Electrical system and method for protecting premises subject to varying ambient conditions

Claim 1

ELECTRICAL PROTECTION APPARATUS FOR DETECTING THE OCCURRENCE OF AN ALARM CONDITION IN A PLACE SUBJECT TO VARYING AMBIENT CONDITIONS, COMPRISING A FIRST ELECTRICAL PROTECTION SYSTEM HAVING FIRST ELECTRICAL PROTECTION MEANS TO DETECT IN A FIRST MANNER AND WITH A FIRST SENSITIVITY THE OCCURRENCE OF SAID ALARM CONDITION AT SAID PLACE AND TO PRODUCE A FIRST ALARM SIGNAL PROPORTIONAL TO THE MAGNITUDE OF SAID DETECTED ALARM CONDITION, A SECOND ELECTRICAL PROTECTION SYSTEM HAVING SECOND ELECTRICAL PROTECTION MEANS TO DETECT IN A SECOND MANNER AND WITH A SECOND SENSITIVITY THE OCCURRENCE OF SAID ALARM CONDITION AT SAID PLACE AND TO PRODUCE A SECOND ALARM SIGNAL PROPORTIONAL TO THE MAGNITUDE OF SAID DETECTED ALARM CONDITION, SAID SYSTEMS EACH BEING RESPONSIVE IN A RESPECTIVELY DIFFERENT MANNER TO AT LEAST A PARTICULAR AMBIENT CONDITION AT SAID PLACE WHEREBY ANY CHANGE IN SAID PARTICULAR AMBIENT CONDITION PRODUCES A CORRESPONDINGLY DIFFERENT EFFECT ON SAID FIRST AND SECOND ALARM SIGNALS, FIRST AND SECOND ELECTRONIC DEVICES HAVING SEPARATE INPUT CIRCUITS AND HAVING OUTPUT CIRCUITS AT LEAST A PORTION OF WHICH IS COMMON TO SAID DEVICES, MEANS TO DERIVE FIRST AND SECOND BIASING POTENTIALS FROM SAID FIRST AND SECOND ALARM SIGNALS, RESPECTIVELY, AND TO APPLY SAID FIRST AND SECOND BIASING POTENTIALS TO THE INPUT CIRCUITS OF SAID FIRST AND SECOND DEVICES, RESPECTIVELY, THEREBY TO ALTER THE CURRENT FLOW IN SAID COMMON PORTION, MEANS IN SAID COMMON PORTION OF SAID OUTPUT CIRCUITS TO CAUSE A CHANGE IN SAID BIASING POTENTIAL APPLIED TO THE INPUT CIRCUIT OF EITHER ONE OF SAID DEVICES TO ALTER THE CURRENT FLOW OF THE OTHER OF SAID DEVICES IN A DIRECTION OPPOSITE TO THE CORRESPONDING CHANGE IN CURRENT FLOW OF SAID ONE DEVICE, AND MEANS IN SAID COMMON PORTION TO DETECT CHANGES IN CURRENT FLOW IN SAID COMMON PORTION AND RESPONSIVE TO A PREDETERMINED MAGNITUDE OF CURRENT FLOW TO PRODUCE AN ALARM SIGNAL INDICATION.