System and method for power line communication to control fans
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Solution Overview
Problem
Power line control systems face interference and noise issues due to devices like fans, which generate significant electrical noise, affecting data integrity and system stability, and existing solutions either fail to address these issues effectively or require additional infrastructure.
Innovation Solution
A system and method utilizing a controller and emitter with a crystal oscillator to generate a sinusoidal wave, incorporating phase inversion spikes encoded with control information, transmitted over power lines, and received by smart fans with crystal filters to filter out noise and decode instructions for fan operation, allowing for reliable control without additional cables.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If PLC is used to control fans over power lines, then no additional cables are needed and installation is simplified, but electrical noise from fan motors interferes with signal transmission and causes data corruption
Solution Approach 1:
The patent introduces an intermediary device (noise filter or isolator) connected between the power line and the fan motor to block electrical noise from propagating onto the power line while allowing power and PLC signals to pass through. This mediator resolves the contradiction by preventing noise interference without requiring separate control cables.
Solution Approach 2:
The patent extracts the noise-generating component (commutator brushes) from the fan motor design by transitioning to brushless DC motor technology. This eliminates the primary noise source at its origin, allowing reliable PLC communication over the power line without additional cabling infrastructure.
2Reliability
If filtering circuits are added to reduce electrical noise, then signal interference is reduced, but system cost and complexity increase
Solution Approach 1:
The patent implements self-service by integrating noise filtering capabilities directly into the PLC communication module or power supply circuitry of the fan. The system filters its own noise without requiring external filtering circuits, maintaining signal integrity while avoiding additional system complexity.
Solution Approach 2:
The patent merges the noise filtering function with the existing power supply or communication circuitry. By combining multiple functions (power conversion, noise filtering, and PLC communication) into a single integrated module, the system achieves reliable signal transmission without increasing overall device complexity.
3Productivity
If pulse-position modulation is used for PLC communication, then data transmission is achieved over power lines, but the weak pulses are easily interfered with by electrical noise from motor devices
Solution Approach 1:
The patent changes the modulation parameter from pulse-position modulation (PPM) to a more noise-resistant scheme such as frequency-shift keying (FSK) or differential Manchester encoding. This parameter change maintains data transmission capability while significantly improving immunity to electrical noise from motor commutators.
Solution Approach 2:
The patent employs periodic synchronization signals and timing-based protocol design where control messages are sent at regular intervals with predefined timing structures. This periodic action allows the receiver to synchronize to the signal and distinguish valid data from random noise, maintaining productivity while reducing noise susceptibility.
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
Enables effective control of smart fans on noisy power lines by filtering out noise and maintaining signal integrity, allowing for longer transmission distances and avoiding interference with other devices, thus overcoming the limitations of previous power line control technologies.
Implementation Method 1
The emitter itself may include a crystal oscillator, the crystal oscillator may be powered to transmit a signal at a transmission frequency
Implementation Method 2
The one or more smart fans may include a receiver including a crystal filter which may be tuned to filter out all signals on the power line other than a band centered around the transmission frequency
Data Source
AI summary
Disclosed is a system and method for power line control of electrical fans. The system generates a sinusoidal wave using a crystal oscillator. Control information is added to the sinusoidal wave by routing the wave through a phase inversion circuit a predetermined intervals according to a protocol. The resulting control signal is sent on a power line. The control signal is received using a crystal filter, decoded and converted to executable instructions for controlling a fan motor.