Power Tool Diagnostic Mode Switching via Voltage Signal Uniformity
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Solution Overview
Problem
Power tools with internal combustion engines and generators produce non-uniform voltage signals due to crankshaft rotation, making it difficult to diagnose the tool without separate switches or communication lines, especially when there is no battery or energy supply device.
Innovation Solution
A diagnostic device supplies a uniform voltage signal that automatically switches the electronic control unit into diagnostic mode, allowing for diagnosis without additional switches or signal transmission, using the generator's non-uniform voltage signal characteristics to determine the mode, and enabling data transfer through a diagnostic line.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the generator supplies a non-uniform voltage signal as energy supply, then the power tool can operate with its own energy supply, but the electronic control unit cannot automatically distinguish diagnostic mode from operating mode
Solution Approach 1:
The diagnostic device changes the voltage signal parameter from non-uniform (operating mode) to uniform (diagnostic mode). The electronic control unit detects this parameter change and automatically switches modes without requiring separate switches or communication lines, thus resolving the contradiction between ease of operation and device complexity
2Reliability
If a separate communication line is used for diagnostic mode switching, then mode switching is reliable, but the device configuration becomes more complex
Solution Approach 1:
The voltage signal line serves dual functions: it supplies energy to the electronic control unit during normal operation and transmits mode switching information during diagnostic mode. By making the energy supply line multi-functional, the patent eliminates the need for separate communication lines while maintaining reliable mode switching, thus resolving the contradiction between reliability and device complexity
3Adaptability or versatility
If an additional energy source like a battery is provided for the diagnostic device, then diagnostic operations can be performed independently, but the overall system complexity increases
Solution Approach 1:
The power tool's own generator is used to supply energy to the electronic control unit during diagnostic operations. The diagnostic device draws power from the generator through the existing voltage signal line, eliminating the need for separate batteries or external power sources. This self-service approach maintains diagnostic independence while avoiding additional energy supply devices, thus resolving the contradiction between adaptability and device complexity
Data Source
AI summary
In a method for operating a power tool with a diagnostic device, wherein the power tool has an internal combustion engine, a generator as an energy supply, and an electronic control unit, wherein a diagnostic device is connectable to the electronic control unit, and wherein the electronic control unit has an operating mode and a diagnostic mode, a non-uniform voltage signal is supplied by the generator as an energy supply and a uniform voltage signal is supplied by the diagnostic device as an energy supply. The electronic control unit evaluates the voltage signal that is being supplied as an energy supply and switches to diagnostic mode when the voltage signal is the uniform voltage signal supplied by the diagnostic device.