A system and a method for automatically correcting a rotational speed of a motor of a fan are provided. After the fan is moved from an open space to a closed space, a sample and hold circuit samples and holds working periods of a driving signal by which the motor is driven to rotate at a first rotational speed as a first sampled working period, and a working period of a driving signal by which the motor is driven to rotate at a second rotational speed. An arithmetic circuit calculates a difference between the first sampled working period and a first reference working period, and a difference between the second sampled working period and a second reference working period. The arithmetic circuit calculates other working periods of driving signals by which the motor is driven to rotate at other rotational speeds based on the differences.

A system includes a vertical molten sulfur pump assembly that includes a top portion adjacent to a first end of the vertical molten sulfur pump assembly and a bottom portion adjacent to a second end of the vertical molten sulfur pump assembly. A pump motor is disposed in the top portion, an impeller is disposed in the bottom portion within an impeller casing, and a shaft is disposed within a central column and connecting the pump motor with the impeller. A pump inlet is disposed at the second end below the impeller casing. The pump inlet and the impeller casing are configured to be immersed in molten sulfur. The vertical molten sulfur pump assembly is configured to pump the molten sulfur into the inlet and upwards through a discharge passageway by rotation of the impeller. A vibration sensor and a temperature sensor are disposed on an external surface of the bottom portion, on or proximate to the impeller casing and the pump inlet. The temperature sensor is configured to measure a temperature of the molten sulfur proximate to the pump inlet. The vibration sensor includes a substrate comprising a polymer and a resonant layer disposed on a surface of the substrate. The resonant layer includes an electrically conductive nanomaterial and is configured to produce a resonant response in response to receiving a radio frequency signal.

A sensor includes a radio frequency interrogator, a responsive patch, a radio frequency resonance detector, and a transmission line. The radio frequency interrogator is configured to produce an electromagnetic interrogation pulse having a first frequency. The responsive patch includes a substrate and a resonant layer disposed on a surface of the substrate. The substrate includes a polymer. The resonant layer includes an electrically conductive nanomaterial. The resonant layer is configured to resonate at the first frequency in response to receiving the electromagnetic interrogation pulse. The radio frequency resonance detector is configured to detect a resonating response of the responsive patch. The transmission line couples the responsive patch to the radio frequency resonance detector. The transmission line is configured to transmit the resonating response of the responsive patch to the radio frequency resonance detector.

Embodiments of the present disclosure relate to a refrigeration system that includes a compressor configured to circulate refrigerant along a refrigerant loop, a motor configured to drive the compressor, and a variable speed drive coupled to the motor and configured to supply power to the motor. The variable speed drive includes a primary winding of a step down transformer coupled to an alternating current (AC) power source, a first secondary winding of the step down transformer, where the first secondary winding is configured to supply power at a variable supplied voltage to the motor when the motor operates below a threshold voltage, and a second secondary winding of the step down transformer, where the second secondary winding is configured to supply power at a fixed supplied voltage when the motor operates at or above the threshold voltage.

Disclosed is a fan. The fan includes a support; a first motor installed on the support, the first motor having a first rotation shaft; a first blade installed on the first rotation shaft; a second motor installed on the support, the second motor having a second rotation shaft and being coaxial with the first motor; a second blade installed on the second rotation shaft, a tilt direction of the second blade being opposite to a tilt direction of the first blade; and an electric control board electrically connected to the first motor and the second motor and configured to control a relative rotation of the first motor and the second motor.

A system for controlling operation of a ceiling fan is provided. The ceiling fan includes a fan device and a light device, and can be operated via a user operation module that is to be operated by direct operation, or a wireless receiver module that receives a wireless control signal. Within a predetermined control duration from the time of activation, the ceiling fan can, upon receipt of an operation signal from the user operation module or a wireless control signal from the wireless receiver module, switch to operate in a mode where the ceiling fan is controlled via one of the user operation module and the wireless receiver module that corresponds to the signal received thereby.

A system for controlling operation of a ceiling fan is provided. The ceiling fan includes a fan device and a light device, and can be operated via a user operation module that is to be operated by direct operation, or a wireless receiver module that receives a wireless control signal. Within a predetermined control duration from the time of activation, the ceiling fan can, upon receipt of an operation signal from the user operation module or a wireless control signal from the wireless receiver module, switch to operate in a mode where the ceiling fan is controlled via one of the user operation module and the wireless receiver module that corresponds to the signal received thereby.

A variable geometry turbocharger (100) includes a bearing housing (10) including a bearing-housing side support portion (40) configured to support a radially outer portion (38) of a nozzle mount (16) from a side opposite to a scroll flow passage (4) in an axial direction of a turbine rotor (2), and wherein at least one of the following condition (a) or (b) is satisfied: (a) the bearing-housing side support portion (40) includes at least one bearing-housing side recess portion (46) formed so as to be recessed in the axial direction so as not to be in contact with the radially outer portion (38); (b) the radially outer portion (38) of the nozzle mount (16) includes at least one nozzle-mount side recess portion (62) formed so as to be recessed in the axial direction so as not to be in contact with the bearing-housing side support portion (40).

A cooling fan monitoring circuit for monitoring and immediately alerting the user of the activation of a cooling fan motor and blade assembly providing notice of the shutting down of equipment requiring cooling to prevent overheating and damage to the equipment. The circuit is capable of monitoring multiple cooling fans and shuts down equipment if any one of the cooling fans ceases function, fails a preset condition, or the equipment reaches a preset temperature.

An apparatus for circulating air in a space using a fan, a sensor for sensing an ambient condition, and a user input for inputting a desired condition. A controller is configured for controlling the fan to operate substantially at a first fan speed for the desired condition, and controlling the fan to operate substantially at a second fan speed for the sensed ambient condition. Related methods are also disclosed.