Modular Pump Controller for Stable Pressure via PWM
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Solution Overview
Problem
Conventional small motorized positive-displacement diaphragm pumps rely on mechanically-actuated electrical switches, causing system pressure pulsing, and existing closed-loop pressure control systems are integral with the pump, limiting user flexibility in choosing pumps and requiring a specific controller.
Innovation Solution
A modular, programmable pump controller that automatically determines the switch-opening pressure, providing closed-loop pressure control and automatic pressure alignment, allowing compatibility with various pumps and eliminating the need for human intervention in setting operating pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanically-actuated electrical switch is used to control pump operation based on system pressure, then the pump can be controlled to stop at excessive pressure, but the system pressure pulses due to full power or no power application
Solution Approach 1:
The patent replaces the mechanical pressure switch with an electronic pressure sensor and solid-state PWM controller. The sensor continuously monitors pressure and sends signals to the PWM controller, which smoothly varies motor power output instead of using mechanical on/off switching. This eliminates pressure pulsing while maintaining reliable pressure control.
Solution Approach 2:
The patent implements closed-loop feedback control where the pressure sensor continuously monitors system pressure and the PWM controller periodically adjusts motor power based on the pressure feedback signal. This periodic adjustment maintains stable pressure by dynamically balancing power delivery with system demand.
2Stability of the object's composition
If closed-loop pressure control circuitry is made integral with the pump, then pressure control stability is improved, but user flexibility to choose different pumps is lost
Solution Approach 1:
The patent separates the pressure control function from the pump motor, creating two independent modules: a pump motor and a standalone pressure controller. The controller has a universal interface that can work with various pump types, allowing users to mix and match different pumps while maintaining stable closed-loop pressure control through the universal controller design.
Solution Approach 2:
The patent designs the pressure controller with universal compatibility features including adjustable pressure thresholds, multiple pump interface options, and configurable control parameters. This universality allows a single controller model to work with various pump types and sizes, providing both stable pressure control and user flexibility in pump selection.
3Adaptability or versatility
If the controller is manufactured as a standalone assembly not attached to a pump, then user flexibility is improved, but the complexity of integrating different pump controllers increases
Solution Approach 1:
The patent incorporates programmable parameters in the standalone controller that can be adjusted to match different pump characteristics. The controller allows users to program pressure thresholds, flow rates, and control response parameters specific to each pump type, simplifying integration while maintaining broad compatibility across different pump models.
Data Source
AI summary
A universal controller (16) for an electric motorized pump (18) having a mechanical switch (19) for turning on and off electrical power to the pump, and method of operation of same. The controller controls output pressure of the pump based on controlling the speed of the pump (for example by applying voltage over a greater portion of a duty cycle), so as to provide an optimal operating pressure derived from an automatically determined value for the pressure at which the mechanical switch opens and disrupts electrical power to the pump. It is manufactured as a standalone assembly, not attached to a pump. It can be operated so as to automatically seek and determine a switch-opening pressure for the switch (19), at which the pump pressure switch opens and so interrupts electrical power to the motor, and to then choose an operating pressure below the switch-opening pressure.