINED ABNORMAL ITION SENSING & ALARM ANNUNCIATING UNITS

摘要

The disclosure describes circuitry associated with a self-contained abnormal condition sensing and alarm annunciating unit for supervising or monitoring leads interconnecting a plurality of such units and for responding to an open circuit condition of such leads so as to actuate an annunciator in a distinctive fashion to signal the open circuit condition.