Ignition Coil With Spaced Windings For High-Frequency AC
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Solution Overview
Problem
Conventional ignition coils struggle to provide an extended-duration high-voltage spark necessary for efficient combustion in direct injection engines, particularly in natural gas engines, due to degradation issues and limited energy output in compact designs, and they often require dielectric materials that can degrade under high voltages.
Innovation Solution
The design features a ferrite core ignition coil with a secondary winding having 7000 turns and a primary winding spaced longitudinally away from the secondary winding, utilizing a MOSFET controller to oscillate alternating current at a high frequency, eliminating the need for dielectric materials and ensuring consistent energy delivery across the spark plug electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the ignition coil is made compact to fit limited engine space, then the space requirement is reduced, but the energy output and spark duration are insufficient
Solution Approach 1:
The patent changes the electrical parameters by using high-frequency alternating current (20-100 kHz) instead of conventional low-frequency DC ignition. This parameter change allows a compact coil design to generate sufficient spark energy through high-frequency oscillation, resolving the contradiction between small size and adequate power output
Solution Approach 2:
The patent employs periodic alternating current oscillation at high frequencies to generate the ignition spark. This periodic action allows the compact ignition coil to deliver energy in repeated cycles, achieving sufficient total energy output and extended spark duration despite the reduced coil size
2Reliability
If dielectric materials are used between primary and secondary windings to prevent electrical breakdown, then insulation is provided, but the dielectric materials degrade under high voltage over time
Solution Approach 1:
The patent extracts and eliminates the dielectric material from the ignition coil design. By using high-frequency alternating current, the patent achieves electrical insulation through the inherent properties of the winding arrangement and air gap, removing the degrading dielectric material entirely and thus resolving the contradiction between providing insulation and maintaining long-term reliability
Solution Approach 2:
The patent uses air as an intermediary medium between the primary and secondary windings instead of solid dielectric materials. The high-frequency alternating current creates an electrical field that is contained by the air gap and winding geometry, providing insulation without the degradation issues of solid dielectrics
3Productivity
If single-direction DC spark is used to ignite fuel, then ignition is achieved, but electrode degradation occurs over time
Solution Approach 1:
The patent uses periodic alternating current to generate bidirectional sparks that alternate between the two electrodes. This periodic reversal of current direction prevents localized electrode degradation by distributing wear evenly across both electrodes, thereby extending spark plug life while maintaining effective ignition
Solution Approach 2:
The patent inverts the conventional unidirectional DC spark approach by using bidirectional alternating current. Instead of current flowing in one direction from positive to negative electrode, the current alternates direction, causing sparks to jump both ways and preventing asymmetric electrode erosion
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 achieves a 50,000-volt spark of extended duration, reducing electrode degradation and enhancing fuel efficiency, while avoiding dielectric material degradation and accommodating the compact space requirements of modern engines.
Implementation Method 1
a primary winding wrapped around the sleeve... The primary winding is in spaced longitudinal relationship from the low voltage end of the secondary winding and located away from the high-voltage end of the secondary winding
Data Source
AI summary
An ignition coil has a core with a longitudinal axis, a secondary winding extending around the core, a sleeve extending around the core, a primary winding wrapped around the sleeve, and a controller connected to the primary winding so as to oscillate alternating current to said primary winding. The secondary winding has a high-voltage end and a low-voltage end. The primary winding is in spaced longitudinal relationship from the secondary winding. Specifically, the primary winding is located longitudinally away from the high-voltage end of the secondary winding. A bobbin is positioned over and around the core. The secondary winding is wrapped around at least a portion of the bobbin.