Current Loop Communication Circuit With Switching Power Supply

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Solution Overview

Problem

The existing current loop communication circuit in air conditioners experiences significant heat generation due to high power consumption by the voltage divider resistor and has layout constraints due to its large volume, which is not conducive to PCB design.

Innovation Solution

The air conditioner current loop communication circuit incorporates a switching power supply module connected in series with the AC power connection wire to output DC power, replacing the traditional resistance voltage divider, and includes unidirectional and overcurrent protection modules to ensure safe and efficient communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a voltage dividing resistor is used to provide DC power to the current loop communication circuit, then the communication circuit can operate, but the power consumption is high causing severe heat generation

Engineering Contradiction:

Improvecommunication circuit operationVSAvoidheat generation

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent changes the power supply mode from resistive voltage division to switching power supply, fundamentally altering the electrical parameters and operating principles to achieve efficient DC power generation with minimal heat loss

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the passive resistive voltage division mechanism with an active switching power supply system, substituting a thermally inefficient mechanical/electrical system with a more efficient electronic conversion system

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If a voltage dividing resistor is used to provide DC power, then the communication circuit can function, but the resistor volume is large impacting PCB layout

Engineering Contradiction:

Improvecommunication circuit functionVSAvoidvoltage dividing resistor volume

Core Design Contradiction:

ReliabilityVSVolume of moving object

Solution Approach 1:

The patent transforms the power supply approach from high-power resistive division requiring large physical components to efficient switching power conversion enabling compact integrated circuit implementation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent substitutes the bulky resistive voltage division hardware with a compact switching power supply module that can be integrated on PCB, eliminating the need for large discrete resistors

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Power

If a voltage dividing resistor is used, then DC power can be generated, but the power consumption is high leading to energy waste

Engineering Contradiction:

ImproveDC power generationVSAvoidpower consumption

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent fundamentally changes the power conversion methodology from continuous resistive dissipation to pulsed switching conversion, dramatically improving energy efficiency by minimizing resistive losses during power transfer

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces the energy-wasteful resistive voltage division system with an efficient switching power converter that uses electromagnetic induction and electronic switching to minimize energy loss during DC power generation

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 reduces heat generation and improves PCB layout by eliminating the need for a large voltage divider resistor, while maintaining compatibility with existing communication circuits and ensuring reliable communication between indoor and outdoor units.

Implementation Method 1

the switching power supply module includes a switching transformer. The first output winding is configured to output a first DC to the current loop communication loop to provide a DC power source

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The DC power supply circuit includes a voltage dividing resistor that divides the AC power source, a diode for rectification

Methodology Applied

Scientific EffectRectification: Diode

Data Source

PatentUS11378294B2Air conditioner current loop communication circuit and air conditioner

Publication Date: 2022.07.05 GD MIDEA AIR CONDITIONING EQUIP CO LTD

AI summary

An air conditioner current loop communication circuit includes an indoor unit current loop communication circuit and an outdoor unit current loop communication circuit connected to each other via a communication connection wire and an AC power connection wire to form a current loop communication loop, an indoor microcontroller unit (MCU) and an outdoor MCU configured to communicate with each other through the current loop communication loop, and a switching power supply circuit connected in series to the communication connection wire or the AC power connection wire and configured to output a DC power to the current loop communication loop.