AC Voltage Interruption Detection Circuit with Class-Based Segmentation
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Solution Overview
Problem
Conventional AC input voltage interruption detection circuits face issues with erroneous determination due to large time constants and capacitive components, leading to incorrect identification of voltage interruptions, especially when the ripple of detected voltage is small, and are not suitable for integration into circuits.
Innovation Solution
The method involves determining the class of a detected voltage using predefined upper and lower limit voltages and detecting interruptions when the class does not change within a predefined time, employing an upper-limit voltage comparator, lower-limit voltage comparator, up/down counter, digital-analog converter, and timer circuit, allowing for configuration as an integrated circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional AC input voltage interruption detection circuits are used with large time constants and capacitive components, then the circuit can detect voltage interruptions, but erroneous determination occurs especially when the ripple of detected voltage is small
Solution Approach 1:
The voltage detection is segmented into multiple classes (first class, second class, third class) based on voltage thresholds. Instead of continuous monitoring, the circuit divides the voltage range into discrete segments and determines interruption based on class transitions, which eliminates errors from small voltage ripples.
Solution Approach 2:
The detection method dynamically transitions between different detection modes. When voltage ripple is large, conventional continuous monitoring is used. When voltage ripple is small, the system switches to class-based discrete detection, adapting the detection strategy to current operating conditions to maintain accuracy.
2Reliability
If conventional detection circuits are used, then voltage interruption can be detected, but the circuit is not suitable for integration into compact circuit forms
Solution Approach 1:
The invention combines multiple detection functions into a single integrated circuit. The class determination circuit, timer circuit, and comparison logic are merged into one unit that can be fully integrated, eliminating the need for separate discrete components while maintaining detection reliability.
Solution Approach 2:
The invention replaces mechanical/discrete circuit components with integrated circuit implementations. The class-based detection method uses digital logic and timer circuits that can be fabricated as integrated circuits, substituting for larger discrete component-based conventional detection circuits.
3Stability of the object's composition
If the detected voltage ripple is small, then the voltage appears stable, but conventional circuits fail to detect actual interruptions correctly
Solution Approach 1:
The timer circuit is pre-configured to monitor for a predetermined time period regardless of voltage ripple magnitude. This preliminary continuous monitoring ensures that even when voltage appears stable with small ripple, the system has already been timing and will detect an interruption if the voltage class does not change within the predetermined time.
Solution Approach 2:
The system uses feedback from the class determination circuit to the timer circuit. When the voltage class remains unchanged, the timer continues counting; when the class changes, the timer is reset. This feedback mechanism ensures reliable detection by continuously monitoring class transitions and comparing against the predetermined time threshold.
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 effectively detects AC input voltage interruptions even with small ripple, preventing erroneous determinations and enabling integration into compact circuit forms, suitable for various power-supply specifications.
Implementation Method 1
an upper-limit voltage comparator circuit that determines that a detected voltage that corresponds to an AC input voltage is higher than an upper-limit reference voltage
Implementation Method 2
a lower-limit voltage comparator circuit that determines that the detected voltage is lower than a lower-limit reference voltage
Implementation Method 3
an up/down counter that performs a count-up operation in accordance with an output result of the upper-limit voltage comparator circuit, and that performs a count-down operation in accordance with an output result of the lower-limit voltage comparator circuit
Implementation Method 4
a digital-analog converter that outputs the upper-limit reference voltage and the lower-limit reference voltage in accordance with a digital value that is outputted by the up/down counter
Implementation Method 5
a timer circuit that is reset by the count-up operation or the count-down operation of the up/down counter
Data Source
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AI summary
A selector circuit selects either a class upper-limit voltage or a class lower-limit voltage as a reference voltage of a comparator. A control logic controls the selector circuit, and generates a count-up signal or a count-down signal in accordance with the output of the comparator. An up/down counter counts up upon reception of the count-up signal from the control logic, and counts down upon reception of the count-down signal. A digital-analog converter outputs the class upper-limit voltage and the class lower-limit voltage in accordance with a digital value that is outputted by the up/down counter. A timer circuit is configured to be reset by the count-up signal from the control logic to the up/down counter.