Magnetic Sensor Offset Cancellation via Periodic Switching
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Solution Overview
Problem
Conventional magnetic sensor devices face challenges in achieving high-speed and precise detection of magnetic field intensity due to offset voltages from magnetoelectric conversion elements and amplifiers, leading to reduced accuracy and increased circuit complexity.
Innovation Solution
A magnetic sensor device utilizing a simple circuit configuration with multiple differential input pairs, capacitors, and strategically timed switch operations to cancel out offset components, enabling high-speed and precise magnetic field intensity detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional magnetic sensor devices use offset voltage compensation circuits, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies periodic action by implementing a detection operation that alternates between a first detection state and a second detection state. During each state, different terminal connections are activated to the magnetoelectric conversion element, enabling periodic measurement cycles that facilitate offset voltage compensation through differential measurement techniques.
Solution Approach 2:
The patent implements preliminary action by performing offset voltage compensation measurements in advance during the detection operation cycles. The system预先 establishes reference measurements during specific phases (first or second detection states) that are then used to compensate for offset voltages in subsequent magnetic field intensity measurements, eliminating the need for complex continuous compensation circuits.
2Measurement precision
If conventional magnetic sensor devices use multiple detection phases for offset compensation, then measurement precision is improved, but response speed decreases
Solution Approach 1:
The patent maintains continuity of useful action by ensuring that the detection operation continuously alternates between the first and second detection states without idle periods. The switch circuit and terminal connections are designed to enable seamless transitions between measurement phases, allowing offset compensation and magnetic field detection to occur in an uninterrupted continuous cycle, thereby maintaining high response speed while achieving precise measurements.
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 allows for highly precise and rapid response to magnetic field changes with minimal additional circuitry, effectively removing offset components and enhancing detection accuracy.
Implementation Method 1
a magnetoelectric conversion element (such as Hall element) outputs a voltage corresponding to (typically, substantially proportional to) magnetic field intensity
Data Source
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AI summary
Provided is a sensor device capable of removing the influence of each offset voltage of a sensor element, a differential amplifier, and an amplifier of the sensor device, to thereby detect a physical quantity with high precision and respond to high-speed operation. The sensor device includes: a switch circuit connected to a first terminal pair and a second terminal pair of the sensor element, for controlling switching of the terminal pairs and outputting signal voltages; a differential amplifier including a first input terminal and a second input terminal connected to a first output terminal and a second output terminal of the switch circuit, respectively, for outputting a result obtained by amplifying a difference of the signal voltages; an amplifier including at least two differential input pairs, one of which inputs the differential signal output from the differential amplifier, and at least one of which inputs a reference signal corresponding to a physical quantity to be detected; and a detection voltage setting circuit for outputting the reference signal to the amplifier. Switching of the switch circuit provides a first detection state and a second detection state, and detection is performed in one first detection state and one second detection state.