Abstract: A pump system generally comprising an electrical connector operable to couple with an electric circuit to receive electricity, an electric motor operable to actuate a pump to pump a fluid, and a variable frequency drive (VFD) controller. The VFD controller is operable to control the rotational speed of the electric motor by providing a variable frequency signal to the electric motor to prevent the current utilized by the electric motor from exceeding a maximum current level associated with the electric circuit.

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 sump draining apparatus having a pressure transducer engaged in a receptacle that is in turn engaged in an open-ended collar of a housing. The receptacle and thus the pressure transducer is slideable in the axial direction into and out of the open-ended collar. The housing is generally cylindrical and contains a pump and motor, each of which has a generally cylindrical shape and is axially stacked in the housing. A cord having a vent and electrical leads for the pressure transducer is releasably engaged via a cord restraint at one end portion of the housing and the pressure transducer is releasably engaged in the receptacle in the open-ended collar at the other end of the housing. The receptacle and sensor may be removed, serviced, and/or replaced without the housing being opened and without the pump and motor being removed.

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 pump controller and pump controlling method for dispensing a precise amount of low viscosity fluid are provided in which the problems of double dispenses and stuttered dispenses are avoided. In particular, the timing of the valves and motors in the pumping apparatus are adjusted to avoid these problems.

Abstract: A control circuit portion in an air compressor finds the rate of decrease of pressure inside a tank portion when a motor is at rest relative to the time based on a detection signal from a pressure sensor. Where the rate of decrease of pressure is greater than a given value, the motor is started without waiting for the pressure inside the tank to decrease to a motor restart pressure value, the pressure inside the tank portion rises to a given motor stop pressure value and the motor is then controlled to come to a stop. Where the rate of decrease of pressure is less than the given value, the motor is started when the pressure inside the tank has decreased to the motor restart pressure value. After the start of the motor, the motor is controlled such that it comes to a stop when the pressure inside the tank portion increases to a given value lower than the motor stop pressure value.

Abstract: A linear compressor control system includes an electronic circuit controlling an electric motor that drive a piston of the compressor, such that the motor is operated intermittently with an on-time (tL) and an off-time (tD) to keep the compression capacity of the compressor substantially constant. The compressor is associated with a closed cooling circuit having an evaporator and a condenser. The off-time (tD) is shorter than the time necessary for the evaporation pressure (PE) in the evaporator and the condensation pressure (Pc) in the condenser to equalize each other after the compressor has been turned off.

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: When the shift position is changed to the drive position, the amount of oil that is supplied to an automatic shift unit is increased by a larger amount as the standby hydraulic pressure is lower. Therefore, even if the standby hydraulic pressure is decreased, the required hydraulic pressure is more easily achieved when the shift position is changed to the drive position. Therefore, it is possible to decrease the standby hydraulic pressure without slowing down the response to the automatic shift unit to the hydraulic pressure and reducing the useful life of the automatic shift unit. Thus, the amount of electricity consumed by the electric oil pump is reduced. As a result, it is possible to enhance the fuel efficiency.

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 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 first pump of small capacity and a second pump of large capacity are connected directly with each other and are driven by a variable-speed motor. The rotational speed of the variable-speed motor is controlled by a control device. In a first mode, a first discharge line of the first pump and a second discharge line of the second pump are disconnected with each other, making the first pump unloaded. With the first pump in the unloaded state, a constant-horsepower operation is performed, where the discharge fluid is brought into a high pressure by relatively small torque. In a second mode, the first discharge line and the second discharge line are connected with each other by a switching valve. With the first and second discharge lines in the connected state, a constant-horsepower operation is performed, where a high flow rate of discharge fluid is discharged at relatively low rotational speed.

