A control circuit for an induction motor operates to determine whether the inductor motor is of the three-phase type or single-phase type. If three-phase, a variable frequency drive operation is implemented. If single-phase, a closed loop current control process is implemented. The closed loop current control process includes an operation by the control circuit to measure winding resistances and determine a turns ratio for the main and auxiliary motor windings. The turns ratio is used in the closed loop current control process to scale a measurement of current in the auxiliary winding for the purpose of generating the control voltage for the auxiliary winding. Phase of the current in the windings is further processed to generate a phase control signal.

Controller is provided for electromechanical actuator such as an electric brake actuator having a motor driven in response to motor drive signal generated by controller. Controller includes first current limiter and second current limiter. First current limiter limits current command to maximum current limit in response to detecting that current command at least one of exceeds maximum current limit setpoint or is less than minimum current limit setpoint. Second current limiter further limits current and to limited current command in response to detecting that current command exceeds topper current detection limit for specified time duration. Controller may further include intermediate current limiter between first and second current limiters for further limiting current command from first current limiter in response to detecting current command from first current limiter at least one of exceeds maximum power limit setpoint or is less than minimum power limit setpoint.

Starter system for an electric motor (M) supplied by an electrical network (1), the starter system comprising an electronic control circuit (7) and an electronic switch (10) for controlling one phase of the motor (M), the electronic switch (10) being controlled by the control circuit (7). The starter system comprises a sensor (3) intended to deliver an analogue signal (4) that is representative of the derivative of a current flowing through the phase of the motor (M), a detection board (5) comprising means for transforming said analogue signal (4) into a binary signal (6) that is representative of the changes in sign of said analogue signal, and comprising means for transmitting said binary signal to the control circuit (7), so as to optimize the control of the electronic switch (10).

A motor is connectable to a single-phase AC power supply and forms a hermetic compressor. The motor includes a main circuit connected in parallel with the auxiliary circuit, and a winding structure having a main winding arranged as part of the main circuit and an auxiliary winding arranged as part of the auxiliary circuit. The motor includes a rotor arranged to be rotated by a current in the winding structure. To provide a motor durable and cheap to manufacture and to ensure a suitable response to overload situations, the auxiliary circuit has a first section and a second section extending in parallel where an NTC is inserted in the first section. A PTC is inserted in the second section, and a relay is arranged to activate and deactivate current in the first section of the auxiliary circuit based on a current level in the main circuit.