Abstract: A method of operating an electrical submersible pumping system that includes realtime monitoring of the wellbore fluid and adjusting pump speed so the fluid entering the pump remains subcooled. The method can include adding sensors within the wellbore and digitally storing fluid data accessible by a pump controller. The pump speed can be increased or decreased by adjusting the frequency of the electrical power delivered to the pump motor.

Abstract: To provide a multistage compressor including an injection circuit, which can continue high-efficiency and high-capacity operations even if the injection circuit is turned on/off in accordance with operating conditions. A multistage compressor includes a high stage side compressing mechanism suctioning the intermediate pressure refrigerant gas compressed with a low stage side compressing mechanism to perform two-stage compression, and an injection circuit for injecting an intermediate pressure refrigerant into the intermediate pressure refrigerant gas suctioned to the high stage side compressing mechanism, the high stage side compressing mechanism including a capacity control mechanism for bypassing a refrigerant gas that is being compressed to a suction side, the injection circuit including an on/off mechanism for performing on/off control of refrigerant injection, and the capacity control mechanism and the on/off mechanism being operated in conjunction with each other.

Abstract: An automatic deactivation mechanism is configured for an air bladder pump having a casing and a motor located therein to pump air into an air bladder from the atmosphere and through an air valve connected through the casing. The automatic deactivation mechanism includes a housing positioned within the casing and has defined therethrough a first aperture in fluid communication with the atmosphere through the casing and a second aperture in fluid communication with the air bladder through the casing. Included within the housing are at least two switches and a diaphragm positioned between the switches. The housing is sealed so that when a threshold pressure is reached therein, at least one switch is triggered by deflection of the diaphragm to automatically deactivate the pump by de-energizing the motor.

Abstract: A method and apparatus for conditioning polishing pads that utilizes an apertured conditioning disk for introducing operation-specific slurries, without the need for additional tooling, platens, and materials handling. The method and apparatus utilizes a vacuum capability to pull waste material out of the polishing pad and through the apertured conditioning disk to evacuate the apparatus through an outlet port. The apparatus also includes a force adjustment system for providing measurement and control of the force applied by the conditioning disk to the polishing pad.

Abstract: A method and apparatus are provided for controlling the operation of a pump in a pumping system, featuring sensing a no water or dead head condition of the flow of a medium in the pumping system operating at a set point pressure; and dynamically reducing the set-point pressure to a lower set point pressure that allows for the flow of the medium to continue at the lower set point pressure while further monitoring the flow of the medium through the pump to protect the pump against damage due to the no water or dead head condition.

Abstract: A method for controlling the motor of an air handling system to provide a desired output of flowing air therefrom while minimizing the power used by the motor, including operationally connecting a switched reluctance electric motor to a blower, operationally connecting an electronic controller to the switched reluctance electric motor, operationally connected at least one sensor to the electronic controller, measuring at least one environmental parameter with the at least one sensor, inputting the desired air flow into the electronic controller, calculating the minimum motor speed necessary to provide the desired air flow, and sending a control signal from the electronic controller to the motor to control the motor to the minimum motor speed necessary to provide the desired air flow.

Abstract: A by-pass control system for a meat injection system has a variable speed pump that transports fluid to a meat injection machine. Excess fluid is transported to a by-pass control valve. The valve has a moveable piston disposed therein that separates the valve into a fluid chamber and an air chamber. The piston moves back and forth based on the relationship between fluid pressure and air pressure. Sensors are disposed within or through the lid or the valve to sense the position of the piston. A controller is connected to the sensors and the variable speed pump and adjusts the speed of the pump based on the position of the piston.

Abstract: A pump and alarm control promotes water safety and prevents entrapment in swimming pools, spas, and water features, such as fountains and waterfalls. The pump and alarm control monitors the vacuum on the influent side of a pump for the pool, spa and/or water feature and a two speed pump for a spa and automatically detects blockages in the pool, spa and/or water feature drains. The pump and alarm control is capable of detecting entrapment and blockages in different and distinct normal pressure operating conditions. Upon detecting a blockage the pump and alarm control shuts down pump operations and activates audible and visual alarms.

