Multi-Charge Ignition Coil Control for Diode Voltage Protection
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Solution Overview
Problem
Existing ignition systems for lean air-fuel mixtures require high energy ignition sources, leading to the use of large, high energy single spark ignition coils with limited spark duration and energy output, and direct measurement of diode voltages in epoxy resin locations, which are prone to failure and require additional production steps.
Innovation Solution
A multi-charge ignition system with a spark plug control unit that controls two coil stages, using transformers and switches to manage voltage measurements indirectly through collector terminals of IGBTs, allowing for efficient voltage regulation and protection of diodes without direct epoxy placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If direct measurement of diode voltage is performed via resistors in epoxy resin, then voltage monitoring is achieved, but reliability deteriorates due to failure risk and additional production complexity
Solution Approach 1:
The patent uses the collector terminal of the IGBT as an intermediary measurement point. Instead of directly measuring diode voltage through resistors in epoxy, the system measures the voltage at the IGBT collector terminal, which indirectly provides the necessary information for diode protection while eliminating the need for additional resistors and epoxy encapsulation.
2Use of energy by moving object
If large high energy single spark ignition coils are used, then sufficient ignition energy is provided, but spark duration is limited and system size increases
Solution Approach 1:
The patent implements multi-charge ignition systems that produce a fast sequence of individual sparks through periodic charging and discharging of multiple coil stages. This periodic action creates a long quasi-continuous spark with extended duration while maintaining high energy output, overcoming the limitation of single spark systems.
3Duration of action of moving object
If multi-charge ignition systems are used, then spark duration is extended and system size is reduced, but diode protection becomes more complex
Solution Approach 1:
The IGBT collector terminal serves multiple functions: it acts as a switching element for coil stage control and simultaneously provides the measurement point for diode voltage monitoring. This multi-functionality eliminates the need for separate protection circuitry while maintaining comprehensive diode protection 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
The system provides reliable voltage regulation and protection for diodes, reducing the risk of failure and simplifying production by eliminating the need for direct epoxy placement and additional connections, while maintaining efficient spark generation.
Implementation Method 1
a first transformer (T1) including a first primary winding (L1) inductively coupled to a first secondary winding (L2); a second transformer (T2) including a second primary winding (L3) inductively coupled to a second secondary winding (L4)
Data Source
AI summary
A multi-charge ignition system including a spark plug control unit (13) adapted to control at least two coil stages so as to successively energise and de-energise said coil stage(s) to provide a current to a spark plug, said two stages comprising a first transformer (T1) including a first primary winding (L1) inductively coupled to a first secondary winding (L2); a second transformer (T2) including a second primary winding (L3) inductively coupled to a second secondary winding (L4); a first switch Q1 electrically connected between the low side of the first primary winding L1 and the low side/earth, a second switch Q2 having a connection to the low side of the second primary winding L3; and including a first diode D1 electrically connected between the low side of said first secondary winding L3 and ground, and a second diode D2 connected to a point between the low side of said second secondary winding L4 and ground and, including means to measure the voltage at a first connection point (203a) between the first switch and the low side of L1 and/or the voltage at a second connection (203b) point between the second switch and the low side of L3; and means to control the operation of the system dependent upon said measured voltages.