Abstract: A shift range switching control device for switching a shift range by controlling driving of a motor includes a feedback control section, a stationary phase energization control section, and a switching control section. The feedback control section performs a feedback control based on an actual angle of the motor, and a motor speed. The stationary phase energization control section performs a stationary phase energization control which energizes a stationary phase selected according to the actual angle. The switching control section switches the control state of the motor.

Abstract: Provided is an evaluation device that determines the necessity of a notch filter inserted in a control system that controls an electric motor by closed loop control. The evaluation device includes: a characteristic acquisition parts for changing a parameter associated with a characteristic of the notch filter from a first value, which is a prescribed value, to a second value, and acquiring a change in a frequency response characteristic of the electric motor when the notch filter is applied; and a determination parts for determining the necessity of the notch filter based on the change in the frequency response characteristic that has been acquired.

Abstract: Setting of parameters that determine filter characteristics is facilitated. Machine learning of optimizing the coefficients of a filter provided in a motor control device that controls rotation of a motor for a machine tool, a robot, or an industrial machine is performed on the basis of measurement information of an external measuring instrument provided outside the motor control device and a control command input to the motor control device.

Abstract: A laser processing machine includes a processing head having a sensor, and a control unit to which a signal from the sensor is inputted. The control unit determines, by the signal, whether a drive shaft for the processing head needs to be adjusted. When the drive shaft is a state of needing adjustment, the control unit informs a display unit that the drive shaft is in a state of needing adjustment, and adjusts the drive shaft for the processing head by comparing data of a signal from the sensor with prestored data obtained during normal operation, in a different process than a laser processing process.

Abstract: A motor control apparatus includes: an oscillation instruction unit outputting an oscillation instruction signal; a filter unit performing filtering processing having frequency characteristic defined by a filter parameter; an oscillation forcing unit configuring a control loop in an oscillation period together with the filter unit, a current control unit, a motor, and a velocity calculation unit and causing the control loop to oscillate during the oscillation period in which the oscillation instruction signal is in the on-state; an amplitude evaluation unit acquiring, as an evaluation value, the amplitude ratio of an input signal to an output signal of the oscillation forcing unit when the control loop oscillates; and a filter adjustment unit comparing evaluation values provided when filter parameter candidates are set in the filter unit sequentially, selecting one of the filter parameters achieving a smaller evaluation value, and setting the selected filter parameter in the filter unit.

Abstract: A motor and control method for making the generating and regeneration efficiency higher than before are provided. A motor including a rotor, a storage battery and a capacitor (a source) is provided to charge a produced electrical energy, a SR motor portion rotates the rotor by magnetic force produced with a current supplied by the source and generates by converting rotational energy of the rotor into electrical energy, current sensors measure the currents supplied to excitation coils, and a semiconductor switching control circuit for driving and generation to maintain the rotation by increasing the current with supply of electrical energy from the source to the excitation coils if the currents measured by the current sensors fall below a predetermined lower limit for making the rotor rotate due to the charging.

Abstract: A method and a device are based on the application of an active correcting system with central corrector and Youla parameter for the attenuation of essentially monofrequency mechanical vibratory perturbations generated in a material structure by a rotating machine. Previously, a control law corresponding to a block modeling of the system is established and calculated, the blocks being, on the other hand, those of the central corrector and, on the other hand, a Youla parameter block, the modeling being such that only the Youla parameter, in the form of an infinite impulse response filter, has coefficients dependent on the vibratory perturbation frequency. During a phase of use, in real time, the frequency of the current perturbation is determined and the control law is calculated using for the Youla parameter the stored coefficients of a determined perturbation frequency corresponding to the current perturbation frequency.

Abstract: A motor driving circuit for driving a motor, includes: a detecting circuit configured to detect a detection signal indicative of a current state of the motor; a command value generating unit configured to generate a command value indicative of a target state of the motor; an error amplifier configured to generate an error signal by amplifying an error between the detection signal and the command value; a pulse width modulator configured to generate a pulse signal; and an output circuit. The command value generating unit is configured to provide a variation to the command value.

Abstract: Electrical tomography apparatus comprises: a first electrode; a second electrode; and current driving means for driving an electrical current between the first electrode and the second electrode through a medium, wherein the current driving means comprises: a first transformer having a first winding and a second winding, the second winding having a first terminal and a second terminal; and means for generating an alternating current through the first winding so as to generate an alternating voltage between said first terminal and said second terminal. The apparatus further comprises connecting means arranged to connect the first terminal to the first electrode and the second terminal to the second electrode. Generation of the alternating current in the first winding results in generation of an alternating voltage between the first and second electrodes. In certain embodiments, a current sensing transformer provides an indication of current driven through the medium.

Abstract: According to the present disclosure, a method of operating a wind turbine (10) coupled to a power grid (92) for delivering electric power thereto is provided. The method includes: a) operating the wind turbine (10) in a noise reduction mode; b) determining whether the power grid (92) is in an unstable grid state corresponding to an increase of power demand; and, c) increasing the electric power delivered by the wind turbine (10) to the power grid (92) during a stabilization time period for supporting stabilization of the unstable grid. Further, the increasing of the electric power for supporting stabilization of the unstable grid is performed such that a resulting noise increase is below a selected upper level. In addition thereto, a control system and a wind turbine for performing the above method are provided.

Abstract: A motor control device includes a PWM signal generation unit configured to increase/decrease duty in both leading and lagging directions regarding a phase in which the duty becomes maximum among three-phase PWM signals. The unit is also configured to increase/decrease the duty in one of leading and lagging directions regarding a phase in which the duty becomes minimum. Regarding a phase in which duty is intermediate between the phases, the unit is configured to increase/decrease duty in the other of the leading and lagging directions based on the phase, thereby generating a three-phase PWM signal pattern so that a current detection unit is capable of detecting two-phase currents at two time-points fixed within a carrier period of the PWM signal respectively. A duty compensation unit is configured to increase/decrease before and after changing an increasing/decreasing direction of three-phase duties, increasing/decreasing the duties to compensate for the duties.

Abstract: A detection control system includes a sensing unit, a control module and a driving module for a motor including a rotor and a stator. The sensing unit electrically connects the motor to sense a first and a second magnetic pole of the rotor cross a chip disposed between the