Abstract: A pressure sensor subsystem measures the pressure within a fuel pump and outputs an under-pressure signal when the measured pressure is below a predetermined threshold pressure value. A temperature sensor subsystem measures the temperature within the fuel pump and outputs an over-temperature signal when the measured temperature is above a predetermined threshold temperature value. A timing circuit monitors the pressure sensor subsystem and the temperature sensor subsystem for output of the under-pressure and over-temperature signals and outputs a pump disconnect signal when at least one of the signals is output for a prescribed time duration. A power controller disengages power from the pump upon output of a pump disconnect signal by the timing circuit.

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 device for supplying pressure to an actuation unit of a vehicle brake system, in particular to a vehicle brake system of the ‘brake-by-wire’ type, comprising a pneumatic motor-and-pump assembly with a pump and a motor driving the pump, wherein the motor-and-pump assembly is controlled by an electronic control unit depending on a pressure level or pressure difference in a pneumatic brake booster of the actuation unit, with the pressure level in a chamber or a difference in pressure between two chambers of the brake booster being detected by means of a sensor. In order to maintain the availability of the service brake function as high as possible and to obtain a maximum possible redundancy, the control unit, used to control the motor-and-pump assembly comprises a logic module and a power module, which are arranged separately of each other.

Abstract: A vacuum tank assembly is provided for use on an RV or a boat and includes a two-piece vacuum tank. The two-piece vacuum tank includes a body and a removable top with a gasket located between the body and removable top. A dip tube is integrated into the removable top, thus, forming an opening in the removable top and thereby reducing maintenance problems associated with mechanically attached dip tube assemblies. A vacuum pump is provided to pump the waste out of the vacuum tank into a holding tank.

Abstract: A vacuum pump includes at least two stages (2, 3), a motor (8) for driving pump-active elements of the two stages (2, 3), a transmission unit (7) for transmitting driving power from the motor (8) to the pump-active elements, a motor control (9) for controlling a rotational speed of the motor (8), and an evaluation unit (12) electrically connectable with pressure-sensitive signal sensor (10) located between the two stages for receiving a signal generated by the signal sensor and connected with the motor control (9) for transmitting an evaluated signal thereto, so that the motor control (9) can change a rotational speed of the motor (8) in accordance with the received evaluated signal.

Abstract: A pumping apparatus for a jetted-fluid system includes a pump having an inlet connectable to the drain, and an outlet connectable to the return. The pump is adapted to receive the fluid from the drain and jet fluid through the return. The apparatus includes a motor coupled to the pump to operate the pump, a sensor configured to generate a signal having a relation to a parameter of the motor, and a switch coupled to the motor and configured to control at least a characteristic of the motor. The apparatus also includes a microcontroller coupled to the sensor and the switch. The microcontroller includes a model observer configured to receive a first value based on the signal and to generate a second value representative of at least one of a modeled flow or a modeled pressure based on the first value. The microcontroller is configured to control the motor based on the second value.

Abstract: A system and method is disclosed for controlling the input electrical current to an infusion pump stepper motor based on predetermined torque requirements. The system can include a motor controller and a non-volatile memory containing expected load torque values throughout a pump cycle. Responsive to the expected load torque values, the motor controller provides the stepper motor with a varying electrical current for overcoming load torque at each point in the pumping cycle. Additional factors can also be considered for varying the electrical current. These factors include, but are not limited to, temperature, pressure, and elapsed operating time.

Abstract: The apparatus comprises a displacement pump with at least one flow vessel, with a pump drive, and with a support means for holding the flow vessel. Furthermore, the apparatus comprises a measuring arrangement responsive to the displacement motions performed by the flow vessel, wherein the displacement motions are picked up by a pressure sensor diposed at the flow vessel or by a strain sensor disposed at the support means. The measuring arrangement serves to sense an actual displacement motion of the flow vessel robustly and reliably, and to deliver a measurement signal representative of this motion. The signal is particularly suited for generating a flow rate estimate representative of the instantaneous volume flow rate and/or for generating a status signal signaling a current operational status. Further, a method is disclosed which supplies information serving to monitor such an apparatus. The apparatus is suitable for using in a sampler.

