Fan Motor Stopping via Short-Circuit Loop and Segmented Power Paths
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Solution Overview
Problem
Conventional fan systems fail to effectively stop the motor when power is disconnected, leading to potential user danger and inefficiency due to inertia-driven rotation, and require high-capacity capacitors, increasing production costs.
Innovation Solution
A fan system design where a start-up device generates a distinct start-up signal on the power path, separate from the driving signal on the control path, allowing for a short-circuit loop to stop the motor, and using a start-up device with a start-up capacitor, resistor, and Zener diode to ensure efficient stopping without high-capacity storage capacitors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the storage capacitor CE releases power to both the driver 30 and the first capacitor C1 simultaneously, then the motor 40 can be stopped through the start-up signal S, but the driver 30 also generates driving signal P at the same time causing the selecting device 50 to select the driving signal instead of the start-up signal, preventing normal stopping function
Solution Approach 1:
The patent divides the power release path into two separate branches: one branch connects the storage capacitor CE to the driver 30 through the small signal power 20 for generating control signals, and another branch connects the storage capacitor CE to the first capacitor C1 directly for generating the start-up signal S. This segmentation ensures that the start-up signal and driving signal are generated independently without interference, allowing the selecting device to correctly identify and execute the start-up signal for motor stopping.
2Reliability
If the capacitance of the storage capacitor CE is increased to provide enough power to both power and control paths, then the motor can be reliably stopped, but the production costs are increased
Solution Approach 1:
The patent segments the power distribution into two independent paths from the storage capacitor CE, allowing each path to be optimized separately. The control path through the small signal power 20 supplies only the driver 30, while the direct path supplies the first capacitor C1 for start-up signal generation. This segmentation enables the use of smaller, lower-cost capacitors compared to a single high-capacity capacitor that would be required to supply both paths simultaneously.
Solution Approach 2:
The patent introduces the small signal power 20 as an intermediary component between the storage capacitor CE and the driver 30. This intermediary allows the control path to be electrically isolated from the direct power path, enabling the driver to receive sufficient power for generating control signals without requiring the storage capacitor to provide excessive total capacity. The intermediary structure reduces the overall capacitance requirement and associated costs.
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
The solution prevents motor failure during power disconnection, reduces production costs by eliminating the need for high-capacity capacitors, and ensures safe and efficient motor stopping.
Implementation Method 1
A fan system design where a start-up device generates a distinct start-up signal on the power path, separate from the driving signal on the control path, allowing for a short-circuit loop to stop the motor, and using a start-up device with a start-up capacitor, resistor, and Zener diode to ensure efficient stopping without high-capacity storage capacitors.
Implementation Method 2
The selecting device 50 outputs the start-up signal S to the motor 40 and forms a short-circuit loop in the motor 40, and thus an induction current is generated in a coil L of the motor 40 due to inertia after power disconnection so that a magnetic field in an inverse direction is generated to stop the inertia rotation of the motor 40.
Data Source
AI summary
A fan system and a stopping method for the fan system are provided. The fan system is electrically connected to a power supply and receives the power therefrom. The fan system includes an energy storage apparatus, a motor and a start-up device. The energy storage apparatus receives and stores the power. The motor is electrically connected to the energy storage apparatus and receives the power. The driver is coupled between the energy storage apparatus and the motor to form a control path and generates a driving signal to the motor according to received power. The start-up device is coupled between the energy storage apparatus and the motor to form a power path therewith. When no power is provided to the fan system, the energy storage apparatus releases the stored power and the start-up device generates a start-up signal to the motor in accordance with the released power so as to form a short-circuit loop in the motor to stop the motor.