Electromagnetic Load Circuit Diagnosis for FET Layer Short Detection
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Solution Overview
Problem
Existing electromagnetic load circuit failure diagnosis devices are unable to accurately detect layer short-circuits in switch elements, particularly in the case of a FET, as they do not distinguish between a layer short-circuit and other types of failures, leading to difficulties in precise failure identification in internal-combustion engine injector circuits.
Innovation Solution
A failure diagnosis device that detects layer short-circuits by monitoring the number of times an electrical value exceeds a predetermined threshold, measuring the time for a current to reach a threshold, checking voltage thresholds, and counting on/off operations of switch element driving signals, allowing for precise diagnosis of layer short-circuit failures in electromagnetic load circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing electromagnetic load circuit failure diagnosis devices are used, then general failure detection is possible, but layer short-circuit failures in switch elements cannot be accurately detected
Solution Approach 1:
The patent segments the failure detection process into multiple distinct measurement phases: initial current rise detection, holding current detection, and voltage threshold comparisons. By dividing the diagnosis into separate detectable events, the system can identify layer short-circuits that would otherwise be indistinguishable from other failure modes.
Solution Approach 2:
The patent performs preliminary diagnostic actions by monitoring current thresholds and voltage levels during normal operation phases before actual failure occurs. The system establishes baseline expectations for current rise times and holding currents, enabling early detection of layer short-circuit conditions that deviate from normal behavior.
2Measurement precision
If multiple detection methods are implemented to improve diagnosis accuracy, then layer short-circuit detection capability is enhanced, but device complexity increases
Solution Approach 1:
The patent implements multi-functional detection circuits that serve multiple purposes: the same current detection circuit monitors both initial current rise and holding current levels, while voltage detection circuits perform both threshold comparisons and normal operation monitoring. This universal approach enables accurate layer short-circuit detection without requiring entirely separate diagnostic hardware.
Solution Approach 2:
The patent introduces intermediary signal processing elements that mediate between raw sensor inputs and final failure determination. Threshold comparison circuits and logic units act as intermediaries, translating multiple physical measurements (current, voltage, time) into a unified failure diagnosis output, thereby managing complexity through structured signal integration.
Data Source
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AI summary
A layer short-circuit of a switch element such as a FET included in an electromagnetic load circuit is detected to accurately perform a failure diagnosis of the electromagnetic load circuit. A failure diagnosis circuit 101 is provided which detects a layer short-circuit in which a high-side switch element, a low-side switch element, or an electromagnetic load itself short-circuits with a power supply voltage terminal or a ground in a state of having a predetermined impedance to perform a failure diagnosis.