Abstract: An intelligent controller (68), adapted for regulating operation of either a refrigeration system or an air conditioning system (20), receives an output electrical signal produced by a pressure sensor (72, 74, 76, 78) included in the system (20). Responsive to the received electrical signal, the intelligent controller (68) energizes operation of a motor (24) that drives a compressor (22) included in the system (20). The programmable electronic circuit (68) performs a calibration operation in which the circuit (68) measures the output electrical signal received from the pressure sensor (72, 74, 76, 78) and stores as an offset the value so measured. The programmable electronic circuit (68) subsequently applies the stored offset for adjusting a value of the output electrical signal received from the pressure sensor (72, 74, 76, 78) during normal operation of the system (20).

Abstract: A method and apparatus for a pump control system. One or more embodiments of the invention include a pump controller that can perform a self-calibrating procedure, can provide precise motor speed control, can provide a limp mode before shutting down the motor when system parameters are exceeded and/or fault conditions occur, can detect fault conditions, and can store fault conditions for later retrieval.

Abstract: One form of a hydrogen operated power system according to this invention is a fuel cell system (20) provided with a supply system which supplies a gaseous fuel from a fuel supply tank (24) to a fuel cell (22), characterized in that a pump (32) is provided in the supply system, which is driven by a sensorless motor (34) having no sensor that detects at least a rotational position of the motor (34).

Abstract: Method for controlling one or more vacuum generators (1) and thereby the vacuum in a vacuum sewage system, in particular controlling one or more liquid ring screw pumps in such system, including beyond the generator/s (1) one or more tubular collectors or suction pipelines (2) connected to the vacuum generator and one or more toilets, urinals, grey water sinks etc (3, 4), connected to the suction pipeline through branch pipelines (6). The rotational speed of the vacuum generator (1) is controlled on the basis of the set vacuum requirement.

Abstract: A compressor system operable to shutdown in response to a shutdown signal. The compressor system includes a compression device operable between a first speed and a second speed to produce a flow of compressed fluid at a pressure. A blowdown valve is movable between a closed position and an open position in which at least a portion of the flow of compressed fluid passes through the blowdown valve to reduce the pressure of the flow of compressed fluid. A sensor is positioned to measure the pressure and a controller is operable to move the blowdown valve to the open position and set the speed of the compression device to a low set point speed in response to the shutdown signal.

Abstract: Systems and methods for monitoring operation of a pump, including verifying operation or actions of a pump, are disclosed. A baseline profile for one or more parameters of a pump may be established. An operating profile may then be created by recording one or more values for the same set of parameters during subsequent operation of the pump. The values of the baseline profile and the operating profile may then be compared at one or more points or sets of points. If the operating profile differs from the baseline profile by more than a certain tolerance an alarm may be sent or another action taken, for example the pumping system may shut down, etc.

Abstract: A method and apparatus for a pump and a pump control system. The apparatus includes pistons integrally formed in a diaphragm and coupled to the diaphragm by convolutes. The convolutes have a bottom surface angled with respect to a top surface of the pistons. The apparatus also includes an outlet port positioned tangentially with respect to the perimeter of an outlet chamber. The apparatus further includes a non-mechanical pressure sensor and a temperature sensor coupled to a pump control system. For the method of the invention, the microcontroller provides a pulse-width modulation control signal to an output power stage in order to selectively control the power provided to the pump. The control signal is based on the pressure within the pump, the current being provided to the pump, the voltage level of the battery, and the temperature of the pump.

Abstract: A water-lifting pump apparatus which is free of a discharge valve and a check valve, is low in cost, and is capable of reducing vibration and noise due to a waterfall after the end of water pumping operation. The water-lifting pump apparatus has a suction tank (10), a discharge tank (20), a pump (30) for pumping water in the suction tank (10) into the discharge tank (20), and a discharge piping (50) connected to a discharge side of the pump, an actuator (60) for actuating the pump (50), a reverse flow preventing mechanism (80) for preventing a reverse flow of water pumped into the discharge tank (20) toward the discharge piping (50), and a back flow rate control (90) for controlling the flow rate of a waterfall falling from the discharge piping (50) into the suction tank (10) when pumping operation is finished.

Abstract: A variable speed pumping system and an associated method for moving water of an aquatic application. The variable speed pumping system includes a water pump for moving water in connection with performance of an operation upon the water. A variable speed motor is operatively connected to drive the pump. A sensor senses a parameter of the operation performed upon the water. A controller controls speed of the motor in response to the sensed parameter of operation.

Abstract: A water pressurizing pump includes a pump mounted in a compartment of a water tank for pressurizing and outputting water. The compartment is sealed by a cover having a first channel in communication between the compartment and a water supply coupler and a second channel having an end in communication with the first channel. A pressure tank is mounted to the other end of the second channel of the cover. A differential pressure valve unit is slideably mounted in the pressure tank adjacent to the second channel. The differential pressure valve unit is movable by the high water pressure in the second channel to allow water from the second channel to enter the pressure tank.

