Motor Control Circuit Feed Diode for Power Window False Catch

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Solution Overview

Problem

Existing power window devices suffer from false catch determinations due to mechanical vibrations causing chatter in the switch element, leading to incorrect motor rotation and window operation issues, especially when the vehicle is not submerged.

Innovation Solution

A motor control circuit with a feed circuit that ensures continuous power supply to the second relay circuit when the switch element chatters, preventing false catch determinations by maintaining reverse rotation of the motor and preventing window opening in submerged states.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a switch element is interlocked with the manipulation switch to short-circuit the second coil when opening the window, then the window opening operation can be performed in submerged state, but the switch element chatters due to mechanical vibration causing false catch determination

Engineering Contradiction:

Improvewindow opening operation in submerged stateVSAvoidfalse catch determination

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

A feed circuit is introduced as an intermediary component between the power supply and the second relay circuit. This feed circuit includes a diode that allows current to flow to the second coil even when the switch element chatters and momentarily opens, thereby maintaining motor reverse rotation and preventing false catch determination while preserving the submerged state opening function

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the switch element chatters due to mechanical vibration, then the current through the second coil is cut off causing motor rotation to stop, but this leads to false determination that catch is generated

Engineering Contradiction:

Improvemanipulation switch operationVSAvoidcatch detection accuracy

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The feed circuit is designed to provide beforehand cushioning by maintaining current flow to the second coil through the diode during switch element chatter. This prevents the motor rotation from stopping and avoids the false catch determination that would otherwise occur due to the temporary interruption

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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

Prevents false catch determinations and ensures accurate window operation by maintaining continuous reverse rotation of the motor and preventing window opening when submerged, thus enhancing the reliability of power window devices.

Implementation Method 1

a diode that allows the current to flow from the power supply to the second coil

Methodology Applied

Scientific EffectDiode: Diode

Implementation Method 2

a motor that opens and closes the window

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS8134312B2Motor control circuit and power window device

Publication Date: 2012.03.13 OMRON AUTOMOTIVE ELECTRONICS CO LTD

AI summary

A motor control circuit includes a manipulation unit, a control unit that drives a motor in a normal rotation direction or a reverse rotation direction, a catch detecting unit that detects a foreign substance caught in the opening and closing body, a first relay circuit that connects one of terminals of the motor to a power supply when the motor is driven in the normal rotation direction, a second relay circuit that connects the other terminal of the motor to the power supply when the motor is driven in the reverse rotation direction, a switch element that cuts off connection to the power supply when the normal rotation command is fed into the control unit from the manipulation unit, a detection circuit, and a feed circuit.