A remote control system for forward/reverse rotation of a fan includes a remote control and a forward-reverse rotation control unit. The remote control includes an operation module, and a first control module capable of outputting an operation signal which corresponds to an operation condition of the operation module. The operation signal can switch between a forward rotation mode and a reverse rotation mode to correspond to the operation condition of the operation module. The forward-reverse rotation control unit includes a double-pole relay that is controllable to switch between a first mode and a second mode and that is used to provide electric power to the fan, and a second control module that controls the double-pole relay to switch modes according to the operation signal, thereby making a rotational direction of the fan correspond to the operation of the operation module.

A lightweight impeller is provided for use in a pressurised gas source for a CPAP or other breathing assistance apparatus. The impeller can be shroudless or otherwise lightweight.

A fan apparatus may include a frame, a fan, and a drive mechanism. The fan may be supported for rotation relative to the frame and may include a fan shaft and a plurality of blades extending outward from the fan shaft. The drive mechanism may include a driven wheel, a drive shaft, a first drive wheel, a second drive wheel, and a torque-transmission loop. The driven wheel may be mounted on the fan shaft. The drive shaft may be supported for rotation relative to the frame. The first drive wheel may be mounted on the drive shaft. The second drive wheel may be mounted on the drive shaft. The torque-transmission loop may be engaged with the driven wheel and a selected one of the first and second drive wheels.

A long-distance speed control system for a brushless DC motor of a fan is provided. The long-distance speed control system includes a switch connected with a mains power supply, a switch circuit, a voltage detection module, a power cord, a processing unit, and a drive unit, which can control the multi-stage rotational speed of the motor. In the field of brushless DC motors for fans, there is no need to use analog-to-digital conversion chips between the mains power supply and the processor, having the advantages of low cost, environmental protection, and reduction of waste of earth resources. Besides, the switch, the switch circuit and the power cord can withstand the mains power supply, having the advantages of less signal attenuation and long-distance transmission.

A head-mountable flow generator is configured to deliver a flow of breathable gas at a continuously positive pressure with respect to ambient air pressure to a patient interface in communication with an entrance to a patient's airways including at least an entrance of the patient's nares, while the patient is sleeping, to ameliorate sleep disordered breathing. The flow generator includes a motor, an impeller assembly and housing that encases the motor and the impeller assembly. The housing is configured to be mounted on the patient's head and comprises an inlet to receive the flow of breathable gas and a pair of opposing outlets to deliver the flow of breathable gas. In addition, the impeller assembly is configured to pressurize the flow of breathable gas received from the inlet, and the housing is configured to convey the pressurized flow of breathable gas through both outlets.

A heating, ventilation, air conditioning, and refrigeration (HVACR) system includes a compressor with a gas bearing supplied with compressed gas and a controller. The controller is configured to determine an inlet pressure and outlet pressure of the gas bearing, determine a maximum speed limit based on the inlet pressure and the outlet pressure, and prevent the compressor from operating at a speed that is greater than the maximum speed limit. A method of controlling a compressor includes calculating a maximum speed limit based on an inlet pressure and an outlet pressure of the gas bearing. The method also includes in response to determining that a speed setting is greater than the maximum speed limit, adjusting operation of the compressor such that a speed of the compressor is at or below the maximum speed limit.

A system of interlocks for controlling flow of low temperature process streams in a manufacturing process through a cold box to equipment or piping not specified for such temperatures by opening and closing valves and starting and stopping pumps. At least one interlock affects streams heated in the cold box. At least one interlock affects the streams cooled in the cold box. The interlocks are activated by temperatures of process lines to prevent exposure of equipment and piping to low temperatures while preventing the shutdown of the cold box. An override controller including a predictive failure capability is also provided.

Provided area second-order sliding mode observation-based fan power control method and system. The method includes: calculating, by second-order sliding mode observation, an observed rotational speed value of a fan, and calculating a maximum power reference current corresponding to maximum power of the fan according to a relational expression between the rotational speed and maximum power point; and performing, by controlling a Pulse Width Modulation (PWM) switch to be toggled, system Maximum Power Point Tracking (MPPT) according to the maximum power reference current, so as to control the fan to operate stably at the maximum power point.

The invention concerns a control module (15) of a blower for a heating and/or ventilation and/or air conditioning device, in particular for a motor vehicle, the blower being configured to generate an airflow, and the control module (15) being configured to control the blower and comprises a heat sink (157), a heat dissipation base (158) and at least one active power electronic component (153) mounted on the heat dissipation base (158). According to the invention, the heat sink (157) comprises a housing (156) for receiving at least a part of the heat dissipation base (158). The heat sink base (158) is mounted by press-fitting into said housing (156). The invention also relates to a corresponding heating and/or ventilation and/or air conditioning device.

A computing device is provided, including one or more processing devices, one or more temperature sensors, a fan, and a fan tachometer. The one or more processing devices may be configured to execute an application program. While executing the application program, the one or more processing devices may be further configured to collect performance data including temperature data received from the one or more temperature sensors and fan speed data received from the fan tachometer. The one or more processing devices may be further configured to generate a fan control signal at least in part by applying a machine learning model to the performance data. The one or more processing devices may be further configured to control the fan according to the fan control signal.