Automatic Faucet Sensor Circuit for Touch and Proximity Control

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Solution Overview

Problem

Existing automatic faucets using capacitive or infrared sensors face limitations such as the need for continuous hand presence for filling basins and complexity in control, as well as the requirement for ground connections, which restrict their functionality and usability.

Innovation Solution

A sensor system utilizing a pulse generator connected to an electrode via an inductive circuit, allowing flexible operation as a touch, proximity, or mixed sensor, with a control unit that compares signal thresholds to determine user interaction, enabling advanced control methods without ground connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If capacitive sensors are used for automatic faucets, then touch control is enabled, but ground connection is required and control complexity increases

Engineering Contradiction:
Improvetouch controlVSAvoidground connection requirement
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent extracts the ground connection requirement from the sensor system by using a self-contained capacitive sensing mechanism that generates its own reference potential, eliminating the need for external ground connections while maintaining touch control functionality

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a reference electrode and signal conditioning circuit as intermediaries between the sensing electrode and the control logic, enabling touch detection without requiring direct ground connections to the sensor assembly

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If infrared sensors are used for automatic faucets, then non-contact control is enabled, but continuous hand presence is required for basin filling

Engineering Contradiction:
Improvenon-contact controlVSAvoidcontinuous hand presence requirement
Core Design Contradiction:
Ease of operationVSLoss of time

Solution Approach 1:

The patent makes the sensor system universal by implementing both proximity sensing and touch sensing capabilities within the same capacitive sensor assembly, allowing the system to adapt its control mode based on the user's needs - non-contact for basic operation and touch for extended functions like basin filling

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent implements dynamic control modes where the system automatically transitions between proximity-based control and touch-based control based on detected user intent, allowing flexible operation for different tasks such as quick water activation versus extended basin filling

Inventive Principle:
Principle #15Dynamics

3Adaptability or versatility

If multiple transmitter antennas and receiver antennas are used, then proximity and temperature control are enabled, but system complexity and cost increase

Engineering Contradiction:
Improveproximity and temperature controlVSAvoidmultiple antennas and processor
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes a single capacitive sensor assembly multi-functional by using it for both proximity detection and touch detection, eliminating the need for separate antenna systems while maintaining the ability to control water flow and temperature through different input modes

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of multiple sensors into a single capacitive sensing system that can detect both proximity and touch events, simplifying the overall system architecture while maintaining versatile control capabilities

Inventive Principle:
Principle #5Merging (Combining)

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

The sensor system enhances flexibility and functionality by allowing multi-way faucet control, eliminating the need for ground connections and enabling intuitive operation, including proximity and touch detection, thereby improving user experience and operational simplicity.

Implementation Method 1

A sensor (1) comprises a pulse generator (2) and an electrode (3) connected to an output of the pulse generator by an inductive circuit (4)

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

a detector (6) for detecting a change in an amplitude of a signal present at the electrode (3)

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP3146116B1Detection sensor
Publication Date: 2020.04.22 S T S R
  • EP3146116B1 patent drawingFigure 1~2
  • EP3146116B1 patent drawingFigure 3~4
  • EP3146116B1 patent drawingFigure 5

AI summary

An automatic faucet (100) using such sensor is further described.