Piezoelectric Pump Drive Circuit Voltage Control

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Solution Overview

Problem

Existing driving devices for piezoelectric elements consume unnecessary power due to current limiting circuits, leading to inefficiencies and potential overheating.

Innovation Solution

A driving device with a voltage regulation circuit, driving signal generation circuit, current limiting circuit, and voltage control circuit that limits current and voltage to prevent power wastage, while incorporating a temperature detector to manage temperature and reduce inefficiencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a current limiting circuit unit is used to prevent overcurrent flowing through the piezoelectric element, then the piezoelectric element is protected from damage, but power corresponding to the limited amount of current is consumed in the current limiting circuit unit, resulting in unnecessary power consumption

Engineering Contradiction:
Improveprotection of piezoelectric elementVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent introduces a voltage control circuit as an intermediary between the power supply and the current limiting circuit. This voltage control circuit dynamically adjusts the operating voltage based on feedback from the current limiting circuit, ensuring that power is only consumed when and where needed, thereby eliminating unnecessary power waste while maintaining protection functionality

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a feedback mechanism where the voltage control circuit receives feedback signals from the current limiting circuit and adjusts the driving voltage accordingly. This closed-loop control ensures that the system operates efficiently by reducing voltage (and thus power consumption) when current limitation is active, while still providing protection when needed

Inventive Principle:
Principle #23Feedback

2Temperature

If current is limited to prevent overheating, then the piezoelectric element is protected from thermal damage, but the driving efficiency decreases due to power wastage

Engineering Contradiction:
Improvetemperature controlVSAvoiddriving efficiency
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The patent employs dynamic voltage adjustment through the voltage control circuit that responds to real-time conditions. The system dynamically increases or decreases the driving voltage based on the operational state and temperature feedback, allowing the piezoelectric element to operate at optimal efficiency when temperature is acceptable, while automatically reducing power to prevent overheating when necessary

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the operating parameters (voltage and current) dynamically based on temperature conditions. The voltage control circuit adjusts the driving voltage parameter in response to temperature feedback, enabling the system to maintain high driving efficiency when temperature is within safe limits while preventing overheating when temperature rises

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

The solution improves driving efficiency for piezoelectric elements by limiting current and voltage, reducing power consumption, and preventing overheating, thereby enhancing the reliability and performance of piezoelectric pumps.

Implementation Method 1

a piezoelectric pump including a piezoelectric element

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3694100B1Drive device and fluid control device
Publication Date: 2024.03.06 MURATA MFG CO LTD
  • EP3694100B1 patent drawingFigure 1~2B
  • EP3694100B1 patent drawingFigure 3~3C
  • EP3694100B1 patent drawingFigure 4~5B

AI summary

A driving device (10) includes a voltage regulation circuit (11), a driving signal generation circuit (12), a current limiting circuit (13), and a voltage control circuit (14). The voltage regulation circuit (11) regulates a power supply voltage and outputs a driving voltage. The driving signal generation circuit (12) generates a driving signal to a piezoelectric element of a piezoelectric pump (20) by using the driving voltage. The current limiting circuit (13) limits a driving current corresponding to the driving voltage to a specified current or less, and generates a current control voltage. The voltage control circuit (14) limits the driving voltage based on the current control voltage.