Abstract: A surgical device comprising a first clamping member, a second clamping member, an electric motor, and a control system is disclosed. The electric motor is configured to drive at least one of the first clamping member and the second clamping member toward a predetermined tissue gap between the first clamping member and the second clamping member to clamp the tissue of a patient. The control system is configured to monitor a parameter of the electric motor. The parameter is indicative of a clamping force exerted to the tissue by the first clamping member and the second clamping member. The control system is further configured to control the electric motor based on the parameter to limit the clamping force to a predetermined maximum limit.

Abstract: A surgical device comprising a staple cartridge, a clamping mechanism configured to clamp patient tissue, a firing member, a manual bailout, an electric motor, a power source, and a control unit is disclosed. The clamping mechanism comprises a first iaw and a second iaw. The firing member configured to engage the first jaw and the second jaw during a closure stroke. The second jaw is moved to the closed position during the closure stroke and the firing member is further configured to eject staples from the staple cartridge during a firing stroke. The manual bailout is configured to retract the firing member through a retraction stroke. The electric motor is configured to drive the firing member. The control unit is configured to monitor a parameter of the electric motor and control the amount of current supplied to the electric motor based on the parameter.

Abstract: The present invention relates to a motor control method for a dental handpiece provided with a motor that rotationally drives a cutting tool. The control method includes a step A of limiting the motor current to a first limit current I1 when the load torque applied to the cutting tool exceeds a preset limit torque value, and a step B of controlling the motor current to be equal to or lower than a second limit current, which is lower than the first limit current, when it is detected that the motor stops rotating.

Abstract: A system and method for determining the start position of a motor. According to an embodiment, a voltage pulse signal may be generated across a pair of windings in a motor. A current response signal will be generated and based upon the position of the motor, the response signal will be greater in one pulse signal polarity as opposed to an opposite pulse signal polarity. The response signal may be compared for s specific duration of time or until a specific integration threshold has been reached. Further, the response signal may be converted into a digital signal such that a sigma-delta circuit may smooth out glitches more easily. In this manner, the position of the motor may be determined to within 60 electrical degrees during a startup.

Abstract: A drive system for an electrical machine is provided. The system includes a control unit and a monitoring unit, which is independent of the control unit. The control unit includes a device that converts one or more incoming operating parameters of the electrical machine to an output value. The monitoring unit includes a device that converts the operating parameters to a comparison value, with the conversion being carried out more quickly in the control unit than in the monitoring unit. A comparator compares the output value or an intermediate value of the output value with the comparison value of the output value or of the intermediate value.

Abstract: A power supply control device controls a power supply connected to a motor and includes: an AC/DC converter that makes a first DC power supply; a DC/DC converter that makes a second DC power supply out of the first DC power supply; a first rectifying element that allows current to flow from the first DC power supply toward the motor; a second rectifying element that allows current to flow from the first DC power supply toward the DC/DC converter; and a third rectifying element that allows current to flow from the motor toward the DC/DC converter. In this way, a power supply connected to a motor can be suitably controlled.

Abstract: A hand-guided or stationary power tool has a drive unit having a motor that includes a rotor having a permanent magnet and a stator and has a motor control designed to trigger the motor in a first rotational speed range according to a voltage-controlled mode and to trigger the motor in a second rotational speed range following the first rotational speed range in the direction of a higher rotational speed according to a field-weakening operation.

Abstract: A control device of a fan system includes a temperature sensing module, a comparing module and a driving module. The temperature sensing module senses an external temperature and generates a sensing signal according to the external temperature. The comparing module receives the sensing signal and outputs a comparing signal according to the sensing signal and a reference voltage signal. The driving module, which is electrically connected with the temperature sensing module and the comparing module, supplies a working voltage to the temperature sensing module and the comparing module, and outputs a rotating speed control signal according to the sensing signal or the comparing signal.

Abstract: A vehicle mirror device includes a drive unit to turn a mirror unit with respect to a base unit. The drive unit includes a motor and a control circuit. The motor is driven with a battery voltage. A current supply to the motor is cut OFF when a motor current flowing in the motor exceeds a threshold, and the control circuit changes the threshold depending on the battery voltage.

Abstract: A device for correcting a digital estimate of an electric signal is described. The device includes a comparator that generates a current proportional to the difference between an analog estimate signal, which derives from the digital estimate, and the electric signal. The device also includes a capacitor positioned to be charged by the current, a transistor that discharges the capacitor, and a comparator that compares the voltage at the terminal of the capacitor with a reference voltage. The device also includes a controller that drives the transistor in response to the output signal of the comparator and a logic device that generates a correction digital signal to be added to or subtracted from the digital estimate of the electric signal in correspondence of an ascending or descending waveform of the electric signal.

Abstract: An electric fan temperature-rated variable speed control circuit, includes a D.C. current source and fan activation IC. There are, between the current source positive and negative poles serially connected transistor, regulation tube, with the regulation tube negative pole linked to the current source negative pole, and its positive pole, incorporated to form the primary current. Between triode base and collector lies a serially connected resistor. The triode collector is linked to the current source positive pole, and between its base and collector lies a serially connected rectifying resistor, which bypasses through the base to connect with the fan activation IC for sending out fan rotation speed control signals with which to form a circuit that adopts a straightforward, easy-to-implement method that offers low-cost and dependable temperature-control characteristics.

