Audio Riser Active Electrical Supervision for Fire Alarm Systems
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Solution Overview
Problem
Conventional fire alarm systems fail to isolate circuit faults effectively when the system is in active mode, leading to disruptions across all zones due to series configuration of input device circuits and notification appliance circuits, and existing solutions are impractical for monitoring during both standby and active modes without causing audio noise or damage.
Innovation Solution
An audio riser active electrical supervision system that includes a high-voltage audio alert system and isolator modules, capable of disconnecting faulty circuit nodes while maintaining connectivity to remaining nodes, using a DC supervision voltage and AC coupling to monitor for faults independently of the audio signal, allowing for isolation during both standby and active modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a series configuration of IDCs and NACs is used on a common riser, then the system structure is simple and easy to install, but a fault in any given zone or device will affect all other zones or devices in the circuit
Solution Approach 1:
The patent divides the continuous series circuit into segmented zones by introducing isolator modules at each zone. Each isolator module can independently open or close circuit breaks to segment the circuit, allowing fault isolation to specific zones while maintaining operation in other zones. This segmentation resolves the contradiction by maintaining the simplicity of series configuration while adding fault isolation capability through modular segmenting.
Solution Approach 2:
The patent introduces isolator modules as intermediary devices between zones on the riser circuit. These isolators act as mediators that can detect faults and automatically open circuit breaks to prevent fault propagation. The isolators serve as the intermediary mechanism that enables fault isolation without requiring complete circuit redesign, thus maintaining system simplicity while improving reliability.
2Measurement precision
If DC supervision voltage is applied to monitor circuit faults during active mode, then fault detection capability is improved, but audio noise or damage may occur due to interaction with high-voltage audio signal
Solution Approach 1:
The patent extracts the DC supervision voltage monitoring function from the main audio signal path by using coupling capacitors. The supervision voltage is taken out through the capacitor to a separate monitoring circuit, allowing fault detection without the DC voltage interfering with the high-voltage audio signal. This extraction resolves the contradiction by enabling monitoring while preventing harmful interactions.
Solution Approach 2:
The patent uses coupling capacitors as intermediary elements between the DC supervision voltage and the monitoring circuit. The capacitor acts as a mediator that allows the DC voltage to be monitored while blocking it from reaching the audio signal path, thus preventing audio noise and damage. This intermediary approach enables fault detection capability while eliminating harmful effects.
3Reliability
If isolator modules are added to enable fault isolation during active mode, then circuit fault isolation is improved, but device complexity and cost increase
Solution Approach 1:
The patent merges multiple functions into the isolator module: fault detection, circuit breaking, and supervision voltage monitoring are all combined in a single modular unit. By merging these functions, the system achieves improved fault isolation capability without proportionally increasing overall system complexity. The modular design allows for standardized implementation that manages complexity while delivering enhanced reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables effective isolation of circuit faults without affecting other zones, meeting regulatory standards by monitoring high-voltage audio riser circuits during both modes, ensuring continuous operation of remaining nodes and compliance with emergency system regulations.
Implementation Method 1
the AC coupling device combines the DC voltage and the high-voltage analog signal in response to invoking the active alert mode
Implementation Method 2
a low pass filter connected between the DC voltage supply and a respective circuit node, the low pass filter configured to block the high-voltage analog signal from passing therethrough while passing the DC voltage signal to the isolator module
Data Source
AI summary
An audio riser active electrical supervision system includes a high-voltage audio alert system connected to a riser circuit. The high-voltage audio alert system disconnects a high-voltage analog signal from the riser circuit when the audio riser active electrical supervision system operates in a standby mode, and connects the high-voltage analog signal to the riser circuit when the audio riser active electrical supervision system operates in an active alert mode. A plurality of isolator modules operate in a closed state that connects a circuit node to the riser circuit and an open state that disconnects the respective circuit node from the riser circuit. A riser supervision circuit is connected to at least one isolator module to detect a circuit fault on the riser circuit when the audio riser active electrical supervision system operates in the standby mode and the active alert mode.