Methods and systems for controlling windmilling in an engine are described. An electric starter motor is coupled to the engine, a circuit element is coupled to the electric starter engine and to a DC signal source, and a control system coupled to the engine and to the circuit element. The control system is configured for: determining whether the engine is in a windmilling state; when the engine is in a windmilling state, commanding the circuit element to apply a DC signal to the electric starter motor; and modulating the DC signal applied to the electric starter motor to control a level of rotational motion of the engine.

A valve actuator includes a motor, an AC power source, a DC braking system, and a control system. The control system is configured to control the AC power source to apply an AC voltage to the motor to drive a valve toward a closed position. The control system is configured to disconnect the AC voltage from the motor before the valve reaches the closed position. The control system is configured to control the DC braking system to apply a DC voltage to the motor to stop motion of the valve.

The invention relates to a control apparatus for a refrigerator compressor having at least one two-phase AC asynchronous motor (K1, K2), having mains connection means (10) for connection to a preferably public voltage supply network which nominally provides a mains AC voltage of between 85 V and 264 V, in particular between 100 V and 230 V, first voltage converter means (14) which are connected downstream of the mains connection means and are intended to generate an intermediate voltage, in particular an intermediate DC voltage, from the mains AC voltage, second voltage converter means (16-1, 16-2) which are connected downstream of the first voltage converter means and are intended to generate an output signal which is independent of a level and a mains frequency of the mains AC voltage, in particular has a constant voltage and/or frequency in periods, and is intended to control the refrigerator compressor with an AC voltage of a plurality of differently predefinable voltage levels, wherein the mains connection means are assigned voltage detector means (12) for capturing the mains AC voltage, the detector output signal from which can be evaluated by the second voltage converter means or control means (24) assigned to the latter for the purpose of generating a mains-voltage-dependent maximum value for a current of the output signal.

A motor arrangement comprising: motor having a rotor, a stator, and a plurality of windings mounted on one of the rotor and the stator for acting on the other of the rotor and the stator, and a plurality of inputs coupled to the windings; and control circuit configured to operate in a riving mode in which it dynamically energises the windings via the motor inputs so as to cause the rotor to rotate relative to the stator, the control circuit being further configured to operate in a braking mode in which it continually connects at least a first and a second one of the windings to a common rail to form a closed current path to induce braking of the rotor relative to the stator, wherein the control circuit is configured to enter the braking mode in response to a trigger exogenous to the motor indicative of a fault condition.

A motor arrangement comprising: motor having a rotor, a stator, and a plurality of windings mounted on one of the rotor and the stator for acting on the other of the rotor and the stator, and a plurality of inputs coupled to the windings; and control circuit configured to operate in a riving mode in which it dynamically energises the windings via the motor inputs so as to cause the rotor to rotate relative to the stator, the control circuit being further configured to operate in a braking mode in which it continually connects at least a first and a second one of the windings to a common rail to form a closed current path to induce braking of the rotor relative to the stator, wherein the control circuit is configured to enter the braking mode in response to a trigger exogenous to the motor indicative of a fault condition.

An electric motor connected to a switching device is braked from an active operating state by actuating a semiconductor switch arranged in parallel with an electromechanical switch to reduce a current intensity in the electromechanical switch, opening the electromechanical switch, blocking the semiconductor switch for an adjustable period, determining a resulting torque of the electric motor, and determining an actuation time for braking the electric motor based on the resulting torque and actuating the semiconductor switch at the actuation time. The resulting torque is opposite a present direction of rotation of the electric motor at the actuation time. The semiconductor switch is turned on for an adjustable actuation period. Also disclosed are a computer program product and a soft starter configured to implement the described method.

An electric motor connected to a switching device is braked from an active operating state by actuating a semiconductor switch arranged in parallel with an electromechanical switch to reduce a current intensity in the electromechanical switch, opening the electromechanical switch, blocking the semiconductor switch for an adjustable period, determining a resulting torque of the electric motor, and determining an actuation time for braking the electric motor based on the resulting torque and actuating the semiconductor switch at the actuation time. The resulting torque is opposite a present direction of rotation of the electric motor at the actuation time. The semiconductor switch is turned on for an adjustable actuation period. Also disclosed are a computer program product and a soft starter configured to implement the described method.

A method for using an active braking mechanism to halt the motion of a treadmill belt, or other exercise machine system, when the engine ceases driving it and to hold the belt, or system, after the brake is engaged. The types of braking systems will generally utilize at least one but often two or more forms of electrical braking. Frictional braking systems may also be present, but the electrical braking systems will generally be primarily responsible for braking the belt at high inclines.

A method for using an active braking mechanism to halt the motion of a treadmill belt, or other exercise machine system, when the engine ceases driving it and to hold the belt, or system, after the brake is engaged. The types of braking systems will generally utilize at least one but often two or more forms of electrical braking. Frictional braking systems may also be present, but the electrical braking systems will generally be primarily responsible for braking the belt at high inclines.

A regenerative braking system includes a motor configured to rotate at a variable rotational speed in response to receiving power from a three-phase power supply, and a regenerative braking circuit in signal communication with the three-phase power supply to control the rotational speed of the motor. A brake controller is in signal communication with the regenerative braking circuit and is configured to selectively operate the regenerative braking circuit in a plurality of different braking modes based on the rotational speed of the motor.