Abstract: A method and apparatus for determining a fluid level and/or output flow during operation of a centrifugal pump, are provided, which may be used for production of gas and/or oil from a well, and include a vector feedback model to derive values of torque and speed from signals indicative of instantaneous current and voltage drawn by the pump motor, a pump model which derives values of the fluid flow rate and the head pressure for the pump from torque and speed inputs, a pumping system model that derives, from the estimated values of the pump operating parameters, an estimated value of fluid level and other pumping system parameters. Controllers responsive to the estimated values of the pumping system parameters control the pump to maintain fluid level at the pump input, near an optimum level, or within a safe operating range and/or output flow from the pump.

Abstract: Embodiments of the present invention are related to a pumping system that accurately dispenses fluid using a multiple stage (“multi-stage”) pump. More particularly, embodiments of the present invention provide for control of a feed stage pump to regulate fluid pressure at a downstream dispense stage pump. According to one embodiment of the present invention, a pressure sensor at the dispense stage pump determines the pressure in a dispense chamber. When the pressure reaches a predefined threshold, the dispense stage pump can begin to increase the available volume of the dispense chamber, thereby causing the pressure in the dispense chamber to drop. As the pressure decreases/increases at the downstream pump, the pressure applied by the upstream pump can bed increased/decreased.

Abstract: A pressure sensing device for an electronic device includes a pressure sensing unit, a control unit, and an alarm unit. The pressure sensing unit is installed in the electronic device, and used for detecting fluid pressure to generate a pressure signal. The control unit is coupled to the pressure sensing unit, and used for determining variation in the fluid pressure in the electronic device according to the pressure signal and generating a control signal. The alarm unit is coupled to the control unit, and used for outputting an alarm signal according to the control signal to execute an alarm function.

Abstract: A metering pump incorporates a method of relating inner loop current to a pump output pressure. Pump/motor speed, which correlates to current, is measured and controlled by a system controller. System temperature is also measured by the system controller. The controller monitors the measured system temperature and provides for compensation for system losses, including inductive-resistive (IR) losses, and for density and viscosity shifts, within a pre-determined allowable system temperature operating range. An initial system calibration is conducted using a “shut-off” test, where the metering pump is run at a very slow known speed while the system is shut-off. After initial start-up, a health-monitoring feature continues to monitor the current as an indicator of pump performance and continuously adjusts a motor speed to maintain a desired level of pump performance.

Abstract: A fluid transporting device is provided with a pump chamber that has a pump function for sucking and discharging a fluid, and is filled therein with the fluid, a casing unit which forms one portion of a wall surface of the pump chamber, a diaphragm which is formed by a conductive polymer film that is subjected to electrochemomechanical expansion and contraction, and forms one portion of the wall surface of the pump chamber, an electrolyte chamber that contains an electrolyte therein, with one portion of the electrolyte being made in contact with the diaphragm, a power supply that applies a voltage to the diaphragm, and a pressure maintaining unit that maintains a pressure of the diaphragm within a predetermined range by moving or deforming the one portion of the wall surface of the electrolyte chamber.

Abstract: An adjustable frequency pump control system (10) that is primarily designed for use in commercial pool filtration systems. The system (10) automatically selects one of three operating speeds that control the speed of a motor that operates a circulation pump (62). The system (10) includes a programmed logic control (PLC) (42) that is activated upon the application of select mode signal (31), a mode timing signal (35), a line pressure signal (37), a circulation pump-run signal (39) and a backwash signal (41). The output of the PLC (42) is a frequency set signal (17) that is applied to an adjustable frequency drive (AFD) (18). From the output of the AFD (18) a motor speed control signal is produced that is applied to the motor that operates the circulation pump (62). The speed of the circulation pump (12) is governed by the frequency of the motor speed control signal, wherein the frequency is determined by the motor speed that is applicable to a particular design point of the pump's filtration cycle.

Abstract: A motor/pump assembly for a motor vehicle brake system including a pump and a motor driving the pump, the pump having opposite working diaphragms which are, in each case, mounted between a pump casing and a cover and thereby delimit a space and which can be moved by a crank drive, the space being assigned, in each case, an inlet duct with an inlet valve and an outlet duct with an outlet valve. The outlet ducts are arranged in the covers and in the pump casing such that air displaced out of the spaces is conducted into an inner space surrounding the crank drive of the pump casing and that an air outlet unit be provided, which allows a low-noise blow-out of the air from the inner space as a result of the deflection of the air.

