Ionization Detector Ignition Coil Inductance Shorting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-energy ignition coils in internal combustion engines attenuate ionization signals due to increased inductance, preventing the engine control module from detecting combustion quality, such as knock events, as existing ionization detectors are filtered by the ignition coil's parasitic low-pass effect.
Innovation Solution
An ionization detector apparatus that includes an ignition coil with a primary and secondary winding, a bias voltage source, and an inductance control switch, which shorts the primary winding's inductance to reduce secondary impedance, allowing frequencies from DC to knock frequencies to be passed, thereby reducing signal attenuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If higher inductance ignition coils are used to provide higher energy, then the ignition energy is improved, but the ionization signal is attenuated due to the parasitic low-pass filter effect
Solution Approach 1:
The patent applies dynamics by making the ignition coil's inductance characteristic changeable through a switchable capacitor. The capacitor can be connected in parallel with the primary winding to reduce the effective inductance during ionization detection, thereby reducing signal attenuation while maintaining high inductance for high-energy ignition when the capacitor is disconnected.
Solution Approach 2:
The patent changes the electrical parameter (inductance) of the ignition coil by introducing a switchable capacitor. This allows the system to transition between high-inductance mode for high-energy ignition and low-inductance mode for accurate ionization signal detection, effectively resolving the contradiction between ignition energy and measurement precision.
2Measurement precision
If the inductance of the ignition coil is reduced to pass knock frequencies, then the ionization signal transmission is improved, but the ignition energy is reduced
Solution Approach 1:
The system dynamically adjusts the inductance of the ignition coil based on the operational phase. During the ionization detection phase, the capacitor is connected to reduce inductance and pass knock frequencies. During the ignition phase, the capacitor is disconnected to maintain high inductance for high ignition power.
Solution Approach 2:
The patent employs periodic switching of the capacitor connection to alternate between detection mode (low inductance) and ignition mode (high inductance). This periodic action allows the system to optimize for different functions at different times, achieving both accurate knock detection and high ignition power.
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 solution effectively reduces the filtering effects of the ignition coil on the ionization signal, enabling the engine control module to detect combustion quality and knock events more accurately by ensuring that frequencies from DC through the knock frequency are passed, improving combustion optimization.
Implementation Method 1
an ignition coil, including a primary winding and a secondary winding... supplies electric voltage across an electrical gap by way of the secondary winding
Data Source
AI summary
An ionization detector that reduces the filtering effects of the ignition coil inductances by shorting an inductance of a primary winding of the ignition coil. The ionization detector includes a bias voltage source and an inductance control switch. The bias voltage source supplies electric voltage across an electric gap of a spark plug for detecting ionization within the combustion chamber. The inductance control switch is electrically parallel with a primary winding of an ignition coil and is operable to short an inductance of the primary winding.