Hand-Held Power Tool Motor Load Detection via Magnetic Field Sensor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hand-held power tools face challenges in simplifying and improving load detection of electric motors, as current measurement is often required in the power line, which can be complex and less accurate.
Innovation Solution
Incorporating a magnetic field sensor to detect the magnetic field generated by the motor's current-carrying conductor, allowing for contactless and accurate current measurement and load detection, enabling differentiation between various operating states and optimizing motor control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current measurement is implemented in the power line for load detection, then load detection can be performed, but the device complexity and measurement accuracy are insufficient
Solution Approach 1:
The patent introduces a magnetic field sensor as an intermediary device to detect current indirectly through the magnetic field generated by the current-carrying conductor. This mediator approach eliminates the need for direct current measurement in the power line, simplifying the device complexity while improving measurement accuracy through non-contact detection.
Solution Approach 2:
The patent replaces the traditional electrical current measurement system with a magnetic field detection system. Instead of measuring current directly through electrical contacts in the power line, the system uses a magnetic field sensor to detect the magnetic field generated by the current, substituting an electrical measurement approach with a magnetic field-based approach.
2Ease of operation
If magnetic field sensor is used for contactless current measurement, then measurement accuracy and ease of operation are improved, but device complexity increases
Solution Approach 1:
The magnetic field sensor serves as an intermediary that enables contactless current measurement by detecting the magnetic field generated by the current-carrying conductor. This intermediary approach provides ease of operation through non-contact detection while the sensor and control system manage the added complexity in a controlled manner.
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
Enables precise load detection and control of hand-held power tools, improving energy efficiency by adapting motor speed based on detected load states without the need for direct current measurement in the electronics.
Implementation Method 1
a magnetic field sensor for detecting a magnetic field of the motor that is created by the driving of the tool holder
Implementation Method 2
the magnetic field sensor detects the magnetic field of the motor that is created by the driving of the tool holder. In particular, the magnetic field sensor measures a magnetic field generated by a current-carrying conductor of the motor
Data Source
AI summary
A hand-held power tool includes a tool holder, a motor for rotational and/or percussive driving of the tool holder, and a magnetic field sensor disposed in a vicinity of the motor, where a magnetic field of the motor that is created by driving the tool holder by the motor is detectable by the magnetic field sensor. The hand-held power tool further includes a control device where the control device determines a load state of the motor in dependence on a detected magnetic field of the motor and differentiates between an idle mode of the hand-held power tool and a load mode of the hand-held power tool based on the determined load state of the motor.