A method of driving a pump is used in a pressure-applying apparatus, the apparatus including a flow passage, a pump configured to impart pressure into the flow passage, an opening and closing valve configured to open and close the flow passage, a pressure detector configured to detect pressure in the flow passage, and an atmospheric air open valve configured to open an interior of the flow passage to atmospheric air. The method includes driving the pump after closing the opening and closing valve and opening the atmospheric air open valve, and evaluating a state of the pump, based on one of: the pressure detected by the pressure detector at a time at which a predetermined time period has elapsed after closing the atmospheric air open valve, and a time from closing of the atmospheric air open valve until detection of a predetermined pressure by the pressure detector.

A system includes a chemical storage tank, a pipeline, a pump, a first electrostatic probe, and a control unit. The pipeline is connected to the chemical storage tank. The pump is connected to the pipeline and configured to pump a chemical solution from the chemical storage tank into the pipeline. The first electrostatic probe is coupled to the pump and configured to measure an electrostatic voltage of the pump. The control unit is coupled to the first electrostatic probe and configured to obtain a measurement of an electrostatic voltage from the first electrostatic probe.

A system, method, and computer-readable medium for determining the flow rate and fluid density in an electrical submersible pump (ESP) and controlling the ESP based on the flow rate and density. In one implementation, an ESP system includes an ESP, drive circuitry, a current sensor, a voltage sensor, and a processor. The ESP includes an electric motor. The drive circuitry is electrically coupled to the ESP and is configured to provide an electrical signal to power the ESP. The current sensor is configured to measure a current of the electrical signal. The voltage sensor is configured to measure a voltage of the electrical signal. The processor is configured to calculate speed of a shaft of the electric motor based on a frequency induced by rotation of the motor detected in the current. The processor is also configured to calculate a density of fluid in the ESP based on the speed.

An air compressor includes a compressor main body that compresses air; a storage tank that stores the gas compressed by the compressor main body; a motor that rotates a rotary shaft to drive the compressor main body; and a control unit that controls a drive of the motor. In a case where a value of a voltage to be supplied to the motor is lower than a first voltage value, the control unit detects a stop time of the compressor and changes an operation stop pressure which is a pressure to stop the drive of the motor, based on the stop time.

A control method of an intelligent sterility test pump, a sterilization method and its application. The control method includes monitoring the real-time current of a DC drive motor through a current detection module, to adjust the rotating linear velocity of a peristaltic pump head in real time; when the peristaltic pump head is in a state of pushing a liquid to be tested, reducing the rotating linear velocity of the peristaltic pump head; and when the peristaltic pump head is in an idling state, increasing the rotating linear velocity of the peristaltic pump head. A sterilization method includes the control method of the intelligent sterility test pump. Application of the sterilization method in preparation or detection of foods and medicines.

The present invention relates to a speed control system for hermetic compressors of the variable speed type, which uses a PMSM motor, containing a strategy for optimization, or minimization, of the electric current. Once the minimum current has been defined to meet a given demand for torque, it is applied to the hermetic compressor motor, which will operate at the maximum efficiency point for each load point.

A multi-winding-motor driving system includes a motor and a power unit. The motor has multi-branch windings independent from each other. The power unit includes a rectifier unit and a plurality of inverter units, wherein the inverter units correspond to the multi-branch windings of the motor one to one, and each of the inverter units supplies power to corresponding one branch of the multi-branch windings of the motor.

A pump having an electric motor (14) and an electronic monitoring circuit (30) arranged in a housing part (26) of the motor, for monitoring and recording operating parameters of the pump, one of the operating parameters being the current consumption of the pump, the monitoring circuit (30) having a digital current and voltage measuring circuit (34) which is integrated in a semiconductor component and has at least one Hall sensor (36) for measuring current.

There is provided a wobble plate piston water pump including: a pump body defining a plurality of channels; a rotatable wobble plate disposed in the pump body; a plurality of pistons each located in a respective one of the plurality of channels, the pistons being reciprocatable within the channel along a piston axis; a water passage defined by a water inlet and a water outlet; and a plurality of inlet check valves, each associated with one of the channels, and positioned between the water inlet and the associated channel, the inlet check valves reciprocate along an axis parallel to the piston axis to transition between closed states and open states.

There is provided a wobble plate piston water pump for use in a pressure washer and driven by a driving source, the water pump includes a pump body, a wobble plate, four or more pistons and a water passage defined by a water inlet and a water outlet. The driving source being electric powered and having a power consumption of less than or equal to a 15 ampere draw at 120 volts or 220 volts or the driving source being gas powered and having an engine displacement of less than or equal to 250 cubic centimetres.