A rotation locking system of a motor of a fan is provided. A closed-loop control circuit outputs an initial duty cycle signal according to a current rotational speed and a target rotational speed. A driver circuit outputs a driving signal to the motor to drive the motor to rotate according to the initial duty cycle signal. A lookup table arithmetic circuit looks up, from a lookup table, two reference duty cycles correspond to two reference rotational speeds that are respectively equal to the current rotational speed and the target rotational speed. The lookup table arithmetic circuit calculates a difference between the two reference duty cycles. A speed feedback control circuit compensates the initial duty cycle signal according to the difference to output a final duty cycle signal to the driver circuit. The driver circuit drives the motor to rotate according to the final duty cycle signal.

The present disclosure relates to a portable air purifier and the fan module provided therin. In the disclosed invention, the portable air purifier includes a fan module that is disposed between a discharge surface and a filter, and suctions air having passed through the filter, in an axial direction, and discharges the air in a direction between the axial direction and a radial direction.

A vacuum pump and a stator column wherein partition walls from an outer peripheral surface of the stator column toward an inner periphery of a rotor blade are provided at two spots, and a groove-shaped channel in a circumferential direction is provided. A sectional area of the channel changes in the circumferential direction. As a result, the pressure difference between a front and a rear of the partition wall on a downstream side is made uniform regardless of a location, and a flowrate of the gas passing through a gap between the partition wall on the downstream side and the inner peripheral surface of the rotor blade is made uniform regardless of the location. The change in the sectional area is achieved either by changing a depth of the groove-shaped channel or by changing an interval between the partition walls at the two spots.

A ceiling fan assembly having a motor with a rotor and a stator, at least one blade operably coupled to the stator, a motor shaft extending from the stator and having an internal wire passage and a wire opening in a side of the motor shaft, with the wire opening providing access to the internal wire passage, a control mounting plate having a motor shaft opening through which the motor shaft extends and an electronic control unit carried by a side of the control mounting plate.

A ceiling fan assembly having a motor with a rotor and a stator, at least one blade operably coupled to the stator, a motor shaft extending from the stator and having an internal wire passage and a wire opening in a side of the motor shaft, with the wire opening providing access to the internal wire passage, a control mounting plate having a motor shaft opening through which the motor shaft extends and an electronic control unit carried by a side of the control mounting plate.

A fan module including a body and a plurality of blades is provided. The body has a rotating axis and the body is telescopic along the rotating axis to have an elongated state and a shortened state. The blades are respectively disposed on the body and rotate along with the body along the rotating axis. At least a portion of each blade is flexible and a bending state of each blade is changed along with the elongated state or the shortened state of the body. An axial size of each blade along the rotating axis when the body is in the elongated state is greater than the axial size of each blade along the rotating axis when the body is in the shortened state.

A control system is provided to optimize a compressor that has a variable guide vane position and a variable speed set point. One or more controllers receive a process set point for a main process variable for a first performance control application and a deviation set point for a surge deviation level for a second performance control application. The first performance control application operates a first independent primary control loop to control the main process variable at the process set point by manipulating the variable guide vane position. The second performance control application operates a second independent primary control loop to control a surge deviation level at the deviation set point by manipulating the variable speed set point. The second performance control application also executes a limit control loop to limit the main process variable at a limit set point by manipulating the variable speed set point.

A two-speed motor is mounted in a housing with an end cap. The end cap has a tubular structure defining an interior space, including an open first end connectable to the motor casing. The second end includes at least one planar surface and at least one air grate configured to permit airflow into and/or out of the interior space. A dual speed pump controller includes a motor controller for operating the dual speed motor. The controller includes an operating speed circuit for operating the motor in one of a first speed or a second speed, the first speed being greater than the second speed; an event circuit for operating the motor at the first speed before a predetermined event and operating the pump at the second speed after the predetermined event.

A compressor is provided. The compressor according to the present disclosure includes: one or more impellers suctioning and compressing refrigerant; a motor rotating the impeller; a rotation shaft to which the impeller and the motor are connected; a gap sensor measuring a displacement change of the rotation shaft as a frequency change; a temperature compensation sensor determining a frequency compensation value according to a temperature change around the gap sensor; and a control unit calculating a displacement amount of the rotation shaft by reflecting the frequency compensation value provided by the temperature compensation sensor and the frequency change measured by the gap sensor.

Pneumatic air systems for use onboard aircraft include a compressor configured to receive air from an air supply and increase a pressure of said received air to generate compressed air, a heat exchanger configured to receive the compressed air as a first working fluid and a treating air as a second working fluid, the heat exchanger configured to convert the compressed air to compressed and temperature treated air, one or more aircraft systems configured to receive the compressed and temperature treated air, and a surge prevention circuit arranged to prevent surge of air at the compressor, wherein the surge prevention circuit comprises a mechanical valve that is actuated based on a detected pressure within a sense line operably coupled to the mechanical valve.