Electronic Ignition System Thermal Management via Segmentation
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Solution Overview
Problem
Existing electronic ignition systems for endothermic engines face challenges with high working temperatures, sensitivity to electromagnetic noise, and the need for cooling, which affects the reliability and efficiency of the ignition coil and control circuits.
Innovation Solution
The system separates the high voltage switch and ignition coil from the electronic control unit, placing them near the engine head, while the microprocessor and driving circuit are kept in a cooler location, using a bias circuit and low voltage switch to control the high voltage switch, reducing heat dissipation and electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the coil control electronic circuit is mounted in proximity to the ignition coil, then the control is simplified and integrated, but the electronic components cannot withstand the high working temperatures generated by the ignition coil
Solution Approach 1:
The system is divided into two separate modules: an ignition coil module containing the ignition coil and high voltage switch, and an electronic control unit containing the microprocessor and control circuits. This segmentation allows each module to be optimized for its specific thermal and functional requirements, resolving the contradiction between integration and temperature tolerance.
Solution Approach 2:
The temperature-sensitive electronic control components are extracted from the high-temperature ignition coil environment and placed in a separate electronic control unit. This extraction protects the electronic components from thermal damage while maintaining control functionality through electrical connections.
2Device complexity
If the high voltage electronic switch is controlled directly by the microprocessor, then the control is straightforward, but the command signal is sensitive to electromagnetic noises generated by the ignition coil and vehicle system
Solution Approach 1:
A bias circuit and low voltage switch are introduced as intermediary components between the microprocessor and the high voltage electronic switch. The low voltage switch acts as a buffer that isolates the microprocessor from electromagnetic noise while still enabling control of the high voltage switch, thus resolving the noise sensitivity issue.
3Device complexity
If diagnostic signals are managed inside the electronic ignition system, then the monitoring is integrated, but the diagnostic signals are disturbed by electromagnetic emissions
Solution Approach 1:
Diagnostic and monitoring functions are extracted from the high-temperature, high-noise ignition coil environment and relocated to the separate electronic control unit. This extraction ensures that diagnostic signals remain free from electromagnetic interference while maintaining integrated monitoring capability through the existing communication interfaces.
4Temperature
If cooling means are provided for the ignition coil, then the working temperature is reduced, but the system complexity and cost increase
Solution Approach 1:
The electronic control components are extracted from the ignition coil assembly and placed in a separate unit with better thermal management capabilities. This eliminates the need for complex cooling systems within the ignition coil itself, as the heat-generating electronic components are relocated to an environment where heat dissipation is more manageable.
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 reduces temperature-related issues, increases power transfer to the spark plug without increasing heat dissipation, and simplifies the system, reducing the need for cooling and diagnostic arrangements, while maintaining signal integrity and efficiency.
Implementation Method 1
the transfer of energy from the primary winding 121.1 of the ignition coil 121 to its secondary winding 121.2, thus causing a spark across a spark plug 106
Implementation Method 2
the micro-processor 133 provides a command to open the high voltage electronic switch 124 implemented with an IGBT, thus allowing the transfer of energy
Data Source
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AI summary
An electronic ignition system (10) for an endothermic engine is disclosed. The system comprises a coil (21) having a primary winding (21.1) with a first terminal connected to a battery voltage (Vbatt) and with a second terminal and having a secondary winding (21.2) connected to a spark plug (6). The system further comprises a high voltage switch (24) serially connected to the second terminal of the primary winding and having a bias terminal (G1). The system further comprises a low voltage switch (31) serially connected to the high voltage switch and having a control terminal (G2) carrying a voltage signal (Vctrl) to control the opening or closure of the low voltage switch. The system further comprises a bias circuit (23) of the bias terminal of the high voltage switch and comprises a control and driving unit (35) connected to the control terminal of the low voltage switch. The control and driving unit (35) is configured to generate the voltage signal to control the low voltage switch to close the low voltage switch during a charging phase of energy into the primary winding, and to open the low voltage switch during a transfer phase of the energy from the primary winding to the secondary winding. The high voltage switch is configured to be closed when the low voltage switch is closed and to be open when the low voltage switch is open. The bias circuit is a resistor (23-1) connected between a reference voltage value smaller than or equal to the battery voltage and the bias terminal of the high voltage switch.