Humidity Sensor PWM Resistance Variator Voltage Drop
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Solution Overview
Problem
Existing humidity measuring devices face challenges in reducing voltage drop and increasing the voltage range of humidity signals, which affects the accuracy and efficiency of humidity measurement.
Innovation Solution
A humidity measuring system that includes a low-consumption humidity sensor and electronic stages with a resistance variator branch controlled by a PWM signal, allowing the equivalent resistance to vary based on humidity, thereby adjusting the voltage drop and increasing the voltage range of the humidity signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a conventional humidity sensor is used, then the device structure is simple, but the voltage drop is high and the voltage range of humidity signal is limited
Solution Approach 1:
The patent applies the dynamics principle by making the resistance variator branch adjustable through PWM signal control. The equivalent resistance can dynamically change based on the duty cycle of the PWM signal, allowing the system to adaptively optimize the voltage range of humidity signal according to different measurement requirements, thus resolving the contradiction between simple structure and sufficient voltage range.
Solution Approach 2:
The patent changes the resistance parameter through the resistance variator branch controlled by PWM signal. By varying the duty cycle of the PWM signal, the equivalent resistance changes, which directly affects the voltage division ratio and thereby expands the voltage range of the humidity signal output, solving the limitation of fixed voltage range in conventional sensors.
2Device complexity
If a conventional humidity sensor is used, then the device structure is simple, but the measurement accuracy is insufficient
Solution Approach 1:
The dynamics principle is applied by enabling real-time adjustment of the resistance variator branch through PWM control. This allows the system to dynamically optimize the voltage signal characteristics for different humidity levels, improving the linearity and resolution of the measurement signal, thereby enhancing measurement accuracy without significantly complicating the device structure.
Solution Approach 2:
The patent implements feedback control where the PWM signal duty cycle is adjusted based on the measured humidity value to optimize the output voltage range. This feedback mechanism ensures that the measurement signal remains within the optimal voltage range for the ADC converter, improving measurement precision while maintaining a relatively simple device structure.
3Measurement precision
If the voltage range of humidity signal is increased, then the measurement accuracy is improved, but the device complexity increases
Solution Approach 1:
The resistance variator branch serves multiple functions: it acts as a signal conditioning element, a voltage range adjuster, and a calibration mechanism. By integrating these functions into a single adjustable component controlled by PWM signal, the patent achieves improved measurement accuracy without proportionally increasing device complexity.
Solution Approach 2:
The resistance variator branch acts as an intermediary element between the humidity sensor and the ADC converter. It mediates the signal transformation and optimization, allowing the system to achieve accurate measurements across different voltage ranges without requiring multiple dedicated circuits, thus balancing measurement precision and device complexity.
4Loss of energy
If a low-consumption humidity sensor is used, then the voltage drop is reduced, but the device requires additional electronic stages
Solution Approach 1:
The patent merges the low-consumption sensor with the resistance variator branch into an integrated measurement system. The resistance variator branch is combined with the sensor output circuit, allowing the same electronic stages to serve both signal conditioning and resistance adjustment functions, thereby reducing overall device complexity despite the addition of functional elements.
Solution Approach 2:
The electronic stages in the patent perform multiple functions: they amplify the sensor signal, adjust the voltage range through the resistance variator, and interface with the ADC converter. This multi-functionality reduces the need for separate dedicated circuits, balancing the requirement for low voltage drop with acceptable device complexity.
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 system effectively reduces voltage drop and increases the voltage range of the humidity signal, enabling more accurate and efficient humidity measurement without requiring significant changes to the electrical circuit of the measuring instrument.
Implementation Method 1
provides a signal PWM whose DC varies as a function of the measured humidity
Implementation Method 2
This voltage drop decrease allows an increase in the voltage range of the humidity measuring signal
Implementation Method 3
a humidity sensor 6 configured to measure humidity and provide a signal PWM, whose DC varies as a function of the measured humidity
Data Source
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AI summary
Humidity measuring system comprising a humidity measuring device (2)(42)(52) and an electronic measuring apparatus (3). The electronic measuring apparatus is provided with a first terminal (3a) and with a processing module (5) that is configured to determine the humidity based on a measurement voltage (VS) on the first terminal (3a). The humidity measuring device (2)(42)(52) comprises a humidity sensor (6) that is configured to provide an electrical pulse signal (PWM) and to modulate the duty cycle (DC) of the electrical pulse signal (PWM) based on the detected/measured humidity, and an electronic stage (8) (54) that receives the electrical pulse signal (PWM) and is configured to vary the measurement voltage (VS) on the first terminal (3a) of the measuring apparatus (3) based on the duty cycle (DC) of the electrical pulse signal (PWM).