Closed-Loop Current Sensor Mode Control for Low Heat and Standby Power
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Solution Overview
Problem
Existing close-loop current sensors face issues with overheating, high standby power consumption, and a limited full scale due to fluctuating power supply voltages.
Innovation Solution
A low-power intelligent current sensor is developed, incorporating a magnetic core, secondary coil, magnetic sensor, and a current detection circuit with a microcontroller, temperature detection module, and power supply module. The sensor features multiple operating modes (normal, low-power, standby, and sleep) controlled by the microcontroller to manage power consumption and temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current is supplied to generate magnetic field on secondary coil to balance primary current magnetic field, then high-precision measurement is achieved, but heat is generated and temperature rises
Solution Approach 1:
The patent implements periodic action by controlling the secondary coil to operate in pulsed mode rather than continuous operation. The microcontroller activates the secondary coil only during measurement intervals and deactivates it during idle periods, reducing continuous heat generation while maintaining measurement precision when needed. This is achieved through the working mode control module that switches between different operational states.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the working current of the secondary coil based on the detected primary current magnitude. When primary current is small, the secondary coil operates at lower current to reduce heat; when primary current is large, the secondary coil increases current to maintain measurement accuracy. This adaptive parameter adjustment resolves the contradiction between precision and heat generation.
2Temperature
If thermally conductive glue is used to dissipate heat, then temperature control is improved, but production cost, weight, and environmental impact increase
Solution Approach 1:
The patent extracts and eliminates the thermally conductive glue from the system by implementing a glue-free structural design. Instead of relying on thermal paste or conductive adhesive to transfer heat, the design uses direct thermal pathways through the magnetic core and housing structure, thereby removing the problematic material while maintaining temperature control functionality.
Solution Approach 2:
The patent enables self-service heat dissipation by designing the magnetic core and housing to inherently conduct heat away from the secondary coil through their structural geometry and material properties. The magnetic core itself acts as a heat sink, and the housing provides thermal pathways, eliminating the need for external thermal management materials like conductive glue.
3Reliability
If current is continuously supplied to secondary coil, then measurement function is maintained, but standby power consumption is high
Solution Approach 1:
The patent implements periodic action by controlling the secondary coil to operate in pulsed mode rather than continuous operation. The microcontroller activates the secondary coil only during measurement intervals and deactivates it during idle periods, reducing continuous heat generation while maintaining measurement precision when needed. This is achieved through the working mode control module that switches between different operational states.
Solution Approach 2:
The patent applies dynamics by making the secondary coil's operational state variable rather than fixed. The system dynamically transitions between active measurement mode, standby mode, and sleep mode based on real-time conditions. The microcontroller continuously monitors the primary current and adjusts the secondary coil's operation accordingly, enabling the system to adapt its power consumption to actual measurement needs.
4Adaptability or versatility
If power supply voltage fluctuates within large range, then adaptability is improved, but full scale of sensor is limited by lower voltage limit
Solution Approach 1:
The patent applies parameter changes by implementing a voltage regulation mechanism that converts fluctuating input voltages into a stable operating voltage for the secondary coil. The power supply module includes voltage regulation circuitry that adjusts its output based on the input voltage level, ensuring that the secondary coil receives consistent voltage regardless of input variations. This allows the sensor to maintain its full scale measurement capability across a wide range of power supply voltages.
Solution Approach 2:
The patent implements feedback by using the microcontroller to monitor the power supply voltage and dynamically adjust the secondary coil's operating parameters accordingly. When the input voltage drops, the system compensates by adjusting the duty cycle or current amplification to maintain the required magnetic field strength for full-scale measurements. This feedback mechanism ensures that voltage fluctuations do not limit the sensor's measurement range.
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 reduces heat generation and standby power consumption, extends the full scale of the sensor by regulating power supply voltage, and enables intelligent control of the current sensor through the microcontroller.
Implementation Method 1
the magnetic sensor converts an induced magnetic field signal into an electrical signal
Implementation Method 2
drive a secondary compensation coil to generate a magnetic field that is opposite to and has the same magnitude as a primary current magnetic field
Data Source
Figure 1~3
Figure 4~5
Figure 6~7
AI summary
The present disclosure discloses a low-power intelligent current sensor and a control method of its operating mode. The sensor includes a magnetic core, a secondary coil wound around the magnetic core, a magnetic sensor disposed in the magnetic core, and a current detection circuit, the current detection circuit including a power supply module, a drive module, a microcontroller, a temperature detection module, and a signal input/output interface module. The signal output terminal of the magnetic sensor is connected to a signal input terminal of the drive module. The drive module is connected to each of two ends of the secondary coil. The microcontroller is in signal connection to each of the power supply module, the drive module, the temperature detection module, and the signal input/output interface module. The power supply module is connected to each of the drive module, the microcontroller, the temperature detection module, and the signal input/output interface module. The present disclosure reduces heat generation and standby power consumption of a close-loop current sensor, and regulates the power supply voltage to a proper value, to increase the full scale of the sensor.