73185759
Sep 15, 1978
Jul 3, 1979
ELECTRICAL APPARATUS FOR INTERFACING AN ELECTRICAL PROTECTION CIRCUIT AT ONE PLACE WITH A SIGNAL TRANSMISSION SYSTEM INTENDED TO TRANSMIT ELECTRICAL PROTECTION SIGNALS OF THE FIRE, BURGLARY, HOLD-UP AND SUPERVISORY TYPE TO ANOTHER PLACE SUCH AS A CENTRAL STATION WHERE APPROPRIATE ACTION CAN BE INITIATED
Electrical and Scientific Apparatus