Magnetic Latching Relay Protection via Induced Current Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetic latching relays in fire alarm systems are prone to unintended state changes due to mechanical impacts, which can compromise safety and reliability, especially during tests like the UL864 jarring test, and existing solutions like shock-absorbing materials are costly and impractical.
Innovation Solution
A relay protection device that includes a current detector, comparator, and controller to measure induced currents and apply a retention voltage to maintain the switching mechanism's state, preventing unwanted changes due to external forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a relay is made sufficiently robust to have high resistance to impulse forces, then reliability is improved, but the relay becomes bulky and heavy
Solution Approach 1:
The patent replaces mechanical shock absorption structures with an electronic detection and response system. The current detector monitors induced currents that indicate mechanical impact, and the controller activates the electromagnetic device to generate counteracting magnetic fields, substituting mechanical robustness with electronic control.
Solution Approach 2:
The patent changes the operational parameters of the relay by dynamically adjusting the electromagnetic field strength based on detected impact conditions. The controller modifies the current through the electromagnetic device in response to detected induced currents, allowing the relay to adapt its resistance to impulse forces electronically rather than through fixed mechanical design.
2Reliability
If mechanical shock absorbing features are added to the relay enclosure, then reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent replaces mechanical shock absorbing features with an electronic system comprising a current detector and controller. This substitution eliminates the need for complex mechanical damping structures, foam materials, or rubber mounts, thereby simplifying manufacturing while maintaining protection against impulse forces.
Solution Approach 2:
The relay system monitors its own state through the current detector and automatically responds to detected impacts by activating the electromagnetic device. This self-monitoring and self-protection capability eliminates the need for external mechanical protection structures, reducing manufacturing complexity.
3Volume of moving object
If the relay is made less bulky to fit constrained spaces, then ease of installation is improved, but resistance to impulse force decreases
Solution Approach 1:
The patent enables compact relay design by replacing mechanical reinforcement structures with electronic protection. The current detector and controller system provides impulse force resistance without requiring additional physical space, allowing the relay to maintain small volume while achieving high reliability.
4Use of energy by moving object
If magnetic latching relays are used to limit power consumption, then energy efficiency is improved, but susceptibility to unintended state changes from mechanical impact increases
Solution Approach 1:
The patent introduces a feedback mechanism where the current detector monitors induced currents that indicate mechanical impact, and the controller responds by activating the electromagnetic device to counteract the impact effect. This feedback loop maintains state stability without requiring continuous power consumption, preserving the energy-efficient characteristics of magnetic latching relays.
Solution Approach 2:
The system takes preliminary action by detecting induced currents before they can cause state changes. The controller activates the electromagnetic device in response to detected impacts, preventing unintended state changes before they occur, thereby maintaining reliability without continuous power consumption.
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
The solution effectively prevents unintended state changes in magnetic latching relays, ensuring reliability and safety during mechanical impacts, allowing for the use of less robust and cost-effective relays in constrained spaces while meeting performance standards.
Implementation Method 1
the controller is, based on the determination of the comparator, operable to apply a retention voltage across the electrical control contacts so as to cause the electromagnetic device to generate a magnetic field to retain the switching mechanism in its current state
Implementation Method 2
the current detector is operable to detect the current induced by the switching mechanism by measuring a voltage across the electrical control contacts
Data Source
AI summary
A relay protection device is disclosed for use with a magnetic latching relay, the relay having two stable states. The relay comprises an electromagnetic device which under the effect of a switching impulse current, causes the relay to switch from one of the states to the other. The relay protection device comprises a current detector for connection with electrical control contacts of the relay, which measures a current induced by the switching mechanism, a comparator operable to determine if the current exceeds a predetermined threshold, and a controller for connection with the electrical control contacts and, based on the determination of the comparator, operable to apply a retention voltage across the electrical control contacts so as to cause the electromagnetic device to generate a magnetic field to retain the switching mechanism in its current state.