Multi-Channel Current Output Correction Using a Shared Reference Resistor

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Solution Overview

Problem

Conventional current output devices require highly accurate reference resistors for each channel in multi-channel applications, leading to increased costs.

Innovation Solution

A current output device comprising multiple current output units, an alternative current generation unit, a signal conversion unit, and an output current correction unit, where the alternative current generation unit generates a current that substitutes for the output current using a resistor integrated in the circuit, and the signal conversion unit converts this alternative current into a voltage signal for correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a highly accurate reference resistor is used for each channel in a multi-channel current output device, then the output current detection accuracy is improved, but the device cost increases

Engineering Contradiction:
Improveoutput current detection accuracyVSAvoiddevice cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent divides the current detection function into two parts: a coarse detection using low-accuracy integrated circuit resistors for each channel, and a fine correction using a single high-accuracy reference resistor shared across all channels. This segmentation allows each channel to have basic detection capability without requiring expensive high-precision resistors everywhere, thus reducing overall cost while maintaining adequate measurement precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The high-accuracy reference resistor is designed to serve multiple channels simultaneously through the correction mechanism. Instead of dedicating one expensive high-precision resistor to each channel, a single universal reference resistor provides correction signals that benefit all channels, achieving multi-functionality and significantly reducing the total number of high-precision components required.

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

2Stability of the object's composition

If a highly accurate reference resistor is used for each channel, then the output current stability is improved, but the device complexity increases

Engineering Contradiction:
Improveoutput current stabilityVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent merges the correction functionality across all channels into a unified correction circuit that uses a single high-accuracy reference resistor. Instead of having independent correction circuits for each channel (which would increase complexity), the correction mechanism is combined and shared, reducing device complexity while still providing stability improvement for all channels through the common correction signal.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If low-accuracy resistors are used in integrated circuits, then the device cost is reduced, but the output current detection accuracy deteriorates

Engineering Contradiction:
Improvedevice costVSAvoidoutput current detection accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent introduces a correction circuit as an intermediary between the low-accuracy integrated circuit resistors and the final output current. This correction circuit uses the single high-accuracy reference resistor to generate correction signals that compensate for the inaccuracies of the integrated circuit resistors, effectively mediating between the low-cost sensing elements and the high-precision output requirement.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent implements a feedback mechanism where the voltage from the high-accuracy reference resistor is compared with the voltage from the integrated circuit resistor, and the difference is used to generate a correction signal. This feedback loop continuously compensates for the inherent inaccuracies of the low-accuracy integrated circuit resistors, maintaining detection accuracy while allowing the use of cost-effective components.

Inventive Principle:
Principle #23Feedback

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

This configuration simplifies the current output device, reduces the need for high-accuracy resistors, and lowers costs while maintaining accurate output current stabilization across multiple channels.

Implementation Method 1

an alternative current generation unit that generates an alternative current on the basis of a resistor arranged in an integrated circuit which also includes the current output units, the alternative current being a current that substitutes for the output current of the current output units

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Implementation Method 2

a signal conversion unit that converts the alternative current into a voltage signal on the basis of a reference resistor

Methodology Applied
Scientific EffectElectrical Resistance: Electrical Resistance

Data Source

PatentEP4557042A1Current output device
Publication Date: 2025.05.21 YOKOGAWA ELECTRIC CORP
  • EP4557042A1 patent drawingFigure 1
  • EP4557042A1 patent drawingFigure 2
  • EP4557042A1 patent drawingFigure 3

AI summary

A current output device (1) has a plurality of current output units (320, 330, 340, 350), an alternative current generation unit (390), a signal conversion unit, and an output current correction unit (101, 102, 103, 104). The current output unit (320, 330, 340, 350) outputs, to an external circuit, an output current based on an output current signal that is input. The alternative current generation unit (390) generates an alternative current, which is a current that substitutes for the output current of the current output unit (320, 330, 340, 350), on the basis of a resistor (322) arranged in an integrated circuit (30, 31) which also includes the current output units (320, 330, 340, 350). The signal conversion unit converts the alternative current into a voltage signal on the basis of a reference resistor (110). The output current correction unit (101, 102, 103, 104) is arranged for each of the current output units (320, 330, 340, 350) and generates the output current signal on the basis of a difference between the voltage signal and a target value.