A position management apparatus includes motors connected to a power supply; a position detecting device connected to the power supply and detecting the rotational position of the motors or the drive position of driving members driven by the motors; position storage devices connected to the power supply and storing the rotational position or the drive position detected by the position detecting devices; and a power cut-off delay circuit for keeping the position detecting devices and the position storage devices connected to the power supply even if the power switch is shut off from a conducting state, and for storing the rotational position or the drive position of the position storage devices after the motor has lost its rotational speed.

A system, in one embodiment, may include a system includes a ground fault detection system. The ground fault detection system includes a linear filter configured to receive one or more signals from a static starter system during operations of the static starter system and to produce a linear filter output. The ground fault detection system further includes a rectifier configured to rectify the linear filter output and to produce a rectifier output, and a gain system configured to multiply the rectifier output by a factor to produce a gain output. The ground fault detection system additionally includes a fault indicator system configured to indicate a ground fault based on the gain output, wherein the ground fault detection system is configured to command an action based on the ground fault.

A system, in one embodiment, may include a system includes a ground fault detection system. The ground fault detection system includes a linear filter configured to receive one or more signals from a static starter system during operations of the static starter system and to produce a linear filter output. The ground fault detection system further includes a rectifier configured to rectify the linear filter output and to produce a rectifier output, and a gain system configured to multiply the rectifier output by a factor to produce a gain output. The ground fault detection system additionally includes a fault indicator system configured to indicate a ground fault based on the gain output, wherein the ground fault detection system is configured to command an action based on the ground fault.

The present disclosure relates to a fan motor control device comprising a control signal input for applying a rotational speed control voltage as the control signal input signal and a control signal output for picking off a control signal output signal for connecting to a fan motor, where modulation means are connected downstream from the control signal input, said modulation means being designed to convert the control signal input signal into a digital and/or pulsed modulation input signal, and isolated transmission means are connected downstream therefrom, which transfer the digital and/or pulsed modulation input signal into a digital and/or pulsed modulation output signal isolated from the control signal input, which is converted into the control signal output signal that can be picked off on the control signal output by means of demodulation means connected downstream from the transmission means.

A first torque estimator determines a first torque estimation value according to a cross product method, and a second torque estimator determines a second torque estimation value according to an energy method. A torque weight adjuster adjusts, using a weighting coefficient calculated in accordance with a predetermined condition, weightings respectively applied to these two types of torque estimation values, and outputs a torque estimation value.

A control method for a centrifuge is performed by a motor drive unit to drive a motor of the centrifuge using pulses from an angle sensor. The method has a start phase, a regulated acceleration phase, a holding phase, a regulated deceleration phase, a regulated gentle deceleration phase, and a position adjustment phase.

A field of controlling pumps and pumping plants and installations, such as electrical devices and installations used for controlling pumps and pumping plants and installations, and more particularly to a method and an arrangement for starting pumping with a submersible centrifugal pump for pumping fluid. In the arrangement for starting pumping with a submersible centrifugal pump for pumping fluid, the arrangement including a submersible centrifugal pump and an electric drive apparatus arranged for controlling the motor of the submersible centrifugal pump, the electric drive apparatus is arranged: for starting an accelerating ramp for ramping up the speed of the motor of the submersible centrifugal pump; for monitoring the torque of the motor of the submersible centrifugal pump versus pump motor speed; and upon detecting a significant increase in the derivate of monitored torque versus pump motor speed, for starting an operational pumping ramp for the motor of the submersible centrifugal pump.

A field of controlling pumps and pumping plants and installations, such as electrical devices and installations used for controlling pumps and pumping plants and installations, and more particularly to a method and an arrangement for starting pumping with a submersible centrifugal pump for pumping fluid. In the arrangement for starting pumping with a submersible centrifugal pump for pumping fluid, the arrangement including a submersible centrifugal pump and an electric drive apparatus arranged for controlling the motor of the submersible centrifugal pump, the electric drive apparatus is arranged: for starting an accelerating ramp for ramping up the speed of the motor of the submersible centrifugal pump; for monitoring the torque of the motor of the submersible centrifugal pump versus pump motor speed; and upon detecting a significant increase in the derivate of monitored torque versus pump motor speed, for starting an operational pumping ramp for the motor of the submersible centrifugal pump.

A voltage divider circuit is configured by a resistor having one end connected to a positive electrode of a battery configuring a power source and another end connected to a first terminal that is a motor terminal on one side of a wiper motor, and a FET having one end connected to the first terminal and another end grounded. The voltage divider circuit lowers a voltage of the battery to a test voltage that does not cause the wiper motor to rotate. A microcomputer detects a detected voltage that is a voltage output from the voltage divider circuit to a second terminal that is a motor terminal on the other side of the wiper motor via the first terminal of the wiper motor and the wiper motor, and computes a motor terminal voltage, this being a potential difference between the first terminal and the second terminal, from the detected voltage.

A motor starter and a method for starting an electric motor are disclosed. In an embodiment, the motor starter includes a phase gating unit and a control unit. The phase gating unit is configured to be deactivated via the control unit after an activity period of the phase gating unit has elapsed and is configured to be deactivated during operation after the activity period has elapsed.