Semiconductor Switch Testing for Building Access Doors

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Solution Overview

Problem

Conventional access-determining devices in buildings, such as escape route and fire doors, face challenges in frequent functional testing without disrupting normal operations, as electromechanical relays require de-energization of the electromagnet for testing, leading to undesirable door openings or closures and increased maintenance costs.

Innovation Solution

The implementation of semiconductor switches that can be rapidly switched in a millisecond cycle, allowing for functional testing without de-energizing the electromagnet, ensuring the door remains locked or closed during testing, and redundant switching configurations for fault tolerance, enabling continuous functionality checks without affecting everyday operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromechanical relays are used for switching the electromagnet, then the device can be tested for functionality, but the door must be opened during testing which disrupts normal operations

Engineering Contradiction:
Improveswitch functionalityVSAvoiddoor operation continuity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent replaces electromechanical relays with semiconductor switches (transistors, field-effect transistors, or integrated circuit switches) that can be tested without mechanical movement. This substitution allows the switching function to be maintained while enabling non-intrusive functionality testing that does not require opening the door or disrupting normal operations.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If the switch is opened for functional testing, then the switch functionality can be checked, but the electromagnet is de-energized causing the door to open or close

Engineering Contradiction:
Improveswitch functionalityVSAvoidelectromagnet power
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The patent enables continuous power supply to the electromagnet during testing by using semiconductor switches that can be tested in a conducting state. The testing method applies test signals while the switch remains closed, maintaining continuous electromagnetic field generation and preventing door movement, thus ensuring uninterrupted security function.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent introduces an intermediary testing signal that can be applied through the closed semiconductor switch without interrupting the main power flow to the electromagnet. This intermediary test signal allows functionality verification while the switch remains in its normal conducting state, preventing de-energization of the electromagnet.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If frequent functional testing is performed with electromechanical relays, then switch reliability can be ensured, but maintenance costs and operational disruptions increase

Engineering Contradiction:
Improveswitch functionalityVSAvoidoperational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent replaces electromechanical relays with semiconductor switches that allow for frequent, non-intrusive testing without mechanical wear or operational disruption. This substitution enables continuous monitoring of switch functionality while maintaining normal door operations, thereby increasing both reliability and productivity simultaneously.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

This solution enables frequent and secure functional testing of access-determining devices, ensuring increased security and reduced maintenance costs by allowing for continuous operation and quick detection of switch functionality without impairing the magnetic field or mechanical locking elements.

Implementation Method 1

an electromagnet is energized and this causes a locking element, which is acted upon by a magnetic field generated in this way by the electromagnet

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

at least one door and an electromagnet assigned to the door

Methodology Applied
Scientific EffectElectromagnet: Electromagnet

Data Source

PatentEP2754793B1Access control device in a building
Publication Date: 2019.09.11 ASSA ABLOY SICHERHEITSTECHNIK GMBH
  • EP2754793B1 patent drawingFigure 1
  • EP2754793B1 patent drawingFigure 2
  • EP2754793B1 patent drawingFigure 3

AI summary

The device has a door (10) that comprises two electromagnets (30,32) which is coupled to a voltage source (36) through multiple semiconductor switches. The door is comprised of two locking elements (38,39) for limiting the opening or closing the door in an emergency. The switches are controlled by a control line. Multiple testing devices (60) are adapted to provide an actual open signal for a short period of time for opening the switches. Multiple detection devices are provided to examine whether the switches are opened by the actual open signal. An independent claim is included for a method for testing a semiconductor switch in an access-limiting device of a building.