Abstract: An air compressor comprises a tank portion for reserving a compressed air, a compressed air generating portion for generating the compressed air to be supplied to the tank portion, a motor for driving the compressed air generating portion, and a pressure switch mechanism having a pressure sensor in a part of the tank portion, and controlling the motor to be turned on or off in accordance with an output of the pressure sensor, characterized in that when the time change rate of the pressure within air tank is greater than a predetermined value, the motor is restarted without waiting until the pressure decreases to the switch on point at the time of pressure fall.

Abstract: A system for controlling air flow comprises an inlet, a first compressor, a first pressure sensor, a second pressure sensor, a first temperature sensor, and a first controller. The inlet is configured to direct a first stream of air into the system. The first compressor is configured to pull in the first stream of air through the inlet and compress the first stream of air. The first pressure sensor senses a first pressure of the first stream of air prior to compression in the first compressor, the second pressure sensor senses a second pressure of the first stream of air after compression in the first compressor, and the first temperature sensor senses a temperature of the first stream of air after compression in the first compressor. The controller adjusts a speed of the first compressor based upon a comparison between a desired flow rate and a calculated flow rate.

Abstract: The invention relates to quantitative dosing of small amounts of liquids having a volume of microliter or nanoliter order. Such a dosing technique is useful for instance for productive serial dosing in applications of clinical chemistry. In dosing device of the invention, flexible bellows (5) attached to a body (1) define a liquid space (15) filled with a liquid to be dosed and communicate with a dosing tip (19). The bellows (5) are provided with an actuator (7) for operation thereof, constricting the liquid space to cause a liquid dose to be discharged from the dosing tip. The invention is further directed to a dosing method based on movements of bellows moved by a magnetic actuator, and to a method wherein liquid is dosed as individual small droplets from the dosing tip by first accelerating and then by slowing down the motion of the bellows by means of the actuator.

Abstract: A compressed air system and method of operating the system wherein the slip between the compressor motor and its powering alternator is used as an indication of whether the compressor is running in a loaded or unloaded mode. A slip parameter such as % Slip is determined and compared to an allowable value in real time. If the compressor is determined to be erroneously in a loaded mode, a corrective action may be taken to reduce the probability that the motor is later started with the compressor still in the loaded mode.

Abstract: A system for maintaining at least one air characteristic in an air ventilated facility using at least one fan filter unit, the system comprising at least one sensor for sensing the at least one air characteristic, the at least one sensor being exposed to the air ventilated facility; the at least one sensor being operatively connected to a control system that is operatively connected to the at least one fan filter unit; the control system receiving output readings from the at least one sensor and determining if the output reading is within a range and, in response to a negative determination, providing a command to the at least one fan filter unit to adjust the at least one fan filter unit operating speed. A corresponding method and apparatus are also disclosed.

Abstract: A method and arrangement for soft start up of a pump system, that includes a pump (401) for generating a liquid flow, an electrical drive (402, 403, 404) disposed to actuate the pump, and a pressure sensor (408) disposed to measure a liquid pressure at a flow output of the pump. The objectives of the invention are achieved with a solution in which a rate of change of rotation speed of the pump during a start up phase is made to be dependent on a rate of change of measured liquid pressure speed is a descending function of the rate of change of the measured liquid pressure.

Abstract: A peristaltic pump tubing system for use with a peristaltic pump roller assembly in a surgical procedure. The system comprises a uniquely shaped disposable cassette for retaining tubing to be used during the procedure and a uniquely shaped cassette receiving station situated adjacent the roller assembly. The cassette comprises a frame for holding the tube in a loop shape for engagement with the peristaltic rollers. The frame supports a one-sided pressure transducer to indicate the pressure within the tube. The cassette receiving station includes a sensor for engaging the one-sided pressure transducer and is situated adjacent the rollers of the peristaltic pump on the pump housing. A retaining bracket cooperates with the inherent resiliency of the tubing loop to hold the tubing in place against the rollers.

