Power Line Communication Modulator Placement for Signal Attenuation

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Solution Overview

Problem

Conventional Power Line Communication (PLC) systems experience signal attenuation due to capacitive loads connected to the power source line, limiting effective communication timing and efficiency.

Innovation Solution

A communication system design where the modulation unit is placed closer to the loads and the demodulation unit closer to the battery, using semiconductor transistors and high pass filters to superimpose and demodulate signals on the power source line, reducing attenuation and noise interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the PLC modulator is placed closer to the battery (conventional configuration), then the communication signal can be superimposed on the power source line, but the communication signal is attenuated when other capacitive loads are connected to the power source line

Engineering Contradiction:

Improvecommunication signal qualityVSAvoidsignal attenuation

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent inverts the conventional PLC configuration by placing the modulator closer to the loads and the demodulator closer to the battery. This reversal changes which side of the power line the communication signal is superimposed on, thereby avoiding the capacitive load attenuation problem that occurs when signaling near the battery side with parallel load connections.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If other loads are separated from the power source line during PLC communication, then signal attenuation is reduced, but the timing for performing communication is limited

Engineering Contradiction:

Improvecommunication signal qualityVSAvoidcommunication timing flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

By inverting the PLC configuration to superimpose signals on the load side rather than the battery side, the system maintains continuous communication capability without requiring load separation. The inverted topology allows communication to proceed regardless of load connection states, eliminating timing restrictions while preserving signal quality.

Inventive Principle:

Principle #13The other way round (Inversion)

3Speed

If a pulse communication signal with rapid rise and fall is used, then communication speed is improved, but conductive noise increases

Engineering Contradiction:

Improvecommunication speedVSAvoidconductive noise

Core Design Contradiction:

SpeedVSObject-generated harmful factors

Solution Approach 1:

The patent modifies the temporal parameters of the communication signal by implementing gradual rise and fall times instead of abrupt transitions. This parameter change reduces high-frequency spectral content and minimizes conductive noise generation, while the system maintains effective communication speed through the modified pulse characteristics.

Inventive Principle:

Principle #35Parameter changes

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 effectively suppresses signal attenuation, reduces costs by eliminating the need for separate transistors, and enhances demodulation precision by differentiating and comparing voltage signals, providing a reliable communication system without increasing system complexity.

Implementation Method 1

a modulation unit that superimposes the communication signal from the transmission unit on the power source line

Methodology Applied

Scientific EffectSuperposition:

Implementation Method 2

a high pass filter that differentiates a power source on the power source line on which the communication signal is superimposed

Methodology Applied

Scientific EffectDifferentiation:

Implementation Method 3

a comparing unit that compares the differentiated voltage with a reference voltage and outputs a comparison result as the demodulated communication signal

Methodology Applied

Scientific EffectVoltage comparison:

Data Source

PatentUS9929773B2Communication system

Publication Date: 2018.03.27 YAZAKI CORP

AI summary

A slave control device receives a communication signal from a master control device, and controls loads according to the received communication signal. A modulator superimposes the communication signal from the master control device on power source lines, and a demodulator demodulates the communication signal superimposed on the power source lines and supplies the demodulated communication signal to the slave control device. The modulator is provided on power source lines on a battery side, and the demodulator is provided on the power source lines on a load side. The modulator superimposes the communication signal on the power source lines which are on a side closer to the loads with respect to the modulator among the power source lines.