Ignition Device Stop Switch Contact Cleaning via High Current Pulse
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Solution Overview
Problem
Existing methods for detecting the switching state of a stop switch in ignition devices for internal combustion engines are prone to residual errors due to incomplete cleaning of switch contacts, leading to unreliable actuation determination.
Innovation Solution
Generating a voltage signal with negative and positive half waves during discharge to synchronize sampling, ensuring a high current flow through the stop switch for reliable contact cleaning and accurate state detection, using a second power storage device charged before the ignition pulse to support this high current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If voltage pulses are applied to clean stop switch contacts, then contact cleaning is improved, but measurement precision deteriorates due to residual errors in detecting closed state
Solution Approach 1:
The patent applies a preliminary cleaning action by sending a high-current pulse through the stop switch contacts before the actual switching state detection. This pre-cleaning removes oxidations and impurities from the contacts, ensuring that subsequent voltage level measurements accurately reflect the true switching state without residual contamination causing measurement errors.
Solution Approach 2:
The patent maintains continuous monitoring of the stop switch voltage level throughout the ignition cycle, continuously comparing the measured voltage against threshold values to determine switching state. This continuous action ensures that any transient conditions or residual effects are immediately detected and corrected, maintaining measurement precision throughout operation.
2Ease of manufacture
If high current flow is generated through stop switch, then contact cleaning is improved, but device complexity increases due to additional power storage device
Solution Approach 1:
The patent makes the second power storage device serve multiple functions: it stores energy for generating high-current cleaning pulses through the stop switch, and simultaneously serves as the power source for the ignition system. By combining these functions into a single component, the patent avoids adding excessive complexity while still achieving effective contact cleaning.
Solution Approach 2:
The patent merges the cleaning function and ignition power supply function into a single power storage device. The same capacitor that powers the ignition spark also provides the energy for cleaning the stop switch contacts, eliminating the need for separate power sources and reducing overall system complexity.
3Reliability
If multiple voltage half waves are used for sampling, then reliability is improved, but loss of time increases due to extended sampling period
Solution Approach 1:
The patent uses periodic voltage half waves from the ignition cycle to synchronize sampling of the stop switch voltage level. By aligning sampling with the natural periodic voltage oscillations, the system achieves reliable measurements at optimal moments without requiring continuous or extended sampling periods, thus maintaining time efficiency.
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 approach allows for reliable detection of the stop switch's closed state without residual errors, ensuring clean contacts and accurate switching state determination, independent of contact material or construction.
Implementation Method 1
a voltage signal with negative and positive voltage half waves is generated advantageously during the discharge of the (first) power storage device
Implementation Method 2
Such a current flow with a relatively high current value reliably leads to a cleaning of the switch contacts of the stop switch and particularly to a reliable burning off of oxidations or other impurities
Implementation Method 3
The charging of said power storage device again expediently in the form of a capacitor occurs particularly in time before the stop sampling
Data Source
AI summary
The detection of the switching state of a stop switch at a switch terminal of an ignition device for an internal combustion engine is provided, in which an ignition pulse for controlling an electronic ignition switch is generated and a first power storage device is discharged via an ignition coil and during this discharge a voltage signal having negative and positive voltage half waves is generated, which is used for synchronizing a sampling, representing the switch state of the stop switch, particularly its closed position, of a voltage value at the switch terminal.