Abstract: There is disclosed an apparatus and method for detecting cavitation in fluid machines, for example pumps (100). In one embodiment a piezoelectric gasket (102) is used as a sensor to sense cavitation. In some embodiments highpass filters (302), (501) are used to detect ultrasonic acoustic signals in about the MHz range. If the energy in the MHz range is excessive then cavitation is deemed to be occurring and the speed of a motor (110) may be reduced in proportion to the degree of cavitation deemed to be occurring. In another embodiment (FIG. 5) the energy in the MHz range is normalized against the energy in the kHz range. Other sensors (600, 701) are also disclosed.

Abstract: The invention relates to a centrifugal pump assembly with an electric drive motor and with a control device having a frequency converter, for the control of the rotational speed of the drive motor, wherein the control device is designed in a manner such that in at least one control region, a field weakening is produced in the drive motor, by way of which the rotational speed of the drive motor is increased.

Abstract: A method and arrangement for soft start up of a pump system, that includes a pump for generating a liquid flow, an electrical drive disposed to actuate the pump, and a pressure sensor disposed to measure a liquid pressure at a flow output of the pump. The rate of change of rotation speed of the pump during a start up phase is dependent on a rate of change of measured liquid pressure, wherein the rate of change of the rotation speed is a descending function of the rate of change of the measured liquid pressure.

Abstract: A method of controlling fluid flow in a fluid network system by means of a plurality of fluid machines. The disclosure provides a simple empirical method of identifying network characteristics of the fluid network system used for providing the required fluid flow rate in the fluid network system utilizing minimal fluid machine power. The method includes the steps of determining a relation between a change in fluid machine speed and a corresponding change in fluid flow rate for each of the plurality of fluid machines empirically; determining a minimum total fluid machine power which provides a minimum required flow rate in the fluid network system based on a constraint involving the relation between the fluid flow rate and the corresponding fluid machine speed, and controlling a speed of the plurality of fluid machines such that the minimum total fluid machine power in the fluid network system is attained.

Abstract: A micro cooling fan includes a housing, a fan wheel, and a main circuit board. The main circuit board has a stator and a driving circuit. The stator is electrically connected to the driving circuit. The stator is disposed on a first inner surface, and the driving circuit is disposed on a first outer surface, so that the housing and the driving circuit of the micro fan motor form an integral structure. The first outer surface is opposite to the first inner surface, or the first outer surface is located on a side surface of the housing. Therefore, by disposing the driving circuit on the first outer surface, the wind resistance of the fan blades is reduced, and the air volume of the micro cooling fan is increased accordingly, so that the cooling effect of the micro cooling fan is improved.

Abstract: An apparatus and method for controlling a velocity of a cooling fan using a timer and a temperature sensor in a set-top box (STB) are provided. An apparatus for controlling a velocity of a cooling fan in an STB may include a temperature sensor unit to change a resistor to be in inverse proportion to an internal temperature, using a thermistor, a timer unit to generate a pulse signal using a capacitor and the resistor of the temperature sensor unit, a switching unit to turn on/off applied voltage, using the generated pulse signal, and a power source unit to apply the voltage to the switching unit.

Abstract: A scroll compressor is provided. A value obtained by multiplying a wrap height (H) by a driving speed (V) may be controlled to be within a range of approximately 500˜1000 mmHz at a low speed driving (less than approximately 35 Hz). The wrap height of the scroll compressor, and the driving speed may be set to be optimum, thereby preventing the scroll compressor from being operated at a speed excessively lower or higher than a predetermined driving speed. This may allow the scroll compressor to be operated at an optimum low speed corresponding to the wrap height, and thus, the compressor and a refrigerating cycle apparatus having the same may have enhanced performances.

Abstract: Embodiments of the systems and methods disclosed herein utilize a brushless DC motor (BLDCM) to drive a single-stage or a multi-stage pump in a pumping system for real time, smooth motion, and extremely precise and repeatable position control over fluid movements and dispense amounts, useful in semiconductor manufacturing. The BLDCM may employ a position sensor for real time position feedback to a processor executing a custom field-oriented control scheme. Embodiments of the invention can reduce heat generation without undesirably compromising the precise position control of the dispense pump by increasing and decreasing, via a custom control scheme, the operating frequency of the BLDCM according to the criticality of the underlying function(s). The control scheme can run the BLDCM at very low speeds while maintaining a constant velocity, which enables the pumping system to operate in a wide range of speeds with minimal variation, substantially increasing dispense performance and operation capabilities.

