Comparator-Based Circuit Breaker for Overcurrent Type Detection
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Solution Overview
Problem
Current circuit breakers fail to distinguish between types of overcurrents, such as surge, short-circuit, and fault overcurrents, leading to inadequate protection, especially in scenarios where surge overcurrents are not properly switched off, and existing solutions that use ADC and MCU for differentiation are slow, resulting in delayed protection.
Innovation Solution
A circuit breaker design that employs a control circuit with comparators to differentiate between overcurrent types by comparing loop current and voltage thresholds, allowing for microsecond-level protection without analyzing waveforms, using a switch unit controlled by a comparator-based logic to determine the appropriate action based on preset thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ADC combined with MCU is used to observe current features and distinguish overcurrent types, then the type of overcurrent can be distinguished, but it takes more than several milliseconds and the circuit protection cannot be realized quickly
Solution Approach 1:
The patent replaces the software-based ADC+MCU system with a hardware-based comparator circuit system. The comparators directly compare current and voltage signals in hardware, eliminating the need for software processing and waveform analysis, thus achieving microsecond-level response while maintaining overcurrent type distinction capability
Solution Approach 2:
The patent uses multiple comparators to create parallel comparison paths for different overcurrent type detection. Each comparator copies and compares specific signal combinations (current alone, current+voltage, etc.) to determine overcurrent types, enabling simultaneous multi-parameter detection without sequential processing delays
2Speed
If circuit breaker switches on/off only according to whether loop current exceeds preset current threshold, then the switching action is simple and fast, but the type of overcurrent cannot be distinguished and thus not switching off the main loop in the case of surge overcurrent cannot be realized
Solution Approach 1:
The patent segments the overcurrent detection function into multiple parallel comparator circuits, each dedicated to detecting specific overcurrent types by comparing different signal combinations. This segmentation allows simultaneous detection of multiple overcurrent types without sequential processing, maintaining fast response while achieving precise type distinction
Solution Approach 2:
The patent adds a voltage comparison dimension to the traditional current-only threshold comparison. By introducing voltage as an additional detection dimension and combining it with current comparisons, the system can distinguish between surge overcurrent (high voltage present) and short-circuit overcurrent (low voltage present) while maintaining simple hardware architecture
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
Enables rapid and accurate differentiation of overcurrent types, ensuring timely and appropriate switching actions, thereby providing reliable microsecond-level overcurrent protection without relying on microcontroller analysis.
Implementation Method 1
A control circuit comprising a comparator, the control circuit is configured for comparing the loop current with a preset short-circuit current threshold, comparing the loop current with a preset surge current threshold
Implementation Method 2
comparing the loop voltage with a preset surge voltage threshold by means of the comparator
Implementation Method 3
A switch unit arranged between the input side and the output side for turning on and turning off the load loop
Implementation Method 4
A current detection unit for detecting a loop current of the load loop
Implementation Method 5
A voltage detection unit for detecting a loop voltage between the first line and the second line
Data Source
AI summary
A circuit breaker is disclosed, including: an input side including a first input end and a second input end for respectively connecting to a first line and a second line of a power supply; an output side including a first output end and a second output end for respectively connecting two ends of an electric load to form a load loop; a switch unit arranged between the input side and the output side for turning on and turning off the load loop; a current detection unit for detecting a loop current of the load loop; a voltage detection unit for detecting a loop voltage between the first line and the second line; a control circuit including at least one comparator, the control circuit is configured for controlling whether to turn off the switch unit according to comparison results.