Drive Circuit Delay Module for Microcontroller Reset Safety
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Solution Overview
Problem
In electric vehicles, unexpected resets of the microcontroller can cause abrupt switching off of relays, leading to safety hazards and premature wear of relay components.
Innovation Solution
A drive circuit with a delay module that outputs a preset duration delay signal to the high-side driver module during a control module reset, maintaining the relay in its previous state and preventing abrupt state changes, thus ensuring safety and simplifying control logic.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a microcontroller directly controls a relay without additional protection circuits, then the control logic is simple, but the system reliability deteriorates due to unexpected resets causing abrupt relay switching
Solution Approach 1:
The delay module is pre-configured with a preset delay time that is greater than or equal to the microcontroller reset time. When the microcontroller outputs a closing control signal, the delay module immediately begins its timing function, preparing to extend the signal duration to cover the reset period, thus preventing abrupt relay switching before the reset even occurs
Solution Approach 2:
The delay module serves as an intermediary component between the microcontroller and the relay. It receives the closing control signal from the microcontroller, processes it by extending the duration through its delay function, and then outputs the extended signal to control the relay. This mediator role isolates the relay from direct microcontroller control, protecting against reset-induced abrupt switching
2Reliability
If the microcontroller reset time is extended to ensure complete reset completion, then the reset reliability improves, but the response time of the control system deteriorates
Solution Approach 1:
The delay module is pre-configured with a preset delay time that is greater than or equal to the microcontroller reset time. When the microcontroller outputs a closing control signal, the delay module immediately begins its timing function, preparing to extend the signal duration to cover the reset period, thus preventing abrupt relay switching before the reset even occurs
Solution Approach 2:
The system dynamically adapts to the microcontroller reset characteristics by using a delay module with a preset delay time that is specifically designed to be greater than or equal to the reset time. This dynamic timing configuration ensures the relay remains stable throughout the reset period without requiring the microcontroller to extend its reset duration
Data Source
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AI summary
Embodiments of this application relate to the field of electricity, and disclose a drive circuit. In some embodiments of this application, the drive circuit includes a high-side driver module and a delay module, the delay module is configured to output a delay signal of preset duration to the high-side driver module in a case that a control module is being reset; and the high-side driver module is configured to: according to the delay signal of preset duration, remain in a first state within the preset duration, the first state being the same as a second state; where the second state is a working state of the high-side driver module before the control module is reset, and the second state includes being on or off. The embodiments can help avoid safety hazards caused by disconnection of a drive signal of the control module.