Normally-On Power Tool Control for Idle Power and Wear Reduction

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Solution Overview

Problem

Battery-powered power tools face inefficiencies and mechanical deterioration due to improper control, leading to unnecessary electricity consumption and safety hazards, especially in 'normally-on' tools that continue operating without continuous user activation.

Innovation Solution

A control system for power tools that includes an acquisition circuit to monitor parameters like current, voltage, and rotational speed, switching between working and standby modes to conserve energy and prevent unnecessary operation, featuring sensors, timing circuits, and load indicators to manage power usage and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the power tool operates in normally-on mode without continuous user activation, then operational convenience is improved, but unnecessary electricity consumption and mechanical deterioration occur

Engineering Contradiction:
Improveoperational convenienceVSAvoidelectricity consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The power tool implements dynamic operational modes (working mode and standby mode) that automatically adjust based on detected states. The control circuit switches between full power operation and reduced power consumption mode, allowing the tool to maintain convenience while adapting energy usage to actual operational needs.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The acquisition circuit continuously monitors parameters such as current, voltage, and rotational speed, providing feedback to the control circuit. This feedback mechanism enables the system to detect when the tool is actually performing work versus when it is idle, triggering appropriate mode transitions to optimize energy consumption.

Inventive Principle:
Principle #23Feedback

2Ease of operation

If the power tool operates continuously without control, then operational convenience is improved, but mechanical deterioration and safety problems worsen

Engineering Contradiction:
Improveoperational convenienceVSAvoidmechanical durability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The acquisition circuit monitors operational parameters and provides feedback to the control circuit, enabling detection of abnormal states such as excessive current, voltage fluctuations, or prolonged idle operation. This feedback allows the system to intervene and prevent mechanical damage before it occurs.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system automatically monitors its own operational state and takes corrective action without external intervention. The acquisition circuit and control circuit work together to self-diagnose abnormal conditions and switch modes or shut down the power device to prevent mechanical deterioration.

Inventive Principle:
Principle #25Self-service

3Productivity

If the power tool operates in working mode continuously, then productivity is maintained, but energy consumption and mechanical wear increase

Engineering Contradiction:
Improveoperational outputVSAvoidenergy waste
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The system dynamically transitions between working mode and standby mode based on actual operational needs. When the acquisition circuit detects that the tool is not performing useful work (e.g., idle period after trigger release), the control circuit switches to standby mode, eliminating energy waste while maintaining productivity during actual work periods.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control system implements periodic monitoring of operational parameters and periodic switching between modes. The acquisition circuit continuously or intermittently checks system state, and the control circuit periodically transitions modes based on detected conditions, ensuring energy is consumed only when necessary for productive work.

Inventive Principle:
Principle #19Periodic action

4Use of energy by moving object

If the power tool implements automatic mode switching, then energy consumption is reduced, but device complexity increases

Engineering Contradiction:
Improveelectricity consumptionVSAvoidcontrol system complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The acquisition circuit serves multiple functions: monitoring current, voltage, rotational speed, and detecting various abnormal states. The control circuit handles both normal mode transitions and abnormal state responses. This multi-functionality reduces the need for separate dedicated components for each function, thereby limiting the increase in overall device complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4052794A1Control system for normally-on power tool
Publication Date: 2022.09.07 TECHTRONIC CORDLESS GP
  • EP4052794A1 patent drawingFigure 1
  • EP4052794A1 patent drawingFigure 2~4A
  • EP4052794A1 patent drawingFigure 4B~4E

AI summary

Disclosed in the present invention is a control system for a normally-on power tool. The power tool comprises a tool head and a power device for providing the tool head with power, and the control system comprises an acquisition circuit and a control circuit. The acquisition circuit is in electrical communication with the power device and used to acquire at least one parameter associated with the power device, and the control circuit is configured to put the power device in a working mode with a first output power or a standby mode with a second output power according to the at least one parameter. The control system according to one or more embodiments of the present invention can save energy consumption, reduce mechanical wear, increase the service life of the power tool, and enhance operation convenience and safety.