Abstract: A portable air/gas compressor capable of manufacturing compressed or pressurized air/gas. In at least one embodiment, compressors capable of producing clean, dry, compressed air/gas (e.g., either in naturally occurring atmospheric nitrogen/oxygen ratios or as purified nitrogen or in alternative ratios therebetween) employing atmospheric air as a starting material. In at least one additional embodiment, compressors which are compact, lightweight, portable and/or mechanically non-complex.

Abstract: A pump apparatus includes a housing. A rotor is eccentrically accommodated in the housing. A motor rotates the rotor in the housing. A vane is substantially radially movable relative to the rotor. The vane has a radially outer end that is slidable relative to an inner circumferential periphery of the housing as the rotor and the vane rotates for increasing or decreasing pressure of gas. A pressure sensor detects pressure of the gas. A control unit that evaluates whether an adherence abnormality, in which the vane adheres to the rotor, occurs in accordance with both a detection signal of the pressure sensor and electricity supplied to the motor when the motor rotates the rotor. When the control unit determines the adherence abnormality to be caused, the control unit operates the motor to remove the vane from the rotor.

Abstract: To economically perform preparatory chromatography, a plurality of pumps each having a corresponding one of a plurality of pistons and a corresponding one of a plurality of cylinders are driven by one motor to draw and pump solvent simultaneously into corresponding columns. To form a gradient, the pumps are connected to two-way valves that are connected alternately to a first solvent and a second solvent, whereby the time said valve is in a first position controls the amount of solvent drawn from the first reservoir into said pumps and the amount of time in said second position controls the amount of said second solvent drawn from the second reservoir into said pumps and the solvent is mixed in the pumping systems. The detectors are photodiodes mounted to light guides in the flow cells that generate signals related to light absorbance and communicate with a controller, whereby the controller receives signals indicating solute between the light guides and causes collection of solute.

Abstract: The invention provides a pump for liquid chromatography excellent in feeding liquid stably at an extremely low flow rate and in discharging bubbles at startup. In a pump for liquid chromatography including a cylinder and a plunger that reciprocates in the cylinder to suck and discharge fluid, the pump further includes a large-flow-rate pump that feeds liquid by the plunger, a small-flow-rate pump that feeds the liquid by the plunger, motion conversion means that converts the rotational motion of a motor to a reciprocating motion, an actuator that directly drives the plunger, and a drive part that drives the actuator, and selectively switches means for driving the plunger.

Abstract: An improved air pulse generator produces high frequency chest wall oscillations (HFCWO) and includes means for internal heat dissipation. Internal heat generated by an internal diaphragm motor is dissipated by having a portion of the air chamber associated with the diaphragm motor being comprised of metal, by shaping a support associated with the diaphragm motor to allow increased air circulation around the diaphragm motor and positioning a vent in the housing of the air pulse generator that maximizes the release of heat from the diaphragm motor. Internal heat generated by internal electronic circuitry on a control board is dissipated by a heatsink attached to the control board.

Abstract: A compressed air system, wherein a decision to de-energize a compressor motor is made with consideration of the likely need for the operation of the compressor at a future point in time. A rate of pressure decay in an air reservoir may be extrapolated over a predetermined time period to predict the need for operation of the compressor within the time period. If operation of the compressor is predicted to be needed within the time period, the compressor is allowed to continue to run in an unloaded mode beyond a normal cool down period.

Abstract: The present invention provides a system for controlling speed of the fuel pump. The system includes a fuel pump, a controller, and a field modification module. The fuel pump is configured to receive a driving signal causing the fuel pump to pump fuel. The controller is configured to determine a desired fuel pump speed and generate a control signal based on the desired fuel pump speed. The field modification module is located proximate the fuel pump and is in communication with the controller to receive the control signal. The field modification module generates a flux in response the control signal thereby controlling speed and torque of the fuel pump.

