Signal Processing Circuit for Self-Diagnosing Voltage Conversion Drift

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Solution Overview

Problem

Existing voltage measurement systems lack the ability to easily detect drops in conversion precision due to time-dependent deterioration, necessitating cumbersome periodic inspections with high-precision reference devices.

Innovation Solution

A signal processing circuit that utilizes a signal processing unit to compare the correspondence relationship between voltage and frequency data, generated by separate conversion units, to detect errors and correct voltage values based on differences in these relationships, using a reference clock or time-sequence data to enhance precision detection and correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If periodic precision inspection using high-precision reference devices is performed, then conversion precision can be maintained, but operation complexity and time consumption increase significantly

Engineering Contradiction:
Improveconversion precisionVSAvoidinspection complexity
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The voltage measuring device performs self-diagnosis by internally comparing the ADC conversion results with the VFC conversion results. The system uses its own resources (CPU, memory, processing units) to detect precision drops without external reference devices, making the inspection process automatic and eliminating the need for manual intervention with high-precision equipment.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces a frequency conversion unit (VFC) as an intermediary that converts voltage to frequency signals. This intermediary enables indirect comparison between different conversion paths, allowing the system to detect precision drops by comparing corresponding voltage-frequentcy relationships rather than directly measuring voltage against a reference standard.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If periodic precision inspection using high-precision reference devices is performed, then conversion precision can be maintained, but time consumption increases significantly

Engineering Contradiction:
Improveconversion precisionVSAvoidinspection time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The precision detection function operates continuously or periodically without requiring external reference devices. The system automatically performs precision inspections during normal operation by comparing internal conversion results, eliminating the need to stop operations for manual calibration and reducing overall inspection time.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The system performs automatic self-diagnosis using its own processing units and conversion circuits. The CPU automatically compares ADC and VFC results, detects precision drops, and triggers corrections without external intervention, significantly reducing the time required for precision maintenance compared to manual inspection methods.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If dual conversion units (ADC and VFC) are used for precision detection, then precision drop detection capability is improved, but device complexity increases

Engineering Contradiction:
Improveprecision detection capabilityVSAvoidcircuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The frequency conversion unit (VFC) serves multiple functions: it converts voltage to frequency for measurement purposes and simultaneously provides a reference path for precision detection. The CPU and memory units also serve dual purposes by storing both measurement data and precision reference data, and by performing both normal measurement processing and precision detection comparisons.

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

Solution Approach 2:

The patent combines the precision detection function with the existing measurement function by using the same ADC and VFC units for both purposes. The comparison process merges normal data processing with precision verification, and the correction function integrates precision maintenance into the regular operation flow, avoiding the need for separate dedicated precision detection hardware.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4293366B1Signal processing circuit, controller, environment forming device, and signal processing method
Publication Date: 2026.03.11 ESPEC CORP
  • EP4293366B1 patent drawingFigure 1
  • EP4293366B1 patent drawingFigure 2
  • EP4293366B1 patent drawingFigure 3

AI summary

A signal processing circuit includes a first conversion unit that converts a voltage measurement value coming in from a measuring unit, into voltage data and outputs the voltage data, a second conversion unit that converts the voltage measurement value coming in from the measuring unit, into frequency data and outputs the frequency data, a holding unit that holds a first correspondence relationship representing a reference correspondence relationship between a voltage value indicated by the voltage data and a frequency value indicated by the frequency data, and a signal processing unit that detects an error in a case where a second correspondence relationship is different from the first correspondence relationship, the second correspondence relationship representing a correspondence relationship between a voltage value indicated by the voltage data coming in from the first conversion unit and a frequency value indicated by the frequency data coming in from the second conversion unit.