Heat Exchange Cooler Power Circuit With Automatic Tap Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional heat exchange coolers face reliability and cost issues due to temperature sensitivity and complex wiring, and power circuit driving devices experience high-frequency noise radiation and manual tap switching challenges, leading to increased installation time and potential errors.

Innovation Solution

The implementation of sensor-less DC brushless motors for both indoor and outdoor fans, along with a commercial power transformer with automatic tap switching and output voltage detection, reduces temperature sensitivity, eliminates noise radiation, and automates voltage adjustments, thereby enhancing reliability and reducing installation time and costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If magnetic sensors (Hall elements) are installed in outdoor DC brushless motors for temperature sensing, then temperature control accuracy is improved, but the motors become sensitive to low-temperature environments and require installation in locations with ambient temperature above -30°C

Engineering Contradiction:
Improvetemperature control accuracyVSAvoidmotor operation reliability in low temperature
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The magnetic sensor (Hall element) is extracted and removed from the outdoor DC brushless motor. Instead of using a magnetic sensor within the motor to detect temperature, the patent uses sensor-less control that relies on current detection and computational models to estimate rotor position and temperature, thereby eliminating the component that fails in low-temperature environments.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The mechanical/magnetic sensing system (Hall element) is replaced with an electronic computational system. The patent employs sensor-less control algorithms that use current waveforms, voltage measurements, and mathematical models to infer rotor position and temperature without physical sensors, substituting direct magnetic measurement with computational estimation.

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

2Adaptability or versatility

If long relay leads are used to connect outdoor DC brushless motors with electronic control units, then motor control flexibility is improved, but signal noise interference increases and faulty operation occurs

Engineering Contradiction:
Improvemotor control flexibilityVSAvoidsignal noise interference
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The sensor signal lead is extracted and eliminated from the system. By removing the magnetic sensor, the long relay lead carrying sensor signals is no longer needed. The patent uses sensor-less control where rotor position information is obtained through current detection and computational algorithms rather than physical sensor leads.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

An intermediary computational system is introduced between the motor and control unit. Instead of directly transmitting sensor signals through long leads, the patent uses current waveforms as an intermediary carrier of rotor position information, processed through mathematical models and algorithms to extract position data without requiring dedicated sensor signal paths.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Adaptability or versatility

If manual tap switching is implemented in power circuit driving devices, then voltage adjustment flexibility is improved, but installation time increases and installation errors occur

Engineering Contradiction:
Improvevoltage adjustment flexibilityVSAvoidinstallation time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The power circuit driving device performs self-service by automatically detecting input voltage levels and selecting appropriate transformer taps without manual intervention. The system uses voltage detection circuits to monitor input voltage and automatically switches transformer taps to maintain optimal output voltage, eliminating the need for installers to manually configure voltage settings.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

A feedback mechanism is implemented where the power circuit continuously monitors input voltage levels and automatically adjusts transformer tap selection accordingly. The voltage detection circuit provides feedback about input voltage conditions, and the control system responds by selecting the appropriate tap configuration to maintain stable output voltage across varying input conditions.

Inventive Principle:
Principle #23Feedback

4Use of energy by moving object

If high-frequency switching power circuits are used for power conversion, then power conversion efficiency is improved, but high-frequency noise radiation increases

Engineering Contradiction:
Improvepower conversion efficiencyVSAvoidhigh-frequency noise radiation
Core Design Contradiction:
Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful high-frequency noise radiation into a beneficial filtering opportunity. By using a transformer with higher frequency characteristics, the system generates high-frequency noise that is then effectively filtered by the transformer's inherent inductance and capacitance, transforming the harmful radiation into a controlled electromagnetic field that aids in noise suppression rather than causing interference.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 provides a reliable, cost-effective heat exchange cooler that operates across varying temperatures without magnetic sensors, reduces noise interference, and automates voltage adjustments, resulting in a more efficient and less labor-intensive installation process.

Implementation Method 1

heat exchanging element 105 for exchanging sensible heat of the outside air and inside air

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

air is passed through heat exchanging element 105

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

indoor DC brushless motor 103 and outdoor DC brushless motor 107

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 4

a pole sensor such as a Hall element

Methodology Applied
Scientific EffectHall effect: Hall Effect

Data Source

PatentEP1921391B1Heat-exchange cooling device and power supply circuit driver used therefore
Publication Date: 2012.10.03 PANASONIC HOLDINGS CORP
  • EP1921391B1 patent drawingFigure 1~2
  • EP1921391B1 patent drawingFigure 3
  • EP1921391B1 patent drawingFigure 4A~4B

AI summary

A heat exchange cooler capable of eliminating continuous radiation of high-frequency noise waves and reducing the man hour for the installation work, and a power circuit driving device used for it are provided. A commercial power transformer (311), which transforms commercial AC power (307) supplied from a heat generating element storing box to a specified range of voltage, is provided. Moreover, first relay (210) and second relay (212) are used for automatically switching a plurality of taps disposed at the coil of commercial power transformer (311) which keeps a wide range of commercial AC voltage from 200V to 250V in nominal voltage within a specified range of output voltage.