H-Bridge Motor Drive Fault Detection Without Constant Current Sources
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Solution Overview
Problem
Existing motor drive devices using H-bridge circuits require constant current sources for abnormality detection, leading to increased circuit size and power consumption during detection operations.
Innovation Solution
The motor drive device incorporates an abnormality detection unit with voltage divider resistors and switches to detect short circuits and open circuits in the transistors without the need for constant current sources, thereby reducing circuit size and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If constant current sources are used for abnormality detection, then detection function is achieved, but circuit size increases
Solution Approach 1:
The patent extracts and eliminates the constant current source component from the abnormality detection circuit. Instead of using a dedicated constant current source, the invention uses the existing power supply voltage and ground potential combined with voltage divider resistors to achieve the detection function, thereby removing the problematic component that increased circuit size.
Solution Approach 2:
The patent makes the power supply voltage and ground potential serve multiple functions. These existing voltage references are not only used for normal motor operation but also for abnormality detection, eliminating the need for separate detection components and reducing overall circuit size.
2Reliability
If constant current sources are used for abnormality detection, then detection function is achieved, but power consumption increases
Solution Approach 1:
The patent removes the constant current source that caused excessive power consumption during detection operations. By replacing it with a voltage divider-based detection method using existing power supply voltages, the detection function is maintained while power consumption is significantly reduced.
Solution Approach 2:
The patent enables the power supply system to serve its own detection needs. The existing power supply voltage and ground potential are used to perform abnormality detection without requiring additional power-consuming components, allowing the system to self-diagnose with minimal energy expenditure.
3Ease of operation
If H-bridge circuit is used for motor control, then motor drive function is achieved, but abnormality detection requires additional components
Solution Approach 1:
The patent makes the H-bridge circuit components serve dual purposes. The same transistors and voltage nodes used for motor control are also utilized for abnormality detection, eliminating the need for separate detection circuits and reducing overall device complexity.
Solution Approach 2:
The patent merges the motor control function and abnormality detection function into a single integrated system. By combining these functions and using shared components like voltage divider resistors and existing power supply nodes, the detection circuit complexity is reduced while maintaining full motor drive capability.
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 solution allows for efficient abnormality detection in the motor drive device without increasing circuit size, while also reducing power consumption during detection operations.
Implementation Method 1
a first voltage divider resistor R1 connected between the first external terminal DRN and the second external terminal SH1; a second voltage divider resistor R2 connected between the second external terminal SH1 and an application end of ground potential
Data Source
AI summary
In the present invention, an abnormality detection unit comprises first voltage divider resistors connected between a first external terminal and a second external terminal, second voltage divider resistors connected between the second external terminal and a ground potential application end, first switches connected between the first external terminal and the second external terminal, second switches connected between the second external terminal and the ground potential application end, first comparators configured to compare the voltage between the first external terminal and the second external terminal with first reference voltages, and second comparators configured to compare the voltage between the second external terminal and the ground potential application end with second reference voltages.