Dual-Switch Power Tool Trigger for High-Current Spark Control
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Solution Overview
Problem
Power tools with high working currents face safety hazards due to spark-induced deformation or failure of high-current switch contacts, leading to inaccurate switch control and potential safety issues.
Innovation Solution
A power tool design featuring a current switch with copper sheet connections to prevent sparking and a signal switch controlled by a trigger mechanism, ensuring reliable operation and safety during high-current conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a high-current switch is used to carry large working current in power tools, then the power tool can operate at high power, but the switch contacts are prone to sparking which leads to deformation or failure
Solution Approach 1:
The patent divides the switching function into two separate switches: a first switch (current switch) that carries the high working current, and a second switch (control switch) that controls the first switch's on/off state. This segmentation allows the control switch to operate at low current while the current switch handles high current, resolving the contradiction between power capability and switch reliability.
Solution Approach 2:
The patent introduces a control circuit as an intermediary between the user's switching action and the high-current path. The control circuit detects the state of the second switch and uses this signal to control the first switch, thereby mediating the control function away from the high-current path and preventing sparking-related failures.
2Power
If a high-current switch is used to carry large working current, then high power operation is enabled, but the switch control accuracy deteriorates due to contact deformation or failure
Solution Approach 1:
By segmenting the switching function into a current switch and a control switch, the patent ensures that the control switch operates at low current where contact precision is maintained, while the current switch handles high current. This segmentation preserves switch control accuracy despite high power operation.
Solution Approach 2:
The control circuit implements feedback by detecting the state of the second switch and using this information to control the first switch. This feedback mechanism ensures accurate control of the high-current path without direct mechanical contact in the high-current switching path, maintaining control precision.
3Power
If a high-current switch is used in the main circuit, then large working current can be carried, but safety hazards increase due to sparks causing contact deformation or failure
Solution Approach 1:
The patent segments the switching system so that the control switch and its associated control circuit operate at low current, eliminating sparking hazards in the control path. The current switch handles high current but is controlled indirectly, reducing the frequency and intensity of sparking events and associated safety hazards.
Solution Approach 2:
The control circuit serves as an intermediary that eliminates direct human interaction with high-current switching operations. By detecting the control switch state and automatically controlling the current switch, the system mediates away the harmful sparking effects from the control path, improving safety.
Data Source
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AI summary
Disclosed is a power tool including: a tool accessory, a motor, a control module, a power supply, and an operating switch. The operating switch includes: a trigger mechanism; a current switch coupled to the trigger mechanism to be actuated by the trigger mechanism, for connecting and disconnecting the electrical connection between the power supply module and the motor; a signal switch coupled to the trigger mechanism to be actuated by the trigger mechanism, at least configured to output a control signal to the control module to control the start of the motor. The power tool of the present application makes the switch control unlikely to fail.