Cooktop Temperature Sensor Compensation for Dark Current
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Solution Overview
Problem
Existing cooktops with infrared sensors for temperature measurement face accuracy issues due to dark current from photodiodes, which increases exponentially with temperature, leading to measurement errors above 75°C and the need for complex and costly optical fiber setups to position photodiodes outside high-temperature areas.
Innovation Solution
A cooktop apparatus with a temperature sensor unit and an amplifier unit, including a compensation unit that partially compensates for temperature influences on the measurement signal, allowing the photodiode to be positioned directly in high-temperature regions without the need for optical fibers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If photodiodes are positioned directly in high-temperature cooking regions, then measurement accuracy is improved and production is simplified, but dark current increases exponentially causing measurement errors
Solution Approach 1:
The patent applies parameter changes by introducing a compensation unit that dynamically adjusts for temperature influences on the photodiode's conversion and amplification processes. This allows the photodiode to operate directly in high-temperature regions while maintaining measurement accuracy through real-time parameter compensation for dark current and operational amplifier temperature effects.
2Object-generated harmful factors
If photodiodes are positioned in cooler regions below or adjacent to the cooktop plate, then dark current is reduced, but the system becomes complex requiring optical fibers to conduct infrared radiation
Solution Approach 1:
The patent extracts the harmful temperature influence from the measurement system by positioning the photodiode directly in the high-temperature cooking region and using a compensation unit to mathematically extract and correct for the dark current effect, eliminating the need for optical fibers and cooler region positioning.
Solution Approach 2:
The patent replaces the mechanical/optical system of optical fibers with an electronic compensation system. Instead of physically transporting infrared radiation through optical fibers to a cooler region, the system uses electronic signal processing and parameter compensation to correct temperature-induced measurement errors.
3Ease of operation
If conventional operational amplifiers are used to amplify photocurrent, then measurement signals can be evaluated, but temperature-related influences cause cumulative offset voltage reducing measurement accuracy
Solution Approach 1:
The compensation unit operates as a feedback mechanism that continuously monitors temperature influences on the amplification process and adjusts the measurement signal accordingly. This feedback loop compensates for cumulative offset voltage caused by temperature-related amplifier drift, maintaining measurement accuracy across varying temperature conditions.
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 solution significantly improves measuring accuracy, reduces production complexity and costs, and enables accurate temperature measurements even at high temperatures by minimizing temperature-related interference.
Implementation Method 1
at least one photodiode (14) provided for the purpose of detecting incident infrared radiation and converting it into a measurement signal
Data Source
AI summary
A household appliance apparatus, in particular a cooktop apparatus, includes a temperature sensor unit which includes a photodiode designed to detect incident infrared radiation and to convert the incident infrared radiation into a measurement signal. The measurement signal is amplified by an amplifier of an amplifier unit. A compensation unit at least partially compensates for a temperature influence as the infrared radiation is converted into the measurement signal and/or the measurement signal is amplified.