Abstract: Techniques herein describe a pumping system, adapted to reduce or eliminate fluid cavitation. Optionally, the pumping system is adapted for application to a passive fluid recovery system. In one example, the pumping system includes a pump and a thermal sub-cooling device. The thermal sub-cooling device may sub-cool fluid input to a pump and heat fluid output from the pump, particularly under start-up conditions. In a further example, a controller manages power supplied to both the pump and the thermal sub-cooling device, to transition from an ambient temperature start-up condition to an elevated temperature operating condition.

Abstract: A fan system includes a motor, a rotatable hub, and a plurality of fan blades. The motor is coupled with the hub by a hollow drive shaft, such that the drive system of the fan system is gearless. The motor is controlled by a PFC-based control module, which is in communication with sensors that are configured to sense parameters associated with operation of the fan system. The control module is configured to react in certain ways to certain conditions detected by the sensors, such that the fan system uses feedback-based control algorithms. A remote control panel is in communication with the control module. The remote control panel is operable to display fault conditions detected by the sensors. Blade retainers prevent fan blades from falling when a fan blade breaks free from the hub. Pins prevent the hub from falling when the hub breaks free from the rotor.

Abstract: An electric submersible pump contains an AC permanent magnet motor having three or more phases A, B, C and has a drive circuit for supplying varying drive signals to all the phases of the motor at the same time. Each drive signal is constituted by a cyclically smoothly varying voltage applied to the corresponding motor phase during driving of the motor. The circuit includes switches (902, 903) for each motor phase, a control arrangement for turning the switches (902, 903) on and off at a frequency greater than the frequency of the cyclically smoothly varying voltages, and a filter (907, 908) for filtering the output voltages of the switches (902, 903) to produce the cyclically smoothly varying voltages. Such a drive circuit drives all the phases of the motor continuously such that damaging transients will not arise and without requiring the motor emf or drive signals to be sinusoidal.

Abstract: The present invention relates to a control system for hermetic cooling compressor, which includes a reciprocating compressor (3) and an electronic control (2) for the reciprocating compressor (3), the electronic control (2) being configured for, after commanding the turning off of the reciprocating compressor (3), detecting whether the turn velocity (23) of the turning axle (10) is below a predefined velocity level, and then applying a braking torque (36) that causes deceleration of the turning axle (10) before completing the next turn of the turning axle (10), in case the turn velocity (23) detected is below the velocity level (34).

Abstract: A system may include a PWM generator and control logic. The PWM generator is configured to generate a PWM signal having a duty cycle dependent on a duty cycle value generated by the control logic. The control logic is configured to generate the duty cycle value to have a piecewise linear relationship with temperature such that at least two of a plurality of linear segments defined by the piecewise linear relationship have different slopes. In some embodiments, the piecewise linear relationship may be continuous.

Abstract: Peak performance of an electric motor can be enhanced by effective cooling of windings of the stator to avoid overheating. A liquid coolant is effective at cooling the stator; but in high-speed motors, it is advisable to avoid allowing coolant on the rotor to avoid high frictional losses. A shield provided in the air gap between the rotor and the stator guides the coolant back to a sump without gaining access to the rotor. Furthermore, if the electric machine is proximate a high temperature component, the shield may further prevent radiative and conductive heat transfer to the electric machine.

Abstract: Systems and methods including a motor or electromagnets to control the movement of one or more pistons in a pumping chamber. The pumping chamber may include a pump inlet and a pump outlet in fluid communication with the pumping chamber. Surfaces on a piston or pumping chamber may include hydrodynamic bearing surfaces.

Abstract: A computer and a control method for smart fan thereof are provided, wherein the computer includes a processor configured to control a smart fan under an UETFI bios mode. A sensed temperature value from a temperature sensor, and a current speed value of the smart fan are acquired. A real-time temperature curve and a real-time speed curve are traced in a dynamic updating zone of a graphical interface respectively according to the current temperature and the current speed value. A first control point and a second control point, which correspond to the smart fan, are obtained via a control zone of the graphical interface. A control curve is traced in the graphical interface according to the first and second control points. The speed of the smart fan is controlled according to the control curve.

