Test of parallel alarm units

Abstract

Abstract AN IMPROVED SIGNAL INSTALLATION OF A PLURALITY OF ALARM UNITS IS DISCLOSED, THE SIGNAL INSTALLATION ENABLING THE IPERATIONAL READINESS OF EACH ALARM UNTI TO BE CHECKED IN A SIMPLE AND RELIABLE MANNER. THE BASIC SIGNAL INSTALLATION ITSELF COMPRISES A PLURALITY OF INDIVIDUAL ALARM UNITS, EACH ALARM UNIT BEING CONNECTED IN PARALLEL PREFERABLY ACROSS A PAIR OF SUPPLY CONDUCTORS LEADING TO SOME CENTRAL MONITORING STATION. EACH ALARM UNIT IS PREFERABLY OF THE TYPE WHEREIN, AT THE OCCURRENCE OF AN ALARM CONDITION, AN ELECTRICAL CONTACT IS CLOSED THEREIN ESSENTIALLY SHORTING THE SUPPLY CONDUCTORS. FOR PURPOSES OF CHECKING THE OPERATIONAL READINESS OF THE PLURALITY OF ALARM UNITS, ALARM CONDITIONS ARE ELECTRICALLY SIMULTED AT EACH ALARM UNIT. WHEN EACH ALARM UNIT RESPONDS TO THE CHECKING OPERATION, AND ADDITIONAL ELECTRICAL CONTACT ASSOCIATED WITH EACH ALARM IS CLOSED. THE ADDITIONAL OR CHECKING ELECTRICAL CONTACTS ARE CONNECTED IN A SEPARATE SERIES CIRCUIT LEADING BACK TO THE CENTRAL MONITORING STATION. IF ALL ALARMS OF THE PLURALITY OF ALARM UNITS HAVE PROPERLY RESPONDED TO THE CHECKING OPERATION, THEN THE SEPARATE SERIES CIRCUIT COMPRISING ALL THE ADDITIONAL ELECTRICAL CONTACTS WILL BE COMPLETED. SHOULD ONE OF THE PLURALITY OF ALARM UNITS FAIL TO RESPOND, THEN ITS ASSOCIATED ADDITIONAL ELECTRICAL CONTACT WOULD REMAIN IN AN OPEN CONDITION THUS BREAKING THE SERIES CIRCUIT TRIGGERING AN INDICATOR AT THE CENTRAL STATION.

Inventors

• 👤 Andreas Scheidweiler

Bibliographic Details