Filter Circuit Resistance Control for Load-Dependent Power Loss

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Solution Overview

Problem

Existing power supply devices with filter circuits face challenges in controlling power loss variations due to changes in load electric power consumption, leading to inefficient power delivery and potential equipment damage.

Innovation Solution

A filter device incorporating an inductor and a variable DC resistor, coupled with a power calculation circuit and resistance value control circuit, dynamically adjusts the resistance value based on load power consumption and voltage to maintain power loss within a predefined fraction of the load's electric power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the resistance value of the variable resistor is adjusted to reduce power loss, then power loss decreases, but the ability to adapt to varying load conditions deteriorates

Engineering Contradiction:

Improvepower loss of filter circuitVSAvoidadaptation to load variation

Core Design Contradiction:

Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent applies dynamics by making the resistance value of the variable resistor changeable according to load conditions. The control unit dynamically adjusts the resistance value based on detected load power consumption, allowing the filter circuit to adapt to varying load conditions while maintaining optimal power loss characteristics. This transforms a static resistance element into a dynamic one that responds to operational conditions.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using the control unit to detect the power consumption of the load and use this information to adjust the resistance value of the variable resistor. The control unit continuously monitors load conditions and modifies the resistance accordingly, creating a closed-loop control system that optimizes power loss based on actual operational requirements.

Inventive Principle:

Principle #23Feedback

2Device complexity

If a fixed resistance value is used in the filter circuit, then device complexity is reduced, but power loss cannot be controlled under varying load conditions

Engineering Contradiction:

Improvefilter circuit structureVSAvoidpower loss control

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent applies self-service by enabling the filter circuit to automatically adjust its own resistance value based on load conditions. The control unit, integrated within the power supply device, autonomously detects load power consumption and modifies the variable resistor's resistance without requiring external intervention. This allows the system to self-optimize power loss characteristics while maintaining relatively simple overall structure.

Inventive Principle:

Principle #25Self-service

3Ease of operation

If the variable resistor is controlled based on voltage alone, then control simplicity is maintained, but power loss control accuracy deteriorates under varying load power consumption

Engineering Contradiction:

Improvecontrol simplicityVSAvoidpower loss control accuracy

Core Design Contradiction:

Ease of operationVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by transitioning from controlling the variable resistor based solely on voltage to controlling it based on load power consumption. The control unit detects power consumption parameters and uses this information to determine the appropriate resistance value, thereby improving power loss control accuracy while maintaining operational simplicity through automated control.

Inventive Principle:

Principle #35Parameter changes

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

The solution effectively reduces power loss in the filter circuit to a fraction of the load's electric power consumption, ensuring stable power delivery and preventing equipment damage by controlling resistance values to minimize excessive power loss.

Implementation Method 1

a filter circuit having an inductor (12a) connected between a DC power supply (1) and a load (3)

Methodology Applied

Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

a variable DC resistor (12d) connected in parallel to the inductor (12a)

Methodology Applied

Scientific EffectJoule Heating: Joule Heating

Data Source

PatentUS12525869B2Filter device, power supply device, and control device for filter circuit

Publication Date: 2026.01.13 MITSUBISHI ELECTRIC CORP

AI summary

A filter device includes a filter circuit having an inductor connected between a DC power supply and a load, and a variable DC resistor connected in parallel to the inductor. The filter device further includes a power calculation circuit to acquire voltage information showing a DC voltage outputted from the filter circuit to the load, and current information showing a direct current outputted from the filter circuit to the load, and to calculate electric power consumption of the load from the voltage information and the current information, and a resistance value control circuit to control the resistance value of the variable DC resistor on the basis of the electric power consumption calculated by the power calculation circuit and the DC voltage.