Abstract: Device for adjusting the operating pressure of an oil-injected compressor installation with a compressor element (2) driven by a motor (4) with an adjustable rotational speed and a control module (13), whereby the device (15) is provided with a controlled inlet valve (16) which is connected to the air inlet (5) and a blow-off mechanism (17) which can be closed by means of a blow-off valve (19), wherein the inlet valve (16), the blow-off valve (19) and the control module (13) are electrically controllable components which are connected to an electronic control unit (22) for adjusting the operating pressure (Pw), which is measured by an operating pressure sensor (23).

Abstract: A pump control system which detects a fluid condition in a pump is disclosed. The pump control system may include a control event based on the fluid condition in the pump. The pump control system may detect a fluid condition in the pump by monitoring the frequency response of the pump.

Abstract: An air-compressing apparatus has four compressors individually supplying compressed air to a tank having a pressure sensor. The pressure sensor is connected to control circuits of the compressors. The control circuits compute times needed for the tank pressure to reach minimum and maximum pressures, respectively, of the tank by using the detected tank pressure and also using a tank pressure change value. The computed time values correspond to the consumption of compressed air. Thus, the control circuits can control the number of compressors to be operated according to the consumption of compressed air.

Abstract: A charging system used for supplying compressed air to a destination includes a compressor for generating the compressed air and a reservoir capable of being alternately discharged and recharged with the compressed air. A supply line fluidly connects the compressor, the reservoir, and the destination. A control valve positioned along the supply line is used in controlling flow of the compressed air from the charging system to the destination. A first branch line and a second branch line are positioned between the reservoir and the supply line. A check valve is positioned along the first branch line that when opened allows the compressed air to flow out of the reservoir into the supply line and when closed prohibits the compressed air from flowing into or out of the reservoir. A pressure protection valve is positioned along the second branch that opens to allow the compressed air to flow into the reservoir when the pressure in the supply line is above a threshold pressure.

Abstract: A rotary compressor includes a compression mechanism, an electric motor and a controller. The compression mechanism includes a piston and a cylinder having two cylinder chambers. The electric motor is configured to change volumes of the cylinder chambers by eccentrically moving the cylinder and the piston relative to each other. The controller is configured to change an output torque of the electric motor in accordance with a variation in a load torque of the compression mechanism in one turn of rotation.

Abstract: An air compressor includes: a tank portion for reserving compressed air used in a pneumatic tool; a compressed air generation portion for generating compressed air and supplying the compressed air to the tank portion; a drive portion including a motor for driving the compressed air generation portion; a control circuit portion for controlling the drive portion; and a pressure sensor for detecting pressure of the compressed air reserved in the tank portion. The control circuit portion includes a unit for controlling the rotational speed of the motor multistageously on the basis of a detection signal output from the pressure sensor.

Abstract: A vacuum control system allows the degree of vacuum in a vacuum vessel to be kept constant while removing vaporized components degassed into the vacuum vessel through a gas permeation diaphragm by stably introducing a very small amount of air into a vacuum exhaust path of the vacuum vessel. The vacuum control system controls the rotary power of a DC brushless motor, continuously controls displacement of a vacuum pump, and thus keeps the degree of vacuum in a vacuum vessel constant, by decompressing the inside of the vacuum vessel using an exhaust vacuum pump which operates with the DC brushless motor, monitoring the inside pressure of the vacuum vessel using a pressure sensor, and controlling a voltage applied to the DC brushless motor on the basis of an output signal resulting from measurement of the inside pressure of the vacuum vessel by the pressure sensor.

Abstract: A supply flow path for supplying a solvent is described. The supply flow path includes metering devices each with a piston, the metering devices being adapted for metering the solvent through separate source paths feeding the supply flow path. The supply flow path further includes a control unit adapted for controlling the metering devices' piston movement in accordance with solvent pressure, wherein a variation of the solvent pressure gives rise to a corresponding variation of a solvent volume contained in the supply flow path or a part thereof. The control unit is adapted for compensating for the variation of the solvent volume by corresponding movements or forward or backward displacements of the pistons.

Abstract: A pumping system for evacuating an enclosure comprises a pumping mechanism (30), a motor (32) for driving the pumping mechanism, and a controller (36) for controlling the motor. The controller sets a maximum value for a rotational frequency of the motor and a maximum value for a current in the motor, and, to optimise the performance of the pumping system, independently adjusts the maximum values during evacuation of the enclosure.

