Rechargeable Electric Tool Motor-Lock Detection via Battery Voltage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electric tools struggle to reliably detect motor-lock conditions without additional sensors or circuits, particularly when battery voltage changes slowly, leading to potential motor damage due to thermal issues.
Innovation Solution
An electric tool design that measures and stores a reference voltage during motor-lock conditions, using this value to control motor operation by comparing it with real-time battery voltage, allowing for detection and prevention of motor-lock without additional sensors, and optionally adjusting the reference voltage based on temperature and battery level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional sensors or circuits are added to detect motor-lock, then detection reliability is improved, but device complexity increases
Solution Approach 1:
The battery voltage measurement function is made multi-functional: it serves both the existing overdischarge protection function and the new motor-lock detection function. By storing a reference voltage value representing motor-lock conditions in memory and comparing real-time voltage against this reference, the system achieves reliable motor-lock detection without adding dedicated sensors or circuits.
Solution Approach 2:
The system uses its own existing battery voltage measurement capability to detect motor-lock conditions, rather than relying on external sensors. The control unit leverages the voltage measurement already performed for overdischarge protection to simultaneously detect motor-lock by comparing voltage against the stored reference value.
2Device complexity
If overdischarge protection voltage threshold is used for motor-lock detection, then circuit simplicity is maintained, but detection precision deteriorates when battery voltage changes slowly
Solution Approach 1:
Instead of using a fixed overdischarge protection voltage threshold, the system dynamically adapts the detection threshold by storing a reference voltage value that specifically represents motor-lock conditions. This reference voltage is measured and stored during manufacturing or initial operation, and then used as the comparison基准 for detecting motor-lock, thereby improving detection precision while maintaining circuit simplicity.
3Device complexity
If motor-lock detection is implemented without additional sensors, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The battery voltage measurement function is made multi-functional: it serves both the existing overdischarge protection function and the new motor-lock detection function. By storing a reference voltage value representing motor-lock conditions in memory and comparing real-time voltage against this reference, the system achieves reliable motor-lock detection without adding dedicated sensors or circuits.
Solution Approach 2:
Instead of using a fixed overdischarge protection voltage threshold, the system dynamically adapts the detection threshold by storing a reference voltage value that specifically represents motor-lock conditions. This reference voltage is measured and stored during manufacturing or initial operation, and then used as the comparison基准 for detecting motor-lock, thereby improving detection precision while maintaining circuit simplicity.
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
Effectively detects motor-lock conditions in both rapid and slow voltage changes, preventing motor damage by stopping or decelerating the motor when the battery voltage remains below the reference threshold for a predetermined period, thus enhancing motor protection without additional sensor requirements.
Implementation Method 1
a voltage measurement section configured to measure a battery voltage
Implementation Method 2
an electric tool powered by a secondary battery
Implementation Method 3
a motor, a decelerator, and an output section configured to be transmitted thereto a rotation of the motor
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
Providing an electric tool that can reliably detect the occurrence of the motor-lock and can prevent the damage of the motor without adding a sensor and/or a circuit. The electric tool is powered by a secondary battery as a power source, and includes: an output section configured to be transmitted thereto a rotation of a motor 11 directly or through a decelerator; a voltage measurement section 31 that measures a battery voltage; a storage means 32 that stores, as a reference voltage, a voltage value of the battery voltage measured preliminarily when a motor-lock is occurring; and a control means 30 that controls a driving of the motor. The control means 30 is configured to decide that the motor 11 is being locked and then stop or decelerate the motor 11 upon detecting that the battery voltage measured through the voltage measurement section 31 is maintained lower than or equal to the reference voltage stored in the storage means 32 for a predetermined period of time during the driving of the motor.