A method for controlling a DC pump motor, preferably a brushed DC motor for pumping lubricant, which motor is controlled by a pulse-width modulated (PWM) control signal, wherein current parameters are acquired in an acquisition step and a duty cycle (D) of the PWM control signal (S.sub.PWM) is adapted and/or changed on the basis of the detected parameters in an adaptation step, wherein the acquisition of current parameters comprises at least the acquisition of a current input voltage (U.sub.B).

A hydraulic pressure supply system includes a mechanical oil pump; an electric oil pump; an electric motor that drives the electric oil pump; a control device that controls the operation of the electric oil pump; and a hydraulic pressure measurement circuit that measures a hydraulic pressure of the outlet-side pipe of the electric oil pump. The control device starts supplying electric power to the electric motor to thereby start drive of the electric oil pump before the mechanical oil pump stops operating, and limits the power-supply current to the electric motor to a first current or less during a time period between the start of the drive of the electric oil pump and the time when the hydraulic pressure measured by the hydraulic pressure measurement circuit exceeds a prescribed outlet hydraulic pressure.

An inverter is disposed at a position on the upstream side relative to a compression mechanism along the flow of a refrigerant and the position cooled by the refrigerant. A motor is disposed at a position heated by the refrigerant compressed by the compression mechanism. A control device changes an upper limit value of a driving current supplied to the motor on the basis of at least one of first information relating to the temperature of the motor or second information relating to the temperature of the inverter.

A current value determination device provided with: a capacitor current computation unit for computing the capacitor current of a capacitor included in a high-voltage circuit that drives a motor, on the basis of the input voltage of an inverter included in the high-voltage circuit and the revolution speed of the motor; and a capacitor current determination unit for determining the value of capacitor current on the basis of the input voltage of the inverter, the revolution speed of the motor, the capacitor current computed by the capacitor current computation unit, and a prescribed model for determination.

A water pumping control device may include a primary power source and a secondary power source. The primary power source may be configured to provide a primary power input to a processing unit, and the secondary power source may be configured to provide a secondary power input to the processing unit. A primary pump and a secondary pump may be in communication with the processing unit, and the primary pump and the secondary pump may each be variable in speed. The primary pump and the secondary pump may each be in fluid communication with a sump so that when a pump is activated, the pump may remove water from the sump. A water level sensor may be in communication with the processing unit, and the water level sensor may be configured to provide a water level input describing a water level in the sump to the processing unit.

Some embodiments of the invention provide a pumping system for at least one aquatic application. The pumping system includes a pump, a motor coupled to the pump, a user interface associated with the pump designed to receive input instructions from a user, and a controller in communication with the motor. The controller determines a power parameter associated with the motor and compares the power parameter to a predetermined threshold value. The controller triggers a safety vacuum release system based on the comparison of the power parameter and the threshold value.

A control device for a compressor includes an operation stop control unit that stops the compressor in a procedure different from a normal stop request signal when a signal different from the normal stop request signal that requests the compressor to stop in a predetermined procedure and a forced stop request signal from a device including the compressor is detected. The operation stop control unit stops the compressor in the different procedure according to a speed of the compressor when the forced stop request signal is detected.

A light load abnormality determination method for an electric oil pump (3) that circulates oil to an object to be cooled by the electric oil pump driven by a motor (11), the method comprising: a detection step (41) to detect a current flowing through the motor, a voltage supplied to the motor, and a rotation speed of the motor; a calculation step (42) to calculate a piping resistance equivalent value or a reciprocal value of the piping resistance equivalent value, as a load evaluation value for light load abnormality determination, based on the current, the voltage and the rotation speed detected by the detection step; and a light load abnormality determination step (44) to determine a light load abnormality of the electric oil pump based on the load evaluation value.

A compressor fault diagnostic apparatus including a current sensing unit to sense a current flowing through a motor of the compressor, a fault diagnostic unit to determine whether or not the motor performs a reverse rotation based on the current flowing through the motor, and a cut-off unit to remove power based on a determination of the fault diagnostic unit.

An electric pump includes a pump unit, a motor and a controller. The pump unit is configured to pump fluid by a rotating operation. The motor is a brushless direct-current motor and configured to rotationally drive the pump unit. The controller is configured to control a current to be supplied to the motor. The controller is configured to switch between voltage control for controlling the current to be supplied to the motor based on a target voltage and current control for controlling the current to be supplied to the motor based on a target current.