Battery Pack Signal Detection for Tool Coupling and Switch States

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Solution Overview

Problem

Existing battery packs cannot detect when an electric power tool is coupled without the trigger switch being turned ON, leading to inefficiencies in preparing for discharge or charge, and increasing the number of terminals to solve this issue results in size increases of both the battery pack and the power tool.

Innovation Solution

A battery pack with a communication terminal that receives and distinguishes between signals indicating uncoupling, ON, and OFF states using different potentials, allowing detection without increasing the number of terminals, and includes a potential generator to differentiate these signals and a shut-down outputter to indicate a shut-down state.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If the number of terminals is increased to allow output of a greater number of signals from the electric power tool body to the battery pack, then the battery pack can detect more signals (such as switch ON/OFF states and coupling status), but the size of the circuit board included in the battery pack increases, leading to size increase of the battery pack

Engineering Contradiction:
Improvesignal detection capabilityVSAvoidbattery pack size
Core Design Contradiction:
Loss of informationVSVolume of moving object

Solution Approach 1:

The communication terminal is designed to handle multiple signal types (uncoupling signal, ON signal, OFF signal) through a single interface. The terminal universally processes different potential levels to distinguish between various operational states, eliminating the need for separate terminals for each signal type while maintaining full detection capability

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

Solution Approach 2:

The system uses different potential levels (first potential for uncoupling, second potential for ON, third potential for OFF) to encode multiple signal meanings within a single terminal. By changing the electrical parameter (potential) rather than adding physical terminals, the system achieves multi-signal detection without increasing battery pack size

Inventive Principle:
Principle #35Parameter changes

2Loss of information

If the number of terminals is increased to allow output of a greater number of signals from the electric power tool body to the battery pack, then the battery pack can detect more signals, but the size of the circuit board included in the electric power tool body increases, leading to size increase of the electric power tool body

Engineering Contradiction:
Improvesignal detection capabilityVSAvoidelectric power tool body size
Core Design Contradiction:
Loss of informationVSVolume of moving object

Solution Approach 1:

The device-side communication terminal is designed as a universal interface that outputs multiple signal types through a single terminal. This multi-functional terminal reduces the number of connection points needed on the power tool body, thereby reducing circuit board size and overall tool dimensions

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

Solution Approach 2:

Multiple signal output functions (uncoupling indication, switch ON indication, switch OFF indication) are merged into a single communication terminal interface. This consolidation reduces the number of separate terminals and associated circuitry on the power tool body, leading to a more compact design

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If the battery pack is configured to recognize coupling of the electric power tool body upon coupling (before trigger switch is turned ON), then the battery pack can prepare for subsequent discharge or charge, but this requires additional signal detection capability that would normally require more terminals

Engineering Contradiction:
Improvedischarge preparation timeVSAvoidterminal configuration
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The battery pack performs preliminary detection of coupling status through the communication terminal before the trigger switch is activated. By detecting the uncoupling signal potential level upon connection, the battery pack can prepare its discharge circuitry in advance, ensuring immediate readiness when the user activates the tool, thus reducing overall system startup time

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3650177B1Battery pack and battery system
Publication Date: 2023.11.15 MAKITA CORP
  • EP3650177B1 patent drawingFigure 1
  • EP3650177B1 patent drawingFigure 2
  • EP3650177B1 patent drawingFigure 3

AI summary

A battery pack (100) in one aspect of the present disclosure includes a communication terminal (14) and a detector (310), and supplies electric power to an external device (600). The communication terminal receives a first signal, a second signal, and a third signal. The first signal has a first potential, the second signal has a second potential, and the third signal has a third potential. The first potential, the second potential, and the third potential are different from one another. The detector determines a potential at the communication terminal, to thereby detect the first signal, the second signal, or the third signal in accordance with the determined potential.