Abstract: A single-phase motor with positive and negative turn detection, including a rotor assembly, a master hall element, a secondary hall element, and a control assembly. The rotor assembly includes a magnetic ring and a permanent magnet. The magnetic ring includes magnetic strips that are connected end to end. The permanent magnet includes a plurality of magnetic ends. The master hall element is located at a lead position of the permanent magnet. A jitter point is defined between one magnetic end corresponding to the master hall element and one magnetic end adjacent to the master hall element in the clockwise direction. The secondary hall element is located on a side facing the counter clockwise direction of the master hall element. A first angle between the secondary hall element and the master hall element is greater than a second angle between the jitter point and the lead position.

Abstract: A fan frame includes a central base, a frame wall, and a plurality of static blades radially extending from the central base to the frame wall, each static blade is connected to the central base at a first end and connected to the frame wall at a second end, the central base is provided with a first wire groove, the frame wall is provided with a second wire groove, the first wire groove and the second wire groove are configured for accommodating wires, and the second wire groove has a shape same as the second end of the static blade connected to the frame wall for gathering the wires to shape similar to the static blade. A fan assembly including the fan frame is also disclosed.

Abstract: An indoor sound-modulating device is provided. The indoor sound-modulating device includes a low-frequency noise detector, an automatic actuator and an audio signal generator. The low-frequency noise detector detects low-frequency noise and generates a first modulating signal in response to the detected low-frequency noise. The automatic actuator issues a second modulating signal in response to a predetermined state. The audio signal generator generates a low-frequency audio signal for eliminating the low-frequency noise in response to the first modulating signal and generates a high-frequency repellent audio signal in response to the second modulating signal. The low-frequency audio signal has a frequency ranging from 20 Hz to 350 Hz, while the high-frequency repellent audio signal has a frequency not less than 8000 Hz.

Abstract: An indoor sound-modulating device is provided. The indoor sound-modulating device includes a low-frequency noise detector, an automatic actuator and an audio signal generator. The low-frequency noise detector detects low-frequency noise and generates a first modulating signal in response to the detected low-frequency noise. The automatic actuator issues a second modulating signal in response to a predetermined state. The audio signal generator generates a low-frequency audio signal for eliminating the low-frequency noise in response to the first modulating signal and generates a high-frequency repellent audio signal in response to the second modulating signal. The low-frequency audio signal has a frequency ranging from 20 Hz to 350 Hz, while the high-frequency repellent audio signal has a frequency not less than 8000 Hz.

Abstract: An elimination system for diverting dental instrument noise includes an audio player, a sound sensor, and a controller. The audio player is used for broadcasting an audio content. The sound sensor may sense noise from a dental instrument, thereby outputting a sensing signal. The controller is electrically connected with the audio player and the sound sensor. According to the sensing signal from the sound sensor, the controller controls the audio content that is broadcasted by the audio player.

Abstract: A torque limiting device for a wheeled vehicle includes a fixed boss, a plurality of rolling balls, a roller retainer, a roller seat, several disk springs, and a driven housing. Thus, when the wheeled vehicle is suddenly braked under the emergency condition or when the rear tires are subjected to a larger resistance and excessive torque, the driven shaft disengages from the fixed boss, and the rotation of fixed boss cannot drive and rotate the driven shaft, such that the driven shaft stops rotating temporarily, thereby preventing the transmission parts of the CVT and reducing speed system of the wheeled vehicle from being broken or worn out by the excessive torque.