Switching Element Over-Current Detection With Temperature Compensation
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Solution Overview
Problem
Conventional over-current protection apparatuses for switching elements are costly and space-consuming due to the use of operational amplifiers, which are not necessary for effective over-current detection.
Innovation Solution
An over-current detecting apparatus that utilizes a comparator circuit, a current converting element, and resistors to convert temperature detecting voltage into a current, eliminating the need for an operational amplifier by adjusting resistance values to match temperature characteristics, thereby reducing costs and space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an operational amplifier is used in the over-current protection circuit, then the detection accuracy and temperature compensation are improved, but the cost and device area increase
Solution Approach 1:
The patent extracts the essential function of the operational amplifier (comparing voltages and providing temperature compensation) and implements it using simpler, separate components: a comparator circuit, a current converting element, and resistors. This removes the need for the complex operational amplifier while maintaining the core functionality of accurate over-current detection with temperature compensation.
Solution Approach 2:
The patent segments the operational amplifier's functions into separate components: the comparator circuit handles voltage comparison, the current converting element performs temperature compensation by converting temperature voltage to compensation current, and resistors provide scaling. This segmentation allows each component to be optimized independently and reduces overall complexity and cost.
2Measurement precision
If an operational amplifier is used in the over-current protection circuit, then the detection accuracy and temperature compensation are improved, but the device area increases
Solution Approach 1:
By segmenting the operational amplifier's functions into separate discrete components (comparator, current converting element, resistors), the circuit can be laid out more efficiently on the chip. Each component occupies minimal space and can be positioned optimally, reducing the total device area compared to a single operational amplifier block.
Solution Approach 2:
The patent removes the operational amplifier component entirely and replaces it with simpler elements that occupy less silicon area. The comparator circuit and current converting element are fundamentally simpler structures that require less fabrication space while achieving the same functional goals.
3Stability of the object's composition
If conventional over-current protection circuit is used, then the temperature characteristic compensation is achieved, but the cost and space requirements increase
Solution Approach 1:
The patent replaces the expensive operational amplifier with cheaper alternative components: a comparator circuit, a current converting element, and resistors. These components are less expensive to manufacture and integrate, reducing the overall cost of the over-current protection circuit while maintaining temperature compensation functionality.
Solution Approach 2:
The patent changes the operational parameters and component types from high-performance operational amplifiers to simpler comparator-based circuitry. By adjusting the parameters of the resistors and current converting element, the circuit achieves the same temperature compensation effect at lower cost and complexity.
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 allows for a compact and cost-effective over-current detection system that is independent of switching element temperature, reducing the impact of temperature changes on detection accuracy.
Implementation Method 1
The current converting element converts a voltage of a temperature detecting element that detects a temperature of the switching element into a current corresponding to the voltage of the temperature detecting element
Data Source
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AI summary
An over-current detecting apparatus for a switching element (1) includes a reference power source (7), a comparator circuit (8), a current converting element (6), a first resistor (R3), and a second resistor (R2). The comparator circuit (8) includes a first input terminal that receives a voltage corresponding to a current flowing in the switching element and a second input terminal that receives a reference voltage supplied from the reference power source (7). The current converting element (6) converts a voltage of a temperature detecting element (4) that detects a temperature of the switching element (1) into a current corresponding to the voltage of the temperature detecting element (4). The first resistor (R3) is connected in series to a reference power supply side of the second input terminal of the comparator circuit (8). The second resistor (R2) is connected in series to a ground side of the second input terminal of the comparator circuit (8).