Abstract: A fluid displacement apparatus includes a housing for receiving a refrigerant, a driving shaft rotatably received in the housing, a magnetic clutch attached to the driving shaft for rotation transmitting purposes, a fixed scroll disposed in the housing, an orbiting scroll rotatably received and engaged in the housing and interfitting with the fixed scroll for compressing the refrigerant and for generating a pressurized refrigerant, the housing includes a compartment communicating with the inner chamber of the housing with a passage for receiving a pressure sensing device which may sense the pressure of the pressurized refrigerant for detecting whether the refrigerant in the housing is over pressure or not.

Abstract: A method and apparatus are provided for estimating and/or precluding stick-slip, or other oscillatory or resonant behavior, through use of a virtual transducer, which precludes the need for having sensors located adjacent to a driven element of the system, or adjacent contact surfaces at which the stick-slip relative motion may occur. Parameters measurable at a drive mechanism are utilized for controlling a system in a manner which precludes stick-slip, or other oscillatory or resonant behavior, of the driven element. Relative motion between contacting surfaces in the driven element, prone to stick-slip behavior, is controlled such that, after sufficient force is applied by the drive element to overcome static friction forces between the contacting surfaces and break them free from one another, relative motion between the surfaces is maintained at a high enough relative speed that the surfaces are precluded from statically contacting one another, so that stick-slip behavior is precluded.

Abstract: For a motor that drives a compressed air generator, three operating modes which includes a powerful mode for rotating a motor in a high speed range, a silent mode for rotating the motor in a low speed range, and an automatic mode for automatically changing the rotation speed of the motor from the low speed to the high speed in accordance with a setup condition are prepared. A user can designate a desired operating mode by using an operating mode selection switch.

Abstract: A digital pressure controller that utilizes a microprocessor provides for control of the speed of a fluid pump engine for the purpose of maintaining specified pressures at both the inlet and outlet of the pump. Based upon pressure sensor output, and computations based on multiple calibrations between pump speed and pressure, and between output voltage and pump speed, a pump drive mechanism speed is determined by the control logic of the microprocessor, which speed maintains at least one of the inlet and outlet pressures within a specified range. The microprocessor may determine the specific weight of the fluid being pumped in order to select the pump drive mechanism speed.

Abstract: An electric actuator of the present invention includes a hydraulic fluid supply device and an actuator actuated in response to an input of hydraulic fluid from a variable-volume pump. The hydraulic fluid supply device includes an adjustable-speed motor, the variable-volume pump which is driven by the adjustable-speed motor and ejects hydraulic fluid, an electric motor control unit which controls the adjustable-speed motor so as to achieve an intended rotation speed, and a pump control unit which controls the variable-volume pump so that the ejection volume of the variable-volume pump decreases with an increase in the ejection pressure of the variable-volume pump.

Abstract: This cabinet comprises an enclosure for horizontally storing unopened bottles, and electric means for refrigerating the internal volume of this enclosure. To make it easier to keep opened bottles in the cabinet, while increasing the keeping quality of these opened bottles, the cabinet comprises stoppers for aspirating opened bottles arranged vertically in the internal volume of the enclosure. These vacuum stoppers are incorporated so as to be freely movable inside the enclosure and each delimit an aspiration passageway which emerges in a sealed manner in the neck of the opened bottle and which is connected to an electric vacuum pump via a flexible circuit. In addition, this pump is controlled by a manual on/off switch, supported by the vacuum stopper, so as to be activated when the air pressure in the vacuum stopper is greater than a predetermined value, for example equal to approximately 300 millibars below atmospheric pressure.

Abstract: A pump driving apparatus has a characteristic changing section which receives a set pressure, a set flowing amount, a set horse power, and a DC voltage of the converter section as input, outputs modified values of pressure, flowing amount, and horse power, and supplies the modified values to the horse power command generation section. Therefore, the motor can be driven to suit the change in power voltage so that the motor capacity can be utilized sufficiently.