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 method and a system for detecting the speed of a pump motor of a hydraulic pump system are provided, in which pump system a pump is driven by a pump motor to deliver hydraulic fluid into a pump reservoir. In accordance with the present invention, a pressure signal representing the fluid-delivery activity of the pump is detected, and the pressure peaks within this pressure signal identified. The speed of the pump motor is determined on the basis of the frequency or the time intervals of these pressure peaks.

Abstract: A liquid pressuring device comprises a reciprocating pump (1), pressure sensor (23) and pressure control unit (25) which is adapted to control the motion of the plungers (5A, 5B) so as to make an actual delivery pressure value reach a predetermined threshold and, after reaching the threshold, control the actual delivery pressure value so as to determine an optimum feed rate, and thereafter maintain the feed rate of the plungers constant at the optimum feed rate. The pressure control means (25) may include a proportional control element for performing, after the actual delivery pressure value has reached the threshold, the proportional control of the actual delivery pressure value during a time until the plungers (5A, 5B) first reach the forward stroke end thereof.

Abstract: The invention relates to a method for regulating a compressor installation with at least one compressor element (6) driven by a motor and, in the pressure conduit (11) thereof, a dryer (2) of the type comprising a pressure vessel (24) with a drying zone (3) and a regeneration zone (4), and a rotor (25) continuously rotated in this pressure vessel (24) by a motor (33), which rotor is filled with a regenerable drying agent. A portion of the compressed air is supplied, by means of a branch (15), to the regeneration zone (4) and, after cooling down and separation of the condensed water, is fed back to the pressure conduit (11). The speed of both motors (9, 33) is regulated by a regulation device (13) in function of the pressure in the pressure conduit (11).

Abstract: In a pump for feeding a liquid for chromatography, first and second plungers form first and second volumes respectively together with first and second chambers, the first plunger is prevented from changing the first volume sufficiently for feeding the liquid between the first and second volumes when the second plunger decreases the second volume to discharge the fluid from the second volume to an outlet path of the pump for the chromatography.

Abstract: The invention provides a pump which has reduced pressure loss by using fewer mechanical on-off valves, which has increased reliability, which can be used under a high load pressure, which can be driven at a high frequency, and which has good drive efficiency by increasing discharge fluid volume per pumping period. A circular diaphragm, disposed at the bottom portion of a case, has its outer peripheral edge secured to and supported by the case. A piezoelectric device to move the diaphragm is disposed at the bottom surface of the diaphragm. A space between the diaphragm and the top wall of the case is a pump chamber. An inlet flow path, having a check valve serving as a fluid resistor disposed thereat, and an outlet flow path, which opens to the pump chamber during operation of the pump, open towards the pump chamber.

Abstract: The invention provides a pump with high driving efficiency in which the number of mechanical switching valves is decreased to reduce pressure loss and increase reliability, and which is ready for high load pressure and high-frequency driving, and which increases the discharged fluid volume for one cycle of pumping. A circular diaphragm arranged on the bottom of a casing has the outer edge fixed to the casing. The diaphragm includes a piezoelectric element to move the diaphragm on the bottom surface thereof. The space between the diaphragm and the top wall of the casing serves as a pump chamber, wherein a suction channel and a discharge channel are opened to the pump chamber, the suction channel having a check valve serving as a fluid resistive element and the discharge channel being always communicated with the pump chamber, even during the operation of the pump.

Abstract: A pressure maintenance assembly for a domestic water well system. The assembly comprises a pressure maintenance valve having an inlet side and an outlet side, a pressure tank in fluidic communication with the outlet side, and a calibrated bypass. When the valve is closed, the calibrated bypass provides fluidic communication between the inlet side and the outlet side. The size of the calibrated bypass and the pressure tank are adapted and constructed to permit a flow rate between the inlet side and the outlet side that will fill the pressure tank in a time interval less than twice the time required to pump a volume of water that will dissipate heat generated by the pump when it is turned on.

Abstract: Apparatus for driving a three-phase compressor assembly from a single-phase electrical power supply having first and second power lines, said three-phase compressor assembly comprising a compressor having a rotatable shaft, an electrical motor having a rotatable shaft coupled to the rotatable shaft of the compressor, the electrical motor having at least first, second and third motor windings and having at least first, second and third terminals connected to the first, second and third windings, means adapted to connect the first and second power lines of the single-phase power supply to the first and second terminals and a torque augmentation circuit for injecting current into the third terminal and including a capacitor and an electrical component in series with the capacitor, said electrical component having resistive characteristics and having means for essentially interrupting the current being injected into the third terminal.

Abstract: A control system for a variable displacement pump. The control system is operably associated with an engine control unit for passively or actively controlling the output of the pump in response to signals from the engine control unit.

Abstract: A method and apparatus for detecting the occurrence of surge or incipient surge in a centrifugal compressor is supplied. The centrifugal compressor has an inlet passage, an inlet passage wall and an impeller. When flowing a fluid through the centrifugal compressor thereby establishing a fluid flow in the inlet passage, the fluid flow is measured in the inlet passage proximate the inlet passage wall and proximate the impeller. The measurements may include detecting a reverse in the fluid flow direction, measuring a tangential component to the fluid flow, measuring a substantial decrease in the axial fluid flow, and/or measuring the fluid temperature. Fluid flow in the compressor can then be modified or controlled to prevent surge.

Abstract: A method for controlling a motor (11) driving a pump (10) using a microcomputer (14) includes repeatedly sampling a parameter representative of motor torque over one cycle of operation of the pump (10), determining at least one point of maximum motor torque during said one cycle of operation of the pump (FIG. 4); applying speed commands to the motor (11) from a table of stored speed values in memory (19), said values being selected to provide relatively greater speed commands at points of lower motor torque and relatively lesser speed commands at points of higher pump pressure corresponding to higher motor torque, while maintaining at least a base speed command to prevent stalling; and synchronizing the first value in the table of stored values to the point of maximum motor torque.

Abstract: A monitoring system for use in a process plant having a pump or other device capable of undergoing cavitation, uses a characteristic curve, a model and/or process variables, such as indications of a flow rate within the device or a pressure at the input of the device, to detect or predict the occurrence of cavitation within the device. Upon detecting the occurrence of cavitation, the monitoring system may alert a user to the existence of the cavitation, may suggest possible causes of the cavitation and may suggest possible actions to be taken to alleviate the cavitation.

Abstract: A method, system and apparatus for performing peritoneal dialysis are provided. To this end, in part, a method of controlling pressure in a medical fluid pump is provided. The method includes the steps of controlling a pump member acceleration during a first portion of a pump stroke and adaptively changing the pump member velocity during a second portion of the pump stroke.

Abstract: A pressure sensor subsystem measures the pressure within a fuel pump and outputs an under-pressure signal when the measured pressure is below a predetermined threshold pressure value. A temperature sensor subsystem measures the temperature within the fuel pump and outputs an over-temperature signal when the measured temperature is above a predetermined threshold temperature value. A timing circuit monitors the pressure sensor subsystem and the temperature sensor subsystem for output of the under-pressure and over-temperature signals and outputs a pump disconnect signal when at least one of the signals is output for a prescribed time duration. A power controller disengages power from the pump upon output of a pump disconnect signal by the timing circuit.

Abstract: A scroll-type machine is disclosed which is particularly well suited for use as a compressor in refrigeration and air conditioning systems and incorporates a unique arrangement for modulating the capacity thereof. In one group of embodiments the capacity of the scroll-type machine is modulated by relative axial movement between the scroll members so as to form a leakage path across the wrap tips and opposed end plates. In another group of embodiments, modulation is achieved by reducing the orbital radius of one of the scroll members to thereby form a leakage path across the flank surfaces of the wraps. Both types of scroll separation may be accomplished in a time pulsed manner to thereby enable a full range of modulation with the duration of the loading and unloading periods being selected to maximize the efficiency of the overall system.