Disclosed are exemplary embodiments of systems and methods for controlling inducer motor speed. In an exemplary embodiment, a method includes changing stator voltage of an inducer motor (e.g., by changing a firing angle of a triac, using a transistor, a silicon controlled rectifier or semiconductor controlled rectifier (SCR), other switching device, etc.); determining actual inducer motor speed (e.g., by using a hall effect sensor or other speed sensor, etc.); and after determining the actual inducer motor speed, changing the motor stator voltage (e.g., by changing the firing angle of the triac, etc.) to a value at which the actual inducer motor speed is controllably regulated and/or maintained substantially at a set speed.

A load control device may control power delivered from a power source, such as an alternating-current (AC) power source, to at least two electrical loads, such as a lighting load and a motor load. The load control device may include multiple load control circuit, such as a dimmer circuit and a motor drive circuit, for controlling the power delivered to the lighting load and the motor load, respectively. The load control device may adjust the rotational speed of the motor load in a manner so as to minimize acoustic noise generated by the load control device and reduce the amount of time required to adjust the rotational speed of the motor load. The load control device may remain powered when one of the electrical loads (e.g., the lighting load) has been removed (e.g., electrically disconnected or uninstalled) and/or has failed in an open state (has “burnt out” or “blown out”).

A load control device may control power delivered from a power source, such as an alternating-current (AC) power source, to at least two electrical loads, such as a lighting load and a motor load. The load control device may include multiple load control circuit, such as a dimmer circuit and a motor drive circuit, for controlling the power delivered to the lighting load and the motor load, respectively. The load control device may adjust the rotational speed of the motor load in a manner so as to minimize acoustic noise generated by the load control device and reduce the amount of time required to adjust the rotational speed of the motor load. The load control device may remain powered when one of the electrical loads (e.g., the lighting load) has been removed (e.g., electrically disconnected or uninstalled) and/or has failed in an open state (has “burnt out” or “blown out”).

An electric motor system is described. The electric motor system includes a drive circuit including an inverter configured to supply variable frequency current and a contactor configured to supply line frequency current. The electric motor system also includes an electric motor coupled to the drive circuit wherein the electric motor is communicatively coupled to a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor, thereby operating the electric motor at a motor speed, and determine, based upon at least one input parameter, a maximum potential motor speed the inverter can achieve. The controller is also configured to receive a command to operate the electric motor at line frequency current and control the drive circuit to transition from supplying variable frequency current to supplying line frequency current before the maximum potential motor speed the inverter can achieve is reached.

An electric motor system is described. The electric motor system includes a drive circuit including an inverter configured to supply variable frequency current and a contactor configured to supply line frequency current. The electric motor system also includes an electric motor coupled to the drive circuit wherein the electric motor is communicatively coupled to a controller. The controller is configured to control the inverter to supply variable frequency current to the electric motor, thereby operating the electric motor at a motor speed, and determine, based upon at least one input parameter, a maximum potential motor speed the inverter can achieve. The controller is also configured to receive a command to operate the electric motor at line frequency current and control the drive circuit to transition from supplying variable frequency current to supplying line frequency current before the maximum potential motor speed the inverter can achieve is reached.

A single-phase brushless DC motor includes a rotor rotatable about a central axis, a stator including salient pole portions, a stator core including a slot between the salient pole portions, and a winding wound around the salient pole portions, the stator opposing the rotor with an air gap interposed therebetween, and a substrate fixed to the stator and including a driver to perform energization control of the winding. The driver includes a Hall element to acquire a timing of the energization control. The substrate includes a Hall IC to detect a circumferential position of the rotor separately from the driver.

Disclosed are exemplary embodiments of systems and methods for controlling inducer motor speed. In an exemplary embodiment, a method includes changing stator voltage of an inducer motor (e.g., by changing a firing angle of a triac, using a transistor, a silicon controlled rectifier or semiconductor controlled rectifier (SCR), other switching device, etc.); determining actual inducer motor speed (e.g., by using a hall effect sensor or other speed sensor, etc.); and after determining the actual inducer motor speed, changing the motor stator voltage (e.g., by changing the firing angle of the triac, etc.) to a value at which the actual inducer motor speed is controllably regulated and/or maintained substantially at a set speed.

Disclosed are exemplary embodiments of systems and methods for controlling inducer motor speed. In an exemplary embodiment, a method includes changing stator voltage of an inducer motor (e.g., by changing a firing angle of a triac, using a transistor, a silicon controlled rectifier or semiconductor controlled rectifier (SCR), other switching device, etc.); determining actual inducer motor speed (e.g., by using a hall effect sensor or other speed sensor, etc.); and after determining the actual inducer motor speed, changing the motor stator voltage (e.g., by changing the firing angle of the triac, etc.) to a value at which the actual inducer motor speed is controllably regulated and/or maintained substantially at a set speed.

An embodiment relates to a switchgear for a single-phase motor and a three-phase motor, the switchgear including a processing unit and a first, second and third current path, the first and third current path each including a current transformer. The processing unit is adapted to detect the current I.sub.1 of the first current path and the current I.sub.3 of the third current path. To provide a cost-effective switchgear for a one-phase motor and a three-phase motor which is adapted to identify the failure of every single phase in the three-phase operation and a phase failure in the one-phase operation, the processing unit is designed such as to detect the currents I.sub.1, I.sub.3 of the first and third current path and to determine, based on the phase shift between the detected currents I.sub.1, I.sub.3 of the first and third current path in which operating mode the switchgear is operated.

An embodiment relates to a switchgear for a single-phase motor and a three-phase motor, the switchgear including a processing unit and a first, second and third current path, the first and third current path each including a current transformer. The processing unit is adapted to detect the current I.sub.1 of the first current path and the current I.sub.3 of the third current path. To provide a cost-effective switchgear for a one-phase motor and a three-phase motor which is adapted to identify the failure of every single phase in the three-phase operation and a phase failure in the one-phase operation, the processing unit is designed such as to detect the currents I.sub.1, I.sub.3 of the first and third current path and to determine, based on the phase shift between the detected currents I.sub.1, I.sub.3 of the first and third current path in which operating mode the switchgear is operated.