Abstract: Detection of end of stroke for an electromagnetic pump may be performed using, for example, a calculated first flux derivative. Further, inductance of a coil that can be energized to produce a pump stroke may be calculated (e.g., the pump may include an actuator moveable in response to the energization of the coil). For example, the inductance may be calculated as a function of sense coil current and source electrical potential when the actuator is not moving for use in determining position of the actuator.

Abstract: A cyclic adsorption process is provided having pressurization and depressurization steps and driven by one or more centrifugal machines operating under acceleration and deceleration conditions wherein the deceleration rate of the machine is controlled to minimize power consumption and maximize the efficiency of the process. The operating speed of the centrifugal machine during deceleration is matched to the measured ratio pressure conditions so that the centrifugal machine arrives at its minimum operating speed near the point required to begin acceleration.

Abstract: A control system for a motor includes an angle determination module, a control module, an angle generation module, and an estimator module. The angle determination module generates an output rotor angle indicative of a desired angle of a rotor of the motor. The control module controls current supplied to the motor based on the output rotor angle. The angle generation module generates a commanded rotor angle in response to a commanded speed. The estimator module determines an estimated rotor angle of the motor. Upon startup of the motor, the angle determination module generates the output rotor angle based on the commanded rotor angle. Upon beginning of a transition period, the angle determination module generates the output rotor angle based on the commanded rotor angle and the estimated rotor angle. Upon ending of the transition period, the angle determination module generates the output rotor angle based on the estimated rotor angle.

Abstract: The present invention provides a sump pump control system. The system includes a mounting fixture fabricated from a corrosion resistant material, and an electrical control comprising solid state electrical components supported by the mounting fixture. The sump pump control system also includes a diving bell cover. The diving bell cover has an open bottom, and is dimensioned to cover the electrical components. The diving bell cover is releasably secured to a support surface of the mounting fixture. The electrical control controls the operation of a sump pump. Should water rise to a level of the electrical components due to failure of the sump pump or due to quickly rising water, the diving bell cover will prevent water from contacting the electrical components. A method of removing water from a subterranean vault is also provided herein.

Abstract: A metering system for metering a liquid has an electric motor (32) for setting a desired feed rate by modifying the rotation speed of the electric motor. It furthermore has an eccentric drive (52, 56), drivable by said electric motor (32), for a pump (53) that has two delivery directions. It also has a pump ring (62) made of an elastomeric material and a stationary ring (70) which is arranged relative to the pump ring (62) and to the eccentric drive (52, 56) in such a way that a pump chamber (120), extending in a circumferential direction, is formed between the stationary ring (70) and pump ring (62), which chamber changes shape upon rotation of the electric motor (32) in order to deliver a liquid to be metered through the pump chamber (120). A stationary seal (142) is provided in the pump chamber (120), between two fluid ports.

Abstract: A turbocharger comprises a turbine wheel and a compressor wheel mounted to a turbocharger shaft. An electric induction motor is provided for assisting rotation of the compressor wheel in predetermined circumstances. The motor comprises a fixed stator having motor field coils which generate a rotating magnetic field when energised by an AC control signal which induces eddy current flow in a rotor to generate a rotor magnetic field which in turn interacts with the stator magnetic field producing torque in the rotor.

Abstract: A method of controlling a fluid pump to supply lubricating fluid to a plurality of fluid requiring components in a hybrid vehicle powertrain includes selecting a component-required flow rate for each respective component using a determined operating speed and torque for that respective component. Once the each component-required flow rate is selected, the system flow rate is set to the maximum component-required flow rate of the plurality of component-required flow rates. The fluid pump is then commanded to supply fluid to each of the plurality of fluid requiring components at the system flow rate.

Abstract: A fan control circuit of a computer includes a fan interface connected to a connector of a fan, a fan controller, a NOT gate, and an electronic switch. The fan controller outputs a PWM signal to the fan interface to control the operation of the fan, and includes a GPIO interface to output a voltage control signal to the NOT gate to switch the electronic switch on or off. A signal output of the electronic switch is connected to the fan interface. The voltage control signal is high level at the start up moment of the computer, and thus does not turn on the fan via the electronic switch. After a preset delay period, the voltage control signal is turned low by the fan controller so that the fan interface receives the PWM signal.

Abstract: A pump (22) includes a pump casing (34) having a pump chamber (40), an impeller (30) received in the pump chamber (40), an electric motor (28) for driving the impeller (30), a detector (96) being configured for detecting a load on the pump (22), and a speed regulator (98) coupled to the detector. The speed regulator (98) is configured for decreasing the speed of the motor (28) to a speed greater than zero in response to the detector (96) detecting an unload condition of the drain pump (22).

