Elevator Door Lock Circuit Monitoring Using Parallel Switch Selection
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Solution Overview
Problem
Existing elevator systems face complex circuit structures and reduced reliability due to the use of numerous relays for monitoring car and landing door lock switches, leading to potential safety hazards from erroneous control signals caused by malfunctioning switches.
Innovation Solution
A device with a selecting unit and processing unit is employed to monitor the state of the landing and car door circuit by coupling door lock switches in parallel with a power supply in different connection states, using contact switches to determine the functionality of individual switches based on level signals at common contact points.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing monitoring devices use a large number of relays for car door lock switch and landing door lock switches, then the monitoring function can be achieved, but the circuit structure becomes complex and reliability is reduced
Solution Approach 1:
The patent merges the monitoring functions of multiple door lock switches into a single integrated circuit. The controller directly monitors all door lock switches (car door lock switch and landing door lock switches) through a unified control circuit, eliminating the need for separate relays for each switch. This consolidation simplifies the circuit structure while maintaining comprehensive monitoring capability, directly resolving the contradiction between reliability and device complexity.
Solution Approach 2:
The patent replaces the mechanical relay-based monitoring system with an electronic controller-based system. Instead of using physical relays to monitor door lock switch states, the invention uses an electronic controller with electronic switching elements (transistors or MOSFETs) and integrated circuits to detect and process switch states. This substitution eliminates mechanical wear and contact issues inherent in relay systems, improving reliability while reducing overall system complexity.
2Reliability
If existing monitoring devices use a large number of relays for door lock switches, then the monitoring function can be achieved, but the cost increases
Solution Approach 1:
The patent combines multiple monitoring functions into a single controller unit that handles all door lock switches (car door and landing door switches) through integrated circuitry. This consolidation reduces the total component count, particularly eliminating the need for multiple expensive relay assemblies, thereby reducing manufacturing costs while maintaining full monitoring functionality.
Solution Approach 2:
The invention replaces expensive mechanical relay components with more cost-effective electronic switching elements and integrated circuits. The electronic controller uses solid-state components (transistors, MOSFETs, integrated circuits) that are generally less expensive than mechanical relays, have longer lifespans, and require less maintenance, thus reducing both initial manufacturing costs and long-term operational costs.
3Measurement precision
If door lock switches remain closed when car stops or doors are opened due to malfunction, then the switches are in abnormal state, but erroneous control signals may be generated causing safety accidents
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously monitors the state of all door lock switches and receives feedback signals about their operational status. The controller compares the expected state (open when doors are opened) with the actual state detected from the switches. When a discrepancy is detected (switch remaining closed when it should be open), the controller generates an alarm signal and prevents erroneous control signals, thereby eliminating the safety hazard while maintaining precise switch state detection.
Data Source
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AI summary
The present application relates to elevator technology and, in particular, to a device and method for monitoring a state of a landing and car door circuit, an elevator system comprising the device, and a non-transitory computer-readable storage medium for implementing the method. A device for monitoring a state of a landing and car door circuit in accordance with an aspect of the present application comprises: a selection unit configured to couple a first landing door lock switch and a second car door lock switch with a power supply in a first connection state, and to couple a second landing door lock switch and a first car door lock switch with the power supply in a second connection state; and a processing unit coupled with the selection unit and configured to cause the selection unit to be in the first connection state or the second connection state, and to determine whether functions of the first landing door lock switch, the second landing door lock switch, the first car door lock switch and the second car door lock switch are normal based on a first level signal at a common contact point of the first landing door lock switch and the second landing door lock switch and a second level signal at a common contact point of the first car door lock switch and the second car door lock switch in the first connection state and the second connection state when a landing door or a car door is opened.