A motor control circuit is provided for connecting or disconnecting an AC voltage to an AC motor, having a switch having two switch contacts, configured to respond to a process variable and move between open and closed switch contact positions to connect or disconnect the AC voltage to the AC motor; and a snubber circuit arranged across the switch contacts in parallel with the AC motor, and configured to respond to motor inductance when the switch is moved between the open and closed switch contact positions, and provide arc suppression in the switch by dissipating energy stored in the motor inductance. The snubber circuit may include a network having a resistor connected in series with a capacitor, or a metal oxide varistor, or a transient voltage suppressor.

A system including an electric motor of a compressor system and a controller is disclosed. The electric motor includes a switch configured to provide line frequency power to the electric motor to drive the electric motor at a full speed, and an inverter to provide variable frequency power to the electric motor to drive the electric motor at a variable speed. The controller is configured to determine whether the switch is closed in response to powering up the electric motor and before supplying the variable frequency power to the electric motor from the inverter. The controller is configured to prevent supply of the variable frequency power to the electric motor from the inverter to prevent damage to the inverter based on the determining that the switch is closed and generate an alert notification to notify a user of a fault in the switch.

There is provided an induction machine (100) comprising a rotor (120); a stator (140); and a phase-shift oscillator (160). The stator comprises: a first winding (141); and a second winding (142), arranged at a first angle (101) relative to said first winding. The phase-shift oscillator comprises: a transistor (170), the transistor (170) being a high-electron mobility transistor, HEMT; and a phase-shift network (180). The first winding is connected to a first node (181) of the phase-shift network and wherein the second winding is connected to a second node (182) of the phase-shift network, wherein the phase-shift oscillator is configured to provide a first phase electric signal at the first node and a second phase electric signal at the second node, wherein a difference between the first and second phase corresponds to the first angle. There is also provided an electric aircraft propulsion system comprising the induction machine.

A converter for an air conditioning system includes a rectifier section configured to receive a multiphase, AC input voltage; a voltage regulator section coupled to the rectifier section, the voltage regulator section configured to control a DC output voltage across a positive DC bus and a negative DC bus; and a controller in communication with the rectifier section and the voltage regulator section, the controller configured to control the converter in a first mode or a second mode in response to a transient detected in the converter.

An electronic starting switch assembly and control methods for a dryer having a split-phase induction motor. The assembly comprises a microcontroller unit (MCU) configured to execute a control method that dynamically manages the motor's operation by monitoring the forward magnitude current. The MCU determines a stabilized startup forward magnitude current and calculates a crossover condition, allowing for precise control of the motor's transition to single-phase operation by disconnecting the auxiliary winding and connecting the heater element based on real-time forward magnitude current analysis and processing. The system can also monitor for overload conditions indicative of rotor speed drops and can re-engage the auxiliary winding to maintain motor performance. The assembly includes a housing with a heat-sink for efficient thermal management and environmental protection of electronic components. The disclosed method provides a robust solution for efficient dryer operation by ensuring accurate control of motor start-up, running conditions, and overload protection.

An electronic starting switch assembly and control methods for a dryer having a split-phase induction motor. The assembly comprises a microcontroller unit (MCU) configured to execute a control method that dynamically manages the motor's operation by monitoring the forward magnitude current. The MCU determines a stabilized startup forward magnitude current and calculates a crossover condition, allowing for precise control of the motor's transition to single-phase operation by disconnecting the auxiliary winding and connecting the heater element based on real-time forward magnitude current analysis and processing. The system can also monitor for overload conditions indicative of rotor speed drops and can re-engage the auxiliary winding to maintain motor performance. The assembly includes a housing with a heat-sink for efficient thermal management and environmental protection of electronic components. The disclosed method provides a robust solution for efficient dryer operation by ensuring accurate control of motor start-up, running conditions, and overload protection.