Methods and apparatus for controlling and testing a notification appliance circuit
First Claim
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1. An extension loop alarm notification output arrangement for use in a safety notification system, comprising:
- a) a notification extension loop connected to the safety notification system that generates an alarm notification output signal, configurable into a first and second wiring configurations of a notification appliance circuit;
b) a negative voltage source configured to generate a negative voltage for testing the continuity of the first and second wiring configurations of the notification appliance circuit;
c) a first resistor arrangement coupled between the negative voltage source and a signal output of the notification extension loop, the signal output configured to be electrically coupled to a feed conductor of the first or second wiring configuration of the notification appliance circuit;
d) a processing circuit operably coupled to a circuit arrangement configured to detect a first voltage at the signal output of the notification extension loop, the processing circuit configured to generate a trouble signal output if the first voltage at the signal output is above a first threshold or below a second threshold;
e) a positive voltage source configured to generate a positive voltage responsive to said alarm notification output signal to actuate said notification appliance circuit; and
f) a semiconductor switch arrangement coupled to the signal output that is switchable between a first state in which the positive voltage is applied to the signal output and a second state in which the negative voltage is applied to the signal output;
wherein the circuit arrangement includes a test voltage measurement circuit for said testing and configured to generate a measurement signal output based on the first voltage, and the processing circuit configured to obtain the measurement signal output and to generate a comparison value representative of a difference between a reference voltage and the first voltage for generating indication of circuit faults; and
wherein the reference voltage is equal to the negative voltage divided over the first resistor arrangement and an end of line resistor arrangement of the notification appliance circuit.
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Abstract
An arrangement for use in a safety notification system includes a source of negative voltage, a first resistor arrangement, and a circuit arrangement. The first resistor arrangement is coupled between the source of negative voltage and the signal output of the safety notification system. The circuit arrangement is configured to detect a first voltage at the signal output of the safety notification system, and to generate a trouble signal output if the first voltage at the signal output is above a first threshold or below a second threshold.
51 Citations
13 Claims
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1. An extension loop alarm notification output arrangement for use in a safety notification system, comprising:
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a) a notification extension loop connected to the safety notification system that generates an alarm notification output signal, configurable into a first and second wiring configurations of a notification appliance circuit; b) a negative voltage source configured to generate a negative voltage for testing the continuity of the first and second wiring configurations of the notification appliance circuit; c) a first resistor arrangement coupled between the negative voltage source and a signal output of the notification extension loop, the signal output configured to be electrically coupled to a feed conductor of the first or second wiring configuration of the notification appliance circuit; d) a processing circuit operably coupled to a circuit arrangement configured to detect a first voltage at the signal output of the notification extension loop, the processing circuit configured to generate a trouble signal output if the first voltage at the signal output is above a first threshold or below a second threshold; e) a positive voltage source configured to generate a positive voltage responsive to said alarm notification output signal to actuate said notification appliance circuit; and f) a semiconductor switch arrangement coupled to the signal output that is switchable between a first state in which the positive voltage is applied to the signal output and a second state in which the negative voltage is applied to the signal output; wherein the circuit arrangement includes a test voltage measurement circuit for said testing and configured to generate a measurement signal output based on the first voltage, and the processing circuit configured to obtain the measurement signal output and to generate a comparison value representative of a difference between a reference voltage and the first voltage for generating indication of circuit faults; and wherein the reference voltage is equal to the negative voltage divided over the first resistor arrangement and an end of line resistor arrangement of the notification appliance circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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Specification