Abstract: The present invention provides a method for shifting the instant of commutation for a sensorless and brushless direct-current motor (1), whose stator windings are fed by a multi-phase converter connection. The converter connection includes an output stage control (2), a commutation logic (3), a phase selector (4), and phase discriminator (5). A commutation detection (6) is supplied at one input (46) with the instantaneous value of the voltage induced in a phase, the instantaneous value being determined by the phase selector, and at a second input (47), with a reference voltage (Uref) for comparison. The reference voltage (Uref) can be changed by a commutation shift (7) in correspondence with a specific characteristic curve (71). A manipulated variable (Ust) is supplied by a manipulated-variable calculation (8) to the commutation shift (7) as a function of the setpoint speed (Nsetpoint) of the motor. The commutation shift takes place in an advantageous manner in a parabola shape.

Abstract: A fan motor driving circuit of the present invention comprises a device for detecting a power source voltage and outputting a voltage in proportion to a difference between the power source voltage and a predetermined rated voltage when the power source voltage is greater than the rated voltage. The driving circuit also includes a device for controlling a rotary speed of a fan motor to a predetermined value by automatically varying a first signal input to a conducting current generating circuit for determining the rotary speed of the fan motor according to an output voltage of the power source voltage detecting means when the power source voltage is greater than a predetermined value.

Abstract: A variable speed power tool may include a speed adjusting device and/or a maximum speed adjusting device for adjusting the operating speed, and a fixed operating speed switch. An operator adjustable speed adjusting device having a position maintaining mechanism also may be utilized. When manipulated by the operator, the fixed operating speed switch gives priority to the adjusted position of the speed adjusting device and adjusts the operating speed to a preset operating speed. In the alternative, a switching device and an internal integrated circuit may be utilized to adjust the operating speed to a target speed using feedback control. The switching device preferably selects a voltage corresponding to the target speed from either a voltage representative of the position of the speed adjusting device or a predetermined voltage representative of the present operating speed.

Abstract: An apparatus (10) for controlling an electric motor (36) having a plurality of motor phases includes a motor controller (32) that controls energization of each phase of the plurality of motor phases. A compensation circuit (56, 84, 104) is associated with each phase of the plurality of motor phases. The compensation circuit (56, 84) of one phase of the plurality of motor phases adjusts a control parameter of another phase of the plurality of motor phases an amount functionally related to an electrical characteristic of the one phase in response to determining a diminished operating characteristic of the one phase.

Abstract: A motor constant Km of a sled mechanism of an optical disc drive is to be measured. To this end, a parameter measurement device 1 for the sled mechanism includes an oscilloscope 8 for detecting the back-electromotive force Eb of a sled motor 5, a laser Doppler meter 7 for detecting the movement velocity v0 of the pickup 4 and a computer 9. The computer calculates an equation Eb=KmRmv0, where Rm is the resistance of a motor, to find the motor constant Km.

Abstract: An apparatus for controlling an actuator in response to a target speed voltage signal, the actuator having a moveable member and having a coil that influences movement of the member. A first summing node is provided having a control output voltage, for summing or subtracting voltages applied thereto, as the case may be and receiving the target speed voltage signal at a first, summing input thereto. A proportional compensation unit is provided, receiving the control output voltage and providing as an output a proportionally compensated output signal. An integral compensation unit is provided, receiving the control output voltage and providing as an output an integrally compensated output signal. An inverse compensation unit is provided, receiving the target speed voltage signal as an input and providing an inversely compensated output signal having a voltage corresponding to the voltage of the target speed voltage signal multiplied by the inverse of a predetermined amplification factor.

Abstract: A speed control for controlling the speed of a DC motor provides improved speed regulation during transient loading conditions. The control includes a regulating circuit having an output for controlling the armature voltage to the motor, An input speed reference signal corresponding to the desired speed is provided to the regulating circuit. A feedback signal proportional to armature voltage is also provided to the regulating circuit to establish an error signal for operating the control to regulate the voltage to the motor and therefore the motor speed, An IR compensating circuit provides increased motor voltage when the load increases. The voltage drop due to the armature circuit inductance is measured directly and also utilized to alter the output of the regulator to compensate for the inductive voltage drop occurring under transient loading conditions in a manner tending to establish the speed at the desired speed corresponding to the speed reference signal, during such conditions.

Abstract: A speed controller includes a drive source, an input device for inputting the driving speed information of the drive source, a driver for driving the drive source on the basis of the driving speed information input by the input device, a detector for linearly detecting the amount of movement of the drive source an output device for outputting movement amount information obtained by the detector, and a corrector for correcting the driving speed information by the use of the movement amount information obtained by the detector, the corrector imparting new driving speed information as the corrected value to the driver.

Abstract: A motor controller for brushless motors operates an inverter in a current-controlled mode for low motor speeds and in a voltage-controlled mode for high motor speeds. By switching from the current-controlled mode to the voltage-controlled mode at higher speeds, the motor can be designed at maximum efficiency, and minimum weight, cost and volume.

Abstract: A load driving circuit causes a driving current to flow through a load, such as a reel motor, an audio load or the like through the collector and emitter of a drive transistor. A load voltage which changes according to changes in the driving current is obtained at a point of connection between the drive transistor and the load. On the basis of the load voltage, an offset voltage having a predetermined constant value is generated in a power supplying circuit so as to cancel a change in the load voltage. The offset voltage is supplied as driving source output to the drive transistor so as to prevent the generation of excess heat in the drive transistor even if the driving current changes.

Abstract: A blower motor drive control circuit is configured to maintain a fixed value of motor driving current to maintain a constant amount of air supply from an air conditioner regardless of changes in the amount of intake air.

Abstract: In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus having a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output of the driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.