Isolator Circuit With Optical Switch For Fire Detection Loops
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing detector systems, such as fire detection systems, face limitations in isolating sections for maintenance or installation while ensuring continuous functionality and protection against short circuits, leading to reduced fire protection and potential damage from surges.
Innovation Solution
Incorporating an isolator circuit with a switch controlled by an optical data receiver, allowing remote isolation and automatic protection against short circuits, ensuring power supply to detectors even during isolation, and using a bidirectional power control line with a diode arrangement to prevent damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If an isolator module is installed on each loop to isolate sections for maintenance or installation, then the ability to isolate sections is improved, but detector units are unnecessarily isolated and fire protection is limited
Solution Approach 1:
The patent divides the isolation function into two independent parts: communication isolation (via opto-isolator) and power isolation (via relay switch). This segmentation allows selective isolation of communication while maintaining power supply, or selective isolation of power while maintaining communication, resolving the contradiction between isolation capability and system reliability.
Solution Approach 2:
The patent implements dynamic control of isolation states through bidirectional communication between the control unit and isolator module. The system can dynamically adjust isolation based on operational needs, maintenance requirements, or fault conditions, rather than maintaining fixed isolation states, thus preserving fire protection coverage while enabling maintenance operations.
2Ease of operation
If an isolator module is used to isolate sections, then isolation is achieved, but the detector units cannot receive power and are unable to detect fires
Solution Approach 1:
The patent separates power control and communication control into independent circuits with separate switching mechanisms. The power control line includes a relay switch controlled independently from the communication line's opto-isolator, allowing selective activation of power isolation while maintaining communication, or vice versa, thus preventing unnecessary power cutoff to detectors.
Solution Approach 2:
The patent introduces a relay switch as an intermediary device between the control unit and the power supply circuit. This intermediary provides controlled, selective power isolation based on specific conditions (such as detected faults or maintenance mode), rather than blanket isolation, ensuring detectors remain powered unless isolation is explicitly required for safety or maintenance reasons.
3Reliability
If isolator modules are installed to protect against short circuits, then protection is provided, but a number of detector units may be disabled
Solution Approach 1:
The patent implements fine-grained segmentation of circuit protection by providing separate relay switches for each isolator module's power control line. When a short circuit is detected, the control unit can activate only the specific relay corresponding to the affected circuit segment, isolating the fault while leaving other detector units operational, thus maximizing the number of functional detectors during fault conditions.
Solution Approach 2:
The patent applies local quality control by enabling independent fault isolation at each isolator module location. Each module can independently respond to local fault conditions without affecting other parts of the system, allowing protection against short circuits to be applied locally rather than system-wide, thereby preserving the functionality of detector units not involved in the fault.
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 remote isolation of sections for maintenance or installation without disrupting the fire detection system, protecting detectors from short circuits and ensuring continuous functionality by maintaining power supply, thus enhancing safety and reducing the risk of damage.
Implementation Method 1
an optical data receiver for receiving an optical data signal from an external source
Implementation Method 2
a diode arrangement to prevent damage
Data Source
Figure 1
Figure 2
AI summary
An isolator circuit (25) for a unit of a safety system (10) includes a power control line (14) connectable to a first loop of a safety system and a power connection (16) connectable to a second loop of the safety system. A switch (26) is connected to the power control line (14), and the switch has a closed configuration and an open configuration. A controller (28) controls the configuration of the switch (26). If a voltage across the circuit (10) from the power connection (16) to the power control line (14) falls below a predetermined level, the controller (28) opens the switch (26), thereby causing a disconnection to occur in the first loop.