RF Switch Box Power Harvesting Circuit Without Neutral Wire

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional wireless automation control systems require a Neutral wire, increasing complexity and cost, and are not adaptable to both high and low impedance lamps, leading to overcurrent and overheating issues when improper lamps are used.

Innovation Solution

A power harvesting switch circuit using a main switch with series-connected power MOSFETs and a voltage extractor with series-connected Zener diodes, connected between the Line wire and switch wire, allowing RF-controlled operation without a Neutral wire, with current detection and bypass mechanisms to prevent overcurrent and overheating, and capable of dimming.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a conventional wireless automation control system is used without Neutral wire, then the system can be installed in existing switch boxes, but the system complexity and cost increase due to additional wiring requirements

Engineering Contradiction:

Improveadaptability to existing switch boxesVSAvoidwiring complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The invention extracts the Neutral wire connection requirement from the traditional wireless power switch system. By removing the need for Neutral wire connection, the system can be installed in existing switch boxes that only have Line wire and switch wire, thereby reducing wiring complexity while maintaining adaptability.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The wireless power switch is designed to universally work in both traditional installations (with Neutral wire) and existing switch boxes (without Neutral wire). The circuit architecture supports multiple wiring configurations, making the system adaptable to various installation scenarios without requiring additional wiring.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If a battery is used as power supply instead of Neutral wire, then the system can operate without additional wiring, but battery replacement becomes inconvenient

Engineering Contradiction:

Improvewiring complexityVSAvoidbattery replacement convenience

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The system harvests power directly from the Line wire through the power harvesting circuit, eliminating the need for external battery replacement. The circuit automatically extracts and stores electrical energy from the mains power supply, providing continuous operation without user intervention for power source replacement.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The power supply method is changed from passive battery to active power harvesting from Line wire. By changing the power source parameter from stored chemical energy to harvested electrical energy, the system eliminates battery replacement while maintaining wireless operation.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If a switch box is specifically designed for incandescent lamps, then it works well with low impedance lamps, but it cannot adapt to high impedance lamps like LED bulbs and causes overcurrent and overheating

Engineering Contradiction:

Improveoperation reliability with incandescent lampsVSAvoidlamp type adaptability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention introduces a dynamic control mechanism that adjusts the circuit operation based on the connected lamp type. The controller detects lamp characteristics and dynamically adjusts switching parameters to prevent overcurrent and overheating, enabling reliable operation with both incandescent and LED lamps.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters such as switching frequency and duty cycle based on the connected lamp's impedance characteristics. For high impedance LED lamps, the controller adjusts parameters to prevent overcurrent, while for low impedance incandescent lamps, it maintains appropriate operating conditions, thus preventing overheating in all cases.

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

Enables wireless control of lamps without a Neutral wire, preventing overcurrent and overheating, and allowing dimming of lamps, reducing complexity and cost while accommodating both high and low impedance lamps.

Implementation Method 1

The main switch includes a first power metal-oxide-semiconductor field-effect transistor (MOSFET) and a second power MOSFET connected in series

Methodology Applied

Scientific EffectMOSFET switching:

Implementation Method 2

The voltage extractor includes a first Zener diode and a second Zener diode connected in series but in opposite directions

Methodology Applied

Scientific EffectZener breakdown:

Data Source

PatentUS9961749B1RF controlled switch box without using neutral wire and a power harvesting switch circuit thereof

Publication Date: 2018.05.01 CLIMAX TECH

AI summary

A power harvesting switch circuit includes a main switch and a voltage extractor connected in series between Line wire and switch wire. The main switch includes a first power MOSFET and a second power MOSFET connected in series. The voltage extractor includes a first Zener diode and a second Zener diode connected in series but in opposite directions.