Fluid Pump Driving Circuit With Feedback PWM and Voltage Boost
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Solution Overview
Problem
Conventional fluid transportation devices, such as breast pumps, face challenges in miniaturization, noise generation, and operational stability due to the use of conventional motors, which are difficult to integrate with MEMS pumps without redesigning the driving control architecture.
Innovation Solution
A driving circuit that integrates conventional motor-based and MEMS pump architectures by converting input signals to large-width variable rectangular waveforms, utilizing a microprocessor with detection current-feedback circuits to adjust voltage and pulse-width modulation signals, and boosting voltages to meet the demands of both types of pumps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a conventional motor is used to drive the fluid transportation device, then sufficient fluid flow can be achieved, but the device volume becomes large and noise increases
Solution Approach 1:
The patent replaces the conventional motor-driven mechanical system with a piezoelectric-driven MEMS pump system. The piezoelectric element converts electrical energy directly to mechanical deformation, eliminating the need for motors, rotors, and stators. This substitution achieves miniaturization while maintaining fluid transport capability through the piezoelectric effect that causes the pump chamber to expand and contract.
Solution Approach 2:
The patent changes the operating parameters from conventional motor speeds and voltages to piezoelectric excitation frequencies and voltages. The driving circuit generates specific frequency square wave signals that cause the piezoelectric element to deform at optimal frequencies, achieving efficient fluid pumping in a miniaturized configuration.
2Productivity
If a conventional motor is used to drive the fluid transportation device, then sufficient fluid flow can be achieved, but severe noise is generated
Solution Approach 1:
The patent eliminates the noise-generating mechanical components (motors, rotating parts, electromagnetic fields) by substituting them with a piezoelectric-based system. The piezoelectric element operates silently by undergoing reversible deformation in response to electrical signals, producing no mechanical noise while maintaining fluid pumping functionality.
3Volume of moving object
If the fluid transportation device is miniaturized, then portability is improved, but integration with conventional motor-based pumps becomes difficult
Solution Approach 1:
The patent designs a universal driving circuit that can accommodate both piezoelectric MEMS pumps and potentially other pump types. The circuit includes signal generation, voltage amplification, and feedback control components that can be adapted to different pump configurations, enhancing the system's versatility and ease of integration across various applications.
4Volume of moving object
If piezoelectric-driven MEMS pump is used, then noise is reduced and device is miniaturized, but complex voltage control and feedback adjustment are required
Solution Approach 1:
The patent implements a feedback control mechanism where the microprocessor monitors the operating state of the piezoelectric pump and dynamically adjusts the driving voltage and frequency. This feedback loop optimizes the piezoelectric element's deformation characteristics, ensuring efficient fluid pumping while compensating for variations in fluid viscosity, temperature, and pump wear.
Solution Approach 2:
The patent employs periodic square wave voltage signals to drive the piezoelectric element, causing it to expand and contract rhythmically. This periodic excitation is optimized in frequency and amplitude to maximize the pump's efficiency while minimizing energy consumption and heat generation, simplifying the overall control requirements.
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 seamless integration of conventional and MEMS pumps, reducing noise, improving stability, and achieving efficient fluid flow while maintaining a compact and lightweight design, enhancing user experience.
Implementation Method 1
the piezoelectric element is subjected to deformation for transporting fluid due to piezoelectric effect
Implementation Method 2
provide a voltage control signal and a pulse-width modulation (PWM) signal for driving and controlling the fluid pump
Implementation Method 3
The primary boost circuit is configured to convert an input driving voltage with a low voltage into a direct current with a certain high voltage
Data Source
Figure 1A
Figure 1B
Figure 2
AI summary
A driving circuit (200) of a fluid pump module (1) including a microprocessor (104), a primary boost circuit (107) and a pump driving circuit (120) is provided. The microprocessor (104) receives an output signal with a large-width variable rectangular waveform, a driving voltage, a first detection current-feedback signal, and a second detection current-feedback signal. The primary boost circuit (107) converts an inputted driving voltage into a direct current with a certain high voltage. The pump driving circuit (120) receives the certain high voltage and is connected with the microprocessor (104) to receive the voltage control signal and the pulse-width modulation (PWM) signal. The secondary boost circuit (108) receives the certain high voltage to boost the certain high voltage into a working voltage for the fluid pump (200). The operation driving circuit (109) receives the working voltage and provides the pulse-width modulation signal for the fluid pump (200) through the second detection current-feedback signal.