Abstract: An arrangement (10) for controlling the liquid level in a basin (60) by selectively actuating a pump (64) has an environmentally-sealed enclosure (22) with an internal volume subject to thermal and pressure effects. A first (14) and a second (16) pressure sensing means are positioned in the enclosure and a barrier fluid (18) fills a balance of the internal volume. The first sensing means (14) is in a first chamber (22a) of the enclosure (22) and the second sensing means (16) is in a second chamber (22b). The barrier fluid (18) has a first portion (18a) in the first chamber (22a) and a second portion in the second chamber (22b). The first pressure sensing means (14) communicates an “on/off” signal to the pump (64). Diaphragms (26, 40) in the respective chambers (22a, 22b) allow the device to adjust to changes in atmospheric pressures. The barrier fluid (18) is electrically non-conductive, chemically non-reactive with any materials comprising the pressure sensing means and, preferably, an oil.

Abstract: Disclosed herein is a stable solvent delivery device capable of delivering solvent both at high pressure and at constant flow rate. A solvent delivery device comprises a plurality of plungers which reciprocate in the respective pump chambers including an eluent charge side pump chamber and an eluent discharge side pump chamber, a motor to reciprocate these plungers, a control unit to control the operation of the motor, valves which are respectively set at the eluent inlet and outlet of the eluent charge side pump chamber, a first sensor to measure the quantity of load received by the plunger in the eluent charge side pump chamber, and a second sensor to measure the pressure of the eluent discharged from the eluent discharge side pump chamber.

Abstract: When an air pump is operated, a brush temperature increase rate stored in an ECU in relation to a discharge pressure of the air pump and a brush temperature is multiplied by a calculation cycle time, and the resultant value is cumulatively added. When the air pump is stopped, a brush temperature decrease rate stored in the ECU in relation to the brush temperature is multiplied by the calculation cycle time, and the resultant value is cumulatively added. Each of the cumulative values read from a map is added to and subtracted from an initial brush temperature value, respectively so as to estimate the brush temperature.

Abstract: A control device is provided for use with a pneumatic pump for generating output pressure, a pressure sensor for indicating the level of the output pressure, and an input device for receiving a target pressure level input by a user. The control device is configured to monitor the sensed output pressure during a pressurizing condition in which the pump provides increasing output pressure. The control device is further configured to maintain the pressurizing condition while the level of the sensed output pressure increases past the target pressure level, and to terminate the pressurizing condition in response to the sensed output pressure increasing to a level that exceeds the target pressure level by a predetermined differential value.

Abstract: A control switch incorporates a solid state transducer, a strain gauge. The transducer responds to a local environmental condition, such as fluid level, or pressure and exhibits a parameter change which can be detected as an electrical output. Control circuits coupled to the transducer can sense the parameter change and switch a source of electrical energy to a load in response thereto.

Abstract: A cabin pressure control system (CPCS) software control logic modification may boost the voltage applied to a motor by applying a duty cycle offset to compensate for asymmetric motor loading. The motor may be part of an open-loop system for operating a butterfly valve that may regulate outflow from the aircraft cabin. In CPCS applications, the loading on the butterfly valve is unidirectional due to a mechanical spring and pneumatic loading, thus, causing asymmetric loading to the motor. By boosting the motor voltage when the motor is required to act against the asymmetric load, CPCS performance and robustness may be improved.

Abstract: An oil pressure unit includes an inverter arranged to supply electric power to a motor; a load sensor arranged to detect a load of the oil pressure pump; a rotation sensor arranged to detect a rotation speed of the motor; a current command value calculation part configured to calculate a current command value so that a deviation between a speed command value representing a target rotation speed of the motor and a rotation speed of the motor converges to zero; a correction part configured to correct the current command value based on the load of the oil pressure pump; and a control signal generation part configured to output a control signal to the inverter based on a corrected current command value.

Abstract: An infusion device comprises a pusher for a plunger of a syringe containing a liquid to be infused. A load cell measures the push force. An encoder associated to a motor commanding the pusher measures the displacement of the pusher. A controller signals an alarm when the ratio between the variation of the push force and the displacement exceeds a predetermined threshold. The device, which serves for infusing an anticoagulant into an extracorporeal blood circuit in a dialysis apparatus, is able to signal an onset of an anomalous situation of lack of infusion in good time.

Abstract: As one example, a method of operating a fuel delivery system of a directly injected internal combustion engine including a plurality of in-cylinder direct fuel injectors, a higher pressure fuel pump and a lower pressure fuel pump is provided. The method comprises operating the lower pressure fuel pump and the higher pressure fuel pump to maintain a prescribed fuel pressure at the fuel injectors; and varying an amount of pump work that is provided by the lower pressure fuel pump relative to the higher pressure fuel pump responsive to an indication of the efficiency of the higher pressure pump.