Abstract: A method of operating a subsea compression system in a well stream, the subsea compression system comprising a compressor and an electromotor driven pump, wherein the compressor is configured to compress and the pump is configured to pump liquid from the compression system. The method comprises providing a gas return line connecting a downstream side of the compressor with an upstream side of the compressor, arranging a turbo-expander unit in flow connection with the gas return line, connecting the turbo-expander unit drivingly to a generator configured to charge a battery, operating the generator in response to recycling of compressed gas through the turbo-expander unit, and operating the pump on electrical power supplied from the battery.

Abstract: A method and apparatus for operating a vehicle HVAC system includes detecting an elevated risk of water splash expulsion from an evaporator through a vent outlet and controlling a voltage supplied to at least one blower of the vehicle HVAC system to reduce a risk of water splash expulsion if the elevated risk is detected. Water splash risk is determined in view of a voltage supplied to a subject blower, a vehicle tilt angle, and a condensation risk or value. The condensation risk or value is determined in view of a window open/close value, a temperature value, and a humidity value. Each of these factors are, either independently or in combination, compared with a corresponding threshold value to determine if the water splash risk warrants voltage control.

Abstract: Example devices, systems, and methods disclosed herein relate to controlling operation of a fire pump or jockey pump of a fire pump system. An example fire pump control system may comprise a jockey pump controller configured to control operation of a jockey pump and a fire pump controller configured to control operation of a fire pump. The jockey pump controller may be configured to determine a first pressure value based on an output of a jockey pump pressure sensor. The fire pump controller may be configured to receive the first pressure value from the jockey pump controller. The fire pump controller may also be configured to determine a second pressure value based on an output of a fire pump pressure sensor and select a predetermined action based on a comparison of the first pressure value and the second pressure value. Additional example devices, systems, and methods are described herein.

Abstract: Methods and systems for operating a fire pump controller are provided. An example method includes causing a power supply coupled to a an electric motor-driven water pump through a fire pump controller in a fire protection system to provide power to the water pump, and monitoring the performance of the power supply during the motor starting period by measuring the voltage and/or current of its output under motor load conditions. The method may also include providing visual indications, such as traces or starting signatures of motor power supply voltages and/or currents during the motor starting period for the purposes of observation and troubleshooting motor power supply and power train performance problems.

Abstract: [Object] To provide a vacuum pump, a vacuum exhaust device, and a method of operating a vacuum pump that are capable of achieving a stable exhausting operation without causing a step-out. [Solving Means] Provided is a method of operating a vacuum pump including a rotor (21, 22), a drive motor (35), and a magnetic coupling (50) configured to transmit a rotational force of the drive motor to the rotor at a rotational torque equal to or smaller than a first threshold value (Th1). The method includes detecting a load torque of the drive motor (35). The number of revolutions of the drive motor (35) is increased when the load torque is equal to or smaller than a second threshold value (Th2) that is smaller than the first threshold value (Th1). The number of revolutions of the drive motor (35) is reduced when the load torque exceeds the second threshold value (Th2) and is equal to or smaller than the first threshold value (Th1).

Abstract: A vacuum pump system includes a vacuum pump with a brushless, multi-phase, synchronous motor with a permanently magnetically excited rotor, and a pump type recognition element, a control unit for controlling the vacuum pump and having a drive microcontroller and a final stage, and a further microcontroller that monitors a rotational speed of the motor and turning off the final stage in case the rotational speed of the motor exceeds a maximum allowable rotational speed of the motor, and that forms part of the control unit.

Abstract: A fan control device includes a PWM generating circuit, a PWM switching circuit, and a switching instructing unit. The PWM generating circuit generates an arbitrary signal controlling rotation of a fan for cooling an MXM card. The PWM switching circuit is located between the MXM card and the fan, and switches output to the fan from the arbitrary signal generated by the PWM generating circuit to a signal output from the MXM card. The switching instructing unit issues a switching instruction to the PWM switching circuit at predetermined timing. Consequently, the fan control device can appropriately control the fan for cooling a heat-generating component.

