Ignition Connection Device Noise Suppression via Inductor Extraction
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Solution Overview
Problem
In ignition systems, the large size of diodes required to suppress noise near the ignition plug poses challenges due to heat generation and size constraints, especially in compact combustion apparatuses, making it difficult to effectively manage stray capacitance-induced noise without increasing the apparatus size.
Innovation Solution
A connection device with an inductor placed between the diode and the ignition plug in the first power supply side line, and a resistor in the second power supply side line, to attenuate high-frequency currents from stray capacitance, reducing noise without relying on diodes for noise suppression and allowing for a more compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a diode is disposed close to the center electrode to minimize stray capacitance, then noise suppression is improved, but the apparatus size increases and heat management becomes difficult
Solution Approach 1:
The harmful function of the first power supply side diode (noise generation due to stray capacitance) is extracted and eliminated by removing the diode entirely. Instead, an inductor is introduced to achieve noise suppression through a different mechanism that does not require the diode to be disposed close to the center electrode, thus avoiding the size and heat management problems.
Solution Approach 2:
The invention changes the approach from using a diode (which has inherent stray capacitance) to using an inductor (which has inductance property). This parameter change in the circuit element type allows for noise suppression without the need to minimize wiring length, thereby avoiding the constraint of disposing components close to the center electrode and reducing apparatus size.
2Object-affected harmful factors
If a diode is disposed close to the center electrode to minimize stray capacitance, then noise suppression is improved, but the diode may be broken due to heat generated from combustion apparatus operation
Solution Approach 1:
The unreliable component (first power supply side diode) is extracted and removed from the system. The inductor is introduced as a replacement component that does not suffer from the same heat-related reliability issues, thereby improving overall system reliability while maintaining noise suppression functionality.
3Object-affected harmful factors
If the diameter of the plug hole is increased to accommodate a large diode, then noise suppression is improved, but the apparatus size increases
Solution Approach 1:
The requirement for a large diode (which necessitates increased plug hole diameter) is extracted and eliminated. The inductor-based noise suppression solution does not require large component sizes or increased plug hole diameter, thus maintaining compact apparatus dimensions while achieving the same noise suppression effect.
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 effectively suppresses noise by reducing stray capacitance and high-frequency currents, allowing for reliable operation without the need for large diodes, thus maintaining compactness and preventing diode breakage due to heat, while ensuring efficient power supply to the ignition plug.
Implementation Method 1
an inductor disposed between the first diode and the ignition plug... a high frequency current that flows from a stray capacitance of a portion of the first power supply line located upstream of the inductor to the ignition plug immediately after generation of a spark discharge is attenuated by the inductor
Implementation Method 2
a first power supply side line which establishes connection between the ignition plug and the first power supply... includes a first diode which prevents a current inflow from the second power supply into the first power supply
Implementation Method 3
a resistor provided between the ignition plug and the second power supply... to thereby minimize the length of the wiring between the ignition plug and the resistor... whereby noise can be suppressed
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A connection device (60) for connecting a first power supply (41) and a second power supply (31) to an ignition plug (1) has a first power supply side line (71) which establishes electrical connection between the ignition plug (1) and the first power supply (41) and which is electrically connected to the second power supply (31), and a second power supply side line (61) which establishes electrical connection between the ignition plug (1) and the second power supply (31). The first power supply side line (71) includes a first diode (72) which prevents a current inflow from the second power supply (31) into the first power supply (41) or a current inflow from the first power supply (41) into the second power supply (31), and an inductor (73) disposed between the first diode (72) and the ignition plug (1). The inductor (73) is disposed around the second power supply side line (61) while being separated from the second power supply side line (61). Thus, noise can be suppressed.