Half-Bridge Abnormality Detection Circuit With Low Current Draw
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing abnormality detection circuits for motor systems struggle to efficiently detect abnormalities in motor-driven conditions without increasing circuit complexity or current consumption.
Innovation Solution
The proposed abnormality detection circuit utilizes a configuration that includes a series circuit of a switch and a resistor between a motor drive node and a constant voltage node, along with a comparator to compare voltages and detect abnormalities, thereby reducing circuit area and current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional abnormality detection circuits are used to detect motor abnormalities, then abnormality detection capability is provided, but circuit complexity and current consumption increase
Solution Approach 1:
The patent combines the abnormality detection function with existing motor drive circuit components. The detection circuit utilizes the existing switching elements (M1A, M2A, M1B, M2B) and nodes (N1A, N1B) within the motor drive device, merging the detection functionality into the existing drive architecture rather than adding separate dedicated detection hardware.
Solution Approach 2:
The switching elements and circuit nodes serve dual purposes: they function as motor drive components during normal operation and as sensing elements for abnormality detection. The same switching elements used for motor control are utilized to generate detection signals, making the components multi-functional and eliminating the need for separate detection hardware.
2Reliability
If conventional abnormality detection circuits are used to detect motor abnormalities, then abnormality detection capability is provided, but current consumption increases
Solution Approach 1:
The detection function is merged with the motor drive operation, utilizing the same power supply and current paths. The detection circuit shares the power supply voltage node and uses currents already present during motor drive, eliminating the need for separate detection power consumption.
Solution Approach 2:
The motor drive circuit itself provides the signals needed for abnormality detection. The switching elements generate detection signals through their normal operation, and the circuit uses its own internal states (voltage levels, current flow) as detection inputs, making the system self-diagnosing without external detection resources.
3Measurement precision
If detection circuits operate continuously to detect abnormalities, then detection accuracy is maintained, but current consumption increases
Solution Approach 1:
The abnormality detection is performed periodically based on the motor drive cycle rather than continuously. The detection circuit operates during specific phases of the motor drive operation (when switching elements are activated), utilizing the periodic nature of motor control to achieve detection without continuous power consumption.
Solution Approach 2:
The detection circuit is designed to detect abnormalities during the motor drive operation itself, using the drive signals as detection triggers. By performing detection during the necessary motor operation periods, the system ensures detection accuracy is maintained when needed while avoiding unnecessary detection during idle periods.
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 configuration enables efficient detection of abnormalities in motor systems, even when the motor is not driven, while minimizing current consumption and circuit area, thus enhancing the reliability and efficiency of motor drive devices.
Implementation Method 1
a first comparator configured so as to compare a voltage corresponding to a voltage of the first node with a first reference voltage
Data Source
AI summary
This abnormality detection circuit is configured so as to detect abnormality of a first half bridge including a first switching element and a second switching element. The abnormality detection circuit includes: a series circuit of a first switch and a first resistor provided between a first node which is a connection node for the first switching element and the second switching element and a second node configured so as to have a first constant voltage applied thereto; and a first comparator configured so as to compare a first reference voltage and a voltage corresponding to the voltage of the first node.