Abstract: The present invention is a compressor compressing air, an electric motor driving the compressor, and an inverter variably controlling a rotating speed of the electric motor, the compressed air manufacturing facility is provided with a pressure sensor detecting a discharge pressure of the compressor at an upstream side position of a discharge air system connected to a discharge side of the compressor, and a control apparatus computing a pressure loss of the discharge air system in correspondence to a rotating speed of the electric motor, and changing a control range of the discharge pressure of the compressor at the upstream side position of the discharge air system on the basis of the computation in such a manner that a terminal pressure at a downstream side position of the discharge air system comes to a predetermined range.

Abstract: A micro cooling fan comprises a housing and a main circuit board. The housing has an accommodation space, a first inner surface, and a gap. The gap is in communication with the accommodation space, and two opposite side edges of the gap have a groove respectively. The main circuit board comprises a first circuit board and a second circuit board. The first circuit board has a stator, the second circuit board has a driving circuit, and the stator is electrically connected to the driving circuit. The first circuit board is disposed on the first inner surface, and the second circuit board is embedded into the grooves and blocks the gap.

Abstract: Some embodiments disclosed herein are directed to a pump assembly comprising a voice coil, a magnet and a diaphragm, wherein the voice coil is configured to move the diaphragm to pump a fluid through the pump assembly in response to a drive signal applied to the voice coil. Some embodiments disclosed herein are directed to an apparatus for applying negative pressure to a wound comprising a source of negative pressure configured to be coupled to a dressing, the source of negative comprising a voice coil actuator and a diaphragm, and a controller configured to produce a drive signal for the voice coil actuator.

Abstract: An integrated fuel pump and control system includes a pump assembly with an inlet and an outlet; a motor connected to the pump assembly to provide power to the pump assembly; a controller to regulate the speed of the motor; and a housing to contain the pump assembly, the motor and the controller.

Abstract: A controller that performs pulse width modulation control of a three-phase inverter circuit includes a three-phase modulation voltage command value generation unit, a two-phase modulation voltage command value generation unit, a voltage command switching unit, and a PWM signal output unit. The voltage command switching unit switches a voltage command value to a two-phase modulation voltage command value when a determination value becomes larger than or equal to a first threshold value, and switches the voltage command value to a three-phase modulation voltage command value when the determination value becomes smaller than a second threshold value, which is smaller than the first threshold value.

Abstract: This invention relates to programmable electronic device that prevents wastewater submersible and non-submersible pumps as well as viscous pumps from ragging therefore avoiding pump blockage. In one aspect the invention provides a pump apparatus comprising a pump and a control device for a pump, the pump being a mechanically switched pump such as a direct online/star delta pump and capable of being operated in a forward and a reverse direction, the control device comprising: a monitoring mechanism to monitor the torque of the pump, a control mechanism to control the direction of the pump and being capable of selectively directing the pump to (i) stop, (ii) operate in a reverse and (iii) operate in a forward direction; wherein the control mechanism is adapted to control the pump to do at least one of (a) stop and (b) operate in a reverse direction when the monitoring mechanism detects a pre-determined value in the torque of the pump.

Abstract: A device controls power supplied from an inverter having a semiconductor switching element to an electric compressor having an external drive source or a built-in motor. The device includes: an apparatus for calculating a starting current value required for starting the compressor from the pressure at the discharge side circuit of the compressor; an apparatus for calculating a permitted current value of the semiconductor switching element from the temperature of the inverter installation portion; and an apparatus for comparing the calculated compressor starting current value to the permitted current value of the semiconductor switching element so as to determine whether to permit a start of the compressor.

Abstract: A method of installing or retrieving a pumping system into or from a live wellbore includes connecting a lubricator to a production tree of the live wellbore and raising or lowering one or more downhole components of the pumping system from or into the wellbore using the lubricator.

Abstract: A controlling apparatus for reducing the variation of the liquid supply of a reciprocating pump is presented. The controlling apparatus for a reciprocating pump has a pump housing; a moving component for reciprocating in the pump housing so as to draw a liquid into the pump housing and discharge the liquid from the pump housing; a driving source for reciprocating the moving component; a setting unit for setting a target liquid supply amount or a target amount which corresponds thereto; a unit amount memory unit for storing a discharge amount of the reciprocating pump per a reciprocal movement of the moving component or a unit amount which is a value corresponding to the discharge amount; a computation unit for computing the smallest multiple number of the unit amount which is equal to or larger than the target amount; and a motor controller for controlling the driving source.

