Plasma Ignition Noise Reduction Circuit Topology
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Plasma ignition systems for internal combustion engines generate significant electromagnetic noise due to high-frequency current flows, which can lead to misfires and interfere with electronic control systems, and existing noise reduction methods, such as shielding, are impractical in crowded engine compartments and can introduce new noise sources.
Innovation Solution
A plasma ignition system incorporating an electromagnetic noise reduction circuit with a first and second rectifier and a noise reducing capacitor, positioned between the discharging and plasma generating power circuits, to block current flows and reduce electromagnetic noise, while being integrated within the plug cap to minimize stray capacitance and noise leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a plasma generating power circuit with high energy capacitor is used to generate high temperature plasma gas, then ignition reliability is improved, but electromagnetic noise is generated causing misfires
Solution Approach 1:
The power supply system is segmented into two independent circuits: a discharging power circuit for generating the secondary voltage and a plasma generating power circuit for storing and discharging high energy. This segmentation allows each circuit to be optimized independently, with the plasma generating circuit equipped with noise reduction components while the discharging circuit maintains its ignition function.
Solution Approach 2:
A noise reduction circuit acting as an intermediary is introduced between the plasma generating capacitor and ground. This circuit includes a first rectifier connected in series to block high-frequency noise current, and a second rectifier with a parallel capacitor to provide a low-impedance path for noise current, effectively filtering electromagnetic noise before it can cause misfires.
2Object-generated harmful factors
If shielding is used to reduce electromagnetic noise, then noise radiation is reduced, but device complexity increases and space is consumed
Solution Approach 1:
The mechanical shielding system is replaced with an electrical noise reduction circuit. Instead of using physical shields, ferrite beads, or grounded enclosures to block electromagnetic radiation, the invention uses electronic components (rectifiers and capacitors) to actively filter and redirect noise current, achieving noise reduction without adding mechanical complexity or consuming valuable engine compartment space.
3Object-generated harmful factors
If a noise reduction circuit with rectifiers and capacitor is added, then electromagnetic noise is reduced, but circuit complexity increases
Solution Approach 1:
The noise reduction circuit components serve multiple functions: the first rectifier blocks high-frequency noise current while also protecting the capacitor from reverse polarity; the second rectifier with parallel capacitor provides noise filtering while also serving as a discharge path for the capacitor. This multi-functionality reduces the need for additional components, minimizing circuit complexity while maintaining effective noise reduction.
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 electromagnetic noise radiation, preventing misfires and ensuring reliable engine operation by bypassing high-frequency noise without attenuating discharge voltage, and is practical for use in multi-cylinder engines with minimal potential differences due to fixed shield capacitance.
Implementation Method 1
an ignition coil (33) receiving a primary voltage and generating a secondary voltage higher than the first voltage based on the first voltage
Implementation Method 2
a plasma generating capacitor or capacitors (43), which is provided to store electric energy by being charged by the battery (41) through the resistor (42)
Implementation Method 3
a first rectifier (21), which is disposed in the discharging wire to block a current flowing in the plasma generating wire from flowing into the discharging wire
Data Source
AI summary
A plasma ignition system has an electromagnetic noise reduction circuit in addition to a discharge power circuit, a plasma generating power circuit, a plasma ignition plug, a discharging wire and a plasma generating wire. The noise reduction circuit includes a first rectifier connected to the discharging wire, a second rectifier connected to the plasma generating wire, and a noise reducing capacitor connected in parallel to the second rectifier. The noise reduction circuit is disposed close to the ignition plug so that the noise reducing capacitor bypasses only high frequency noise currents generated when the ignition plug discharges.