Power Tool Bog-Down Control for Excessive Load Feedback
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-powered electric motor driven power tools lack the bog-down feedback mechanism, leading to potential damage from excessive loading, as they do not innately provide resistive forces like gas engine-powered tools, causing excessive current draw and battery depletion.
Innovation Solution
The power tool incorporates an electronic processor that detects load thresholds and controls a power switching network to simulate bog-down by reducing motor speed or oscillating between speeds, providing user feedback similar to gas engine-powered tools, and includes an eco-indicator for visual and auditory alerts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high-powered electric motor is used to increase power output, then productivity is improved, but the tool lacks bog-down feedback mechanism leading to excessive current draw and potential damage
Solution Approach 1:
The patent implements a feedback mechanism by monitoring motor current and comparing it to predetermined thresholds. When the current exceeds the threshold, the system activates an eco-indicator to alert the operator, providing feedback about excessive loading conditions similar to the natural bog-down feedback in gas engine tools.
Solution Approach 2:
The patent replaces the mechanical bog-down feedback mechanism of gas engine tools with an electrical monitoring system. Instead of relying on mechanical resistance and engine stalling, the system uses current sensors, microprocessors, and electronic indicators to detect and communicate excessive loading conditions.
2Productivity
If continuous operation at high power is maintained, then productivity is improved, but battery life is depleted due to excessive current draw
Solution Approach 1:
The system continuously monitors motor current and provides feedback through the eco-indicator when excessive current draw is detected. This allows the operator to adjust operation to prevent battery depletion while maintaining productivity during normal operating conditions.
Solution Approach 2:
The patent applies partial action by selectively activating the eco-indicator only when current exceeds the threshold, rather than continuously alerting the operator. This allows normal high-power operation to continue uninterrupted while providing warnings only when battery conservation is needed.
3Reliability
If bog-down feedback mechanism is added to simulate gas engine behavior, then reliability is improved through operator awareness, but device complexity increases due to additional sensors and control circuitry
Solution Approach 1:
The patent replaces complex mechanical bog-down mechanisms with a simpler electrical monitoring system. The system uses current sensors and a microprocessor to detect excessive loading and activates an eco-indicator, achieving reliable operator awareness with less mechanical complexity.
Solution Approach 2:
The patent introduces an intermediary eco-indicator that translates complex electrical current measurements into simple visual alerts for the operator. This intermediary component bridges the gap between the monitoring system and the operator, providing clear feedback without requiring complex control mechanisms.
4Reliability
If current monitoring and eco-indicator system is implemented, then protection from excessive loading is improved, but manufacturing cost increases due to additional components
Solution Approach 1:
The patent replaces expensive mechanical protection mechanisms with more cost-effective electrical monitoring components. The system uses affordable current sensors, a microprocessor, and an LED-based eco-indicator to provide reliable protection, reducing manufacturing costs compared to mechanical alternatives.
Solution Approach 2:
The patent creates a simplified electrical copy of the gas engine bog-down feedback mechanism. Instead of replicating the complex mechanical resistance and stalling behavior, the system uses electrical current monitoring to detect and alert about excessive loading, achieving the same protective function at lower cost.
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
Simulated bog-down system and method for power tools. One power tool according to an example embodiment includes a power source and a motor selectively coupled to the power source. The motor includes a rotor and stator windings. The power tool includes an actuator configured to generate a drive request signal and a power switching network configured to selectively couple the power source to the stator windings of the motor. The power tool includes an electronic processor coupled to the power source, the actuator, and the power switching network. The electronic processor is configured to detect a load on the power tool and compare the load to a threshold. The electronic processor is configured to determine that the load is greater than the threshold, and to control the power switching network to simulate bog-down in response to determining that the load is greater than the threshold.