Abstract: A fan motor controller for a turbine engine comprises a component mounting base and a plurality of fan controller components mounted to the component mounting base. The component mounting base comprises a plurality of sections that are configured to extend circumferentially around a fan inner housing.

Abstract: An oil-flooded screw compressor drives a pair of rotors at a rotational speed which is low enough not to increase torque for a short amount of time after start-up and accelerates the pair of rotors up to a normal-operation rotational speed after oil discharge. Alternatively, the oil-flooded screw compressor rotates the pair of rotors for a short amount of time after the remaining compressed gas is discharged after a halt, thereby allowing the oil accumulated inside the working chambers to be discharged and ensuring smooth start-up after the halt.

Abstract: A fluid dispenser includes a container configured to store a fluid, a pump for placement in an interior of the container and for pumping contents of the container to an exterior of the container, a motor system for driving the pump and including a rotor for placement in the interior of the container, and a stator for placement on the exterior of the container, wherein an electric current is passed through the stator for causing rotation of the rotor.

Abstract: Disclosed is a system for controlling a pump, such as a submersible pump intended for pumping water, including a pump and a separate electronic control unit connected to the pump by an electrical cable. The control unit is adapted to be detachably connected to the pump, by that the control unit is adapted to allow the pumps power supply to pass through the control unit, by that an electronic controller is arranged in the pump for controlling at least one of the pump's functions and/or monitoring at least one of the pump's operating conditions, and by that the pump and the control unit are adapted to communicate with each other and transmitting signals, including necessary control and/or monitoring information/data, between each other.

Abstract: A system is provided and may include a compressor operable in a refrigeration circuit. A first sensor may detect high-side data indicative of an operating condition of a high-pressure side of the refrigeration circuit and a second sensor may detect low-side data indicative of an operating condition of a low-pressure side of the refrigeration circuit. Processing circuitry may receive the high-side data and the low-side data from the first and second sensors and may process the high-side data and low-side data to determine at least one of a low-side fault and a high-side fault. The processing circuitry may operate the compressor in a normal mode in the absence of a low-side fault and a high-side fault and may operate the compressor in a reduced-capacity mode or a shutdown mode based on a severity of the at least one of the low-side fault and the high-side fault.

Abstract: The invention relates to a method and a system for controlling a centrifugal pump (1) actuated by an electric motor (2). The control method comprises: a first step of selecting a speed and of controlling the variable speed drive (3) in order to apply said speed to the electric motor (2), a second step of controlling the solenoid valve (6) over the whole of its operating range at said selected speed, a third step of measuring the pressure and the flow rate of the fluid flowing in the pumping circuit and of measuring the electric power supplied to the motor for each operating point of the solenoid valve (6), a fourth step of determining, for said selected speed, the pressure curve as a function of the flow rate and the curve of the power supplied as a function of the flow rate.

Abstract: A cooling system for use in a portable communication device includes a detection module, a cooling module and a central control module. The detection module detects whether the portable communication device is in a communication state and generates an acknowledgement signal. The cooling module includes a fan and a driving unit. The central control module is electrically coupled to the detection module and the driving unit, detects an operational temperature of said device, and generates a detected temperature value corresponding to the detected operational temperature. The central control module controls the fan to operate in a silent mode or a cooling mode. The central control module controls the fan to operate in the silent mode if the central control module receives the acknowledgement signal when the detected temperature value is smaller than a temperature threshold value, else the central control module controls the fan to operate in the cooling mode.

Abstract: An electronically commutated pump motor circuit comprises an input configured, to receive at least a first range of voltages, and a power conditioning circuit. The power conditioning circuit includes an active power factor correction circuit, coupled to the input. The power conditioning circuit is configured to receive the first range of voltages and automatically output to an electronically commutated motor (optionally a pump motor) a substantially constant DC voltage for input voltages within the first range of input voltages, boosted with respect to a voltage received at the input, to thereby maintain a substantially constant motor shaft speed for any voltage within the first range of voltages.

Abstract: An electrical motor activation method for an electric motor including a rotor, connected to a motor shaft, and a stator having brushes. The stator comprises multiple commutator laminations for the commutation of windings disposed on the rotor and is activated by a pulsed or linearly controllable power source. The motor shaft is connected to a radially driven load, in particular a pump, which has a nonlinear torque curve via a motor revolution. A waviness signal is obtained from a voltage potential applied to the motor and/or from the motor current and rotor position information is obtained from the curve of said waviness signal.