Triplex Cable Communication for Fast Air Conditioner Unit Signaling

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Solution Overview

Problem

Conventional air conditioning systems face challenges in rapid communication between indoor and outdoor units, leading to delayed notification of failures, increased communication traffic, and slow response times due to polling-based communication methods and reliance on relay units.

Innovation Solution

The system employs a triplex cable with a modulator, demodulator, connector, and controller, using a high-voltage capacitor to connect the communication and power wires, allowing direct one-on-one communication between units without relays, and utilizing a modulated-carrier system to reduce noise and enhance communication speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If polling-based communication is used between outdoor unit and indoor units, then communication can be performed using a simple protocol, but communication speed and response time are reduced

Engineering Contradiction:
Improvecommunication speedVSAvoidcommunication protocol complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent inverts the traditional polling-based communication architecture by allowing indoor units to initiate communication with the outdoor unit directly. Instead of the outdoor unit polling each indoor unit in sequence, any indoor unit can transmit data packets to the outdoor unit whenever needed, fundamentally reversing the initiation direction of communication and enabling asynchronous, event-driven communication that significantly improves response time and communication speed.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If relay communication through outdoor unit is used, then indoor units can communicate with each other, but communication latency increases

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidcommunication latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent segments the communication network into direct communication paths, allowing indoor units to communicate directly with each other without mandatory relay through the outdoor unit. The outdoor unit becomes one participant among equals rather than a central relay, creating multiple independent communication paths that reduce latency while maintaining network reliability through direct peer-to-peer data exchange.

Inventive Principle:
Principle #1Segmentation

3Reliability

If high-voltage photo coupler is used in communication circuit, then communication can be achieved, but miswiring protection is insufficient

Engineering Contradiction:
Improvecommunication reliabilityVSAvoidmiswiring damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent implements beforehand cushioning by placing high-voltage capacitors in parallel with the communication circuits before miswiring can occur. These capacitors act as protective elements that can withstand voltage spikes and protect the communication circuit from damage due to cable miswiring, providing advance protection against potential harmful effects without interfering with normal communication operations.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Ease of manufacture

If triplex cable is used for power and communication, then cable laying is simplified, but communication noise increases

Engineering Contradiction:
Improvecable installation easeVSAvoidcommunication noise
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary approach by using the shared wire as both a power carrier and a communication reference, while the communication wire carries the actual data signals. The modulator and demodulator circuits act as intermediaries that convert data signals to voltage variations on the communication wire, using the shared wire as a reference potential. This intermediary signaling method enables reliable communication over the triplex cable while maintaining the installation simplicity of using a single cable for both power and communication.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 configuration enables fast and reliable communication between air conditioning units, preventing miswiring failures and reducing communication latency, allowing for efficient AC power and data transmission using a single triplex cable.

Implementation Method 1

The connector comprises a high-voltage capacitor and connects the communication wire and the shared wire for power and communication to the modulator and the demodulator via the high-voltage capacitor that withstands voltages up to a predetermined level

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

A modulator modulates a voltage signal corresponding to inputted transmission data and outputs the signal as a voltage signal between the communication wire and the shared wire for power and communication

Methodology Applied
Scientific EffectModulation: Phase Modulation

Implementation Method 3

A demodulator demodulates a voltage signal based on the potential difference between the communication wire and the shared wire for power and communication and outputs the signal as a demodulated signal

Methodology Applied
Scientific EffectDemodulation: Phase Modulation

Data Source

PatentEP2679925B1Air conditioning apparatus and air conditioning system
Publication Date: 2020.04.08 MITSUBISHI ELECTRIC CORP
  • EP2679925B1 patent drawingFigure 1
  • EP2679925B1 patent drawingFigure 2
  • EP2679925B1 patent drawingFigure 3A~3C

AI summary

A modulator (21) modulates a voltage signal corresponding to inputted transmission data, and outputs the signal as a voltage signal between a communication wire (3) and a shared wire (4). A demodulator (22) demodulates a voltage signal based on the potential difference between the communication wire (3) and the shared wire (4), and outputs the signal as a demodulated signal. A connector (24) connects the communication wire (3) and the shared wire (4) to the modulator (21) and the demodulator (22) by means of a high voltage capacitor that withstands voltages up to a predetermined level. A controller (25) receives, as incoming data, serial data corresponding to a voltage signal demodulated in demodulator (22) if the serial data includes an address of its own apparatus, monitors a demodulated signal outputted from the demodulator (22), and outputs transmission data that includes a destination address to the modulator (21) if the controller (25) determines that no signal is being transmitted in the communication wire (3).