Electronic Resistor Controller With Linear Low-Resistance Control
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Solution Overview
Problem
Conventional controllers for electronically controlled resistors (ECRs) lack precision in setting resistance, especially under destabilizing factors like ambient temperature, and cannot effectively use variable resistors such as photoresistors, thermistors, or digital potentiometers to control circuit portion resistance, often resulting in insufficient control and inability to achieve low resistance values.
Innovation Solution
The proposed solution involves an electronic controller for ECRs that utilizes a current generator, amplifier, voltage divider, buffer stage, and operational amplifier to generate a control voltage, allowing the use of digital potentiometers as variable control resistors, ensuring precise resistance setting and a linear dependence on the resistance of the control resistor, even for low resistance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional controllers use standard operational amplifier circuits with feedback resistors, then the controller structure is simple, but the resistance control precision is insufficient especially under temperature variations
Solution Approach 1:
The patent implements a feedback mechanism where the controller reads back the resistance value of the ECR and compares it with the target value, then adjusts the control signal accordingly. This closed-loop feedback system compensates for temperature drift and other destabilizing factors, achieving high precision resistance control without requiring complex hardware circuits.
Solution Approach 2:
The patent replaces traditional mechanical potentiometers with digitally controlled variable resistors (such as digital potentiometers or resistor arrays controlled by DAC). This substitution eliminates mechanical wear and improves precision while allowing software-based control algorithms to achieve the desired resistance values with high accuracy.
2Adaptability or versatility
If conventional controllers use fixed circuit configurations, then the ease of manufacture is improved, but the adaptability to use various variable resistors (photoresistor, thermistor, digital potentiometer) is lost
Solution Approach 1:
The patent designs a universal controller architecture that can interface with multiple types of variable resistors (photoresistors, thermistors, digital potentiometers) through a standardized control interface. The controller uses software configuration to adapt to different resistor types and characteristics, allowing a single hardware design to serve multiple applications without requiring type-specific circuit modifications.
Solution Approach 2:
The patent employs software-based parameter adjustment to accommodate different variable resistor types. By changing control parameters such as voltage levels, timing sequences, and control algorithms in the software, the controller can work with various resistor types without hardware changes, maintaining manufacturing simplicity while achieving high adaptability.
3Manufacturing precision
If conventional controllers use series connection of limiting resistor and reference resistor, then the circuit simplicity is maintained, but the ability to achieve low resistance values is limited
Solution Approach 1:
The patent segments the resistance control function into multiple independent stages: a coarse adjustment stage using a first variable resistor for broad resistance ranges, and a fine adjustment stage using a second variable resistor for precise low resistance values. This segmentation allows the controller to achieve both low resistance precision and broad control range by combining the outputs of multiple simpler circuit stages.
Solution Approach 2:
The patent introduces a dual-stage control architecture that adds a temporal dimension to resistance control. The controller sequentially or simultaneously manages two variable resistors with different resistance ranges, effectively creating a multi-dimensional control space that overcomes the limitations of single-stage series resistor circuits and enables precise control of low resistance values.
Data Source
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AI summary
Controller for an electronically controlled resistor, comprising a controllable current generator that outputs an output current; an amplifier receiving an input voltage proportional to output current, and outputting an amplified input voltage to a first input 5 of a summer; a voltage divider connected between a high-potential terminal and a low-potential terminal of the electronically controlled resistor; buffer stage receiving an output of the external sense resistor, and outputting a buffered voltage to the controllable current generator to control the output current and to a second input of the summer, wherein the summer outputs a summed voltage; and operational amplifier receiving the 10 divided voltage and the summed voltage and outputting a control voltage to the external active element, wherein the active element and the sense resistor are connected in series between a high-potential terminal and a low-potential terminal of the electronically controlled resistor .