Switch and method for temperature measurement and temperature sensor

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Solution Overview

Problem

Existing temperature measurement circuits for cooking appliances are limited in evaluating multiple temperature-dependent resistances, requiring a multi-pole line for evaluation and being impractical for precise core temperature measurement.

Innovation Solution

A circuit and method utilizing multiple temperature-dependent sensor resistors with semiconductor components and diodes or transistors, allowing evaluation of numerous temperature points using a two-pole voltage tap by varying the supply voltage, enabling precise core temperature measurement in cooking appliances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple temperature-dependent resistances are measured using prior art circuits, then temperature measurement capability is improved, but the complexity of the evaluation line increases (requiring multi-pole lines)

Engineering Contradiction:
Improvetemperature measurement capabilityVSAvoidevaluation line complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes a single two-pole line perform multiple functions by sequentially measuring different temperature-dependent resistances. The control unit switches between different sensor combinations, allowing one line to evaluate multiple sensors at different times, thereby eliminating the need for separate poles for each sensor while maintaining full measurement capability.

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

Solution Approach 2:

The measurement process uses periodic action by sequentially and alternately measuring different temperature-dependent resistances through time-multiplexed switching. The control unit cycles through different sensor combinations in periodic intervals, enabling multiple measurements to be taken through a single line over time, thus reducing spatial complexity while preserving measurement versatility.

Inventive Principle:
Principle #19Periodic action

2Measurement precision

If temperature sensors are positioned to accurately measure core temperature, then measurement precision is improved, but the risk of incorrect positioning increases

Engineering Contradiction:
Improvecore temperature detection accuracyVSAvoidpositioning reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system uses feedback by continuously monitoring temperature values from multiple sensor positions and comparing them against expected thermal gradients. The control unit analyzes the relationship between measurements from different sensors to verify proper positioning, providing feedback that confirms whether the sensor is correctly placed in the core region or if repositioning is needed.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent merges multiple temperature measurements from different sensor positions into a comprehensive evaluation. By combining data from multiple temperature-dependent resistances that are spatially distributed, the system creates a more robust determination of core temperature that is less sensitive to single-point positioning errors, thereby improving reliability while maintaining precision.

Inventive Principle:
Principle #5Merging (Combining)

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

Enables the evaluation of multiple temperature points with high accuracy and practicality, ensuring correct core temperature detection for cooking processes, reducing the risk of incorrect positioning and improving cooking control.

Implementation Method 1

The invention relates to a circuit for measuring temperature... at least two temperature-dependent sensor resistances

Methodology Applied
Scientific EffectTemperature-dependent resistance: Thermistor

Implementation Method 2

A diode, or in particular a Zener diode or a Schottky diode, which is connected in the reverse direction is advantageously used

Methodology Applied
Scientific EffectDiode conduction: Diode

Data Source

PatentEP3388802B1Switch and method for temperature measurement and temperature sensor
Publication Date: 2020.04.29 E G O ELEKTRO GERAETEBAU GMBH
  • EP3388802B1 patent drawingFigure 1~2
  • EP3388802B1 patent drawingFigure 3~4
  • EP3388802B1 patent drawingFigure 5~7

AI summary

In a circuit for temperature measurement using temperature-dependent sensor resistances, different temperature-dependent sensor resistances can be selected via a change in a supply voltage, and the measurement results can be transmitted via a two-pole connection. At least two unit arrangements of the first type are provided, each having a semiconductor component and a temperature-dependent sensor resistor in series, and at least one unit arrangement of the second type, which is formed by a unit arrangement of the first type and a semiconductor component connected in series. Each second type unit arrangement is connected in parallel with the previous first type unit arrangement. A measuring resistor is connected in series with a first unit arrangement of the first type. A voltage drop across the measuring resistor corresponds to a total current of partial currents, with each partial current flowing through exactly one unit arrangement of the first type or one unit arrangement of the second type.