Hall Sensor Offset Correction via Spinning Current Segmentation
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Solution Overview
Problem
Current Hall sensor systems without a magnetic core face challenges in achieving accurate and fast current or magnetic field measurements due to high sensor offset and limited measuring frequency, which is exacerbated by the need for complex calibration and increased effort and costs when detecting short-circuit currents.
Innovation Solution
The method involves operating Hall sensors with spinning current technology, converting sensor signals into digital signals, and combining them over different time periods to calculate and correct for offset, allowing for fast and accurate measurements without increasing circuit complexity or requiring additional analogue components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If Hall sensors without a magnetic core are used to reduce volume and cost, then the device size and cost are reduced, but the sensor offset becomes high relative to the signal magnitude
Solution Approach 1:
The patent applies preliminary action by performing offset correction before final measurement. The system integrates sensor signals over a first period to calculate offset values, then uses these pre-calculated offsets to correct subsequent fast measurements. This preliminary offset characterization enables rapid correction without adding physical components, resolving the contradiction between using compact coreless sensors and maintaining measurement accuracy.
2Measurement precision
If the spinning current principle is used to suppress offset, then the offset component is reduced, but the measuring frequency is limited due to transient oscillation processes during switching
Solution Approach 1:
The patent segments the measurement process into two distinct parts: a slow integration phase for offset calculation and a fast measurement phase for current detection. By separating these functions in time rather than requiring simultaneous operation, the system can use the spinning current principle for offset suppression while achieving high measuring frequencies for actual current measurement, resolving the contradiction between offset suppression and measuring speed.
Solution Approach 2:
The system employs periodic action by alternating between slow integration periods for offset calculation and fast measurement periods for current detection. This periodic switching allows the spinning current phases to complete their offset-suppression function during integration periods while enabling high-frequency measurements during fast measurement periods, thus resolving the frequency limitation imposed by continuous spinning current operation.
3Loss of time
If measurement cycles are shortened to detect short-circuit currents quickly, then the response time is reduced, but the signal quality deteriorates due to noise from settling time
Solution Approach 1:
The patent applies preliminary action by pre-calculating offset values during slow integration periods before fast measurement cycles begin. This preliminary offset characterization allows the system to use extremely short measurement cycles for short-circuit detection without sacrificing signal quality, because the offset correction is already prepared and does not require long settling times during the critical fast measurement phase.
4Measurement precision
If precise measurements are provided for regulation with long measurement cycles, then the measurement accuracy is improved, but the detection of short-circuit currents is delayed
Solution Approach 1:
The patent segments measurement functions into two parallel paths: slow integration for high-precision offset calculation and fast measurement for rapid current detection. This segmentation allows the system to maintain high measurement accuracy through careful offset characterization while simultaneously providing rapid response for short-circuit detection, resolving the contradiction between precision and speed by assigning different functions to different time scales.
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 approach enables precise and rapid current or magnetic field measurements with reduced thermal drift and offset correction, enabling detection of excess currents quickly while maintaining measurement accuracy and reducing the need for elaborate calibrations.
Implementation Method 1
at least one Hall sensor, which is operated with spinning current technology
Data Source
AI summary
The present invention relates to a method and a device for measuring currents or magnetic fields using at least one Hall sensor, which is operated with spinning current technology. In addition to first sample values for calculating a spinning current measurement value (6), second sample values are formed from the digitally converted sensor signals (1) of the Hall sensor in the method. The second sample values are formed over shorter periods of time (9) and are corrected with an offset, which is calculated from the spinning current measurement value (6) and the first sample values. In addition to the precise spinning current measurement value (6), fast offset-corrected measurement values (10) of the magnetic field or current are obtained using the method and the associated device, without elaborate calibration or additional analog circuitry expenses.