LC Sensor Peak Detector Interface for Low-Power Metal Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LC sensor interfacing techniques face challenges in reducing power consumption and silicon area usage, particularly in battery-powered systems, due to the need for high-power dedicated components like fast comparators and analog-to-digital converters to handle oscillations and detect metallic objects effectively.
Innovation Solution
The implementation of a system that uses an analog peak detector with a diode and storage capacitor to determine the peak voltage of LC sensor oscillations, coupled with a control unit that selectively activates and deactivates the starter and detection means to minimize power consumption, allowing for efficient interfacing with microcontrollers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If fast comparators and analog-to-digital converters are used to handle oscillations and detect metallic objects, then detection speed and accuracy are improved, but power consumption increases
Solution Approach 1:
The patent extracts only the essential information needed for detection by using a peak detector to capture the maximum voltage value of the oscillation signal. This eliminates the need for continuous high-speed sampling and processing of the entire oscillation waveform, thereby reducing power consumption while maintaining detection accuracy.
Solution Approach 2:
The system employs periodic measurement cycles where the LC sensor is excited, the oscillation occurs, and the peak detector captures the signal at specific intervals. This periodic operation allows the control unit to remain in a low-power state between measurements, significantly reducing average power consumption while maintaining effective detection capability.
2Reliability
If dedicated on-chip components are used for LC sensor interfacing, then reliability and performance are improved, but silicon area usage increases
Solution Approach 1:
The control unit is designed to perform multiple functions: it generates the excitation signal for the LC sensor, processes the oscillation signal through the peak detector, and performs the detection logic. This multi-functional approach eliminates the need for separate dedicated components, reducing silicon area while maintaining system reliability through integrated design.
Solution Approach 2:
The patent combines the excitation generation, signal processing, and detection functions into a single control unit. The peak detector is integrated with the control unit, and the LC sensor interfacing is handled through the same control logic, thereby reducing the total component count and silicon area required.
3Reliability
If continuous monitoring of LC sensor oscillations is performed, then detection reliability is improved, but power consumption increases
Solution Approach 1:
The peak detector is pre-configured to capture the maximum voltage value of the oscillation signal during the excitation phase. By preparing the detection mechanism in advance and capturing the critical peak value during the brief oscillation window, the system ensures reliable detection without requiring continuous monitoring afterward, thus reducing power consumption.
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 reduces the required dedicated on-chip components and power consumption, enabling efficient handling of LC sensors while supporting a wide range of sensor sizes and frequencies, thus enhancing the flexibility and battery life of battery-powered systems.
Implementation Method 1
LC sensors may be used as electronic proximity sensors which are able to detect the presence of a conductive target
Implementation Method 2
the LC sensor comprises an inductor L and a capacitor C, which form a resonant circuit also called tank circuit
Implementation Method 3
an analog peak detector is used in order to determine a signal being indicative of a peak voltage of the oscillation of the LC sensor. The peak detector comprises a diode and a storage capacitor
Implementation Method 4
The peak detector comprises a diode and a storage capacitor, wherein the anode of the diode may be connected to the LC sensor and the cathode of said diode is connected to a first terminal of the storage capacitor
Data Source
Figure 1~2b
Figure 3a~3b
Figure 4~5b
AI summary
A system for interfacing an LC sensor (10) is described. The system comprises means (206) configured to selectively start an oscillation of the LC sensor (10). The system comprises also an analog peak detector (280) configured to determine a signal (Vpeak) being indicative of a peak voltage of the oscillation of the LC sensor (10) and detection means (208, 230) configured to determine the state of the LC sensor (10) as a function of the signal (Vpeak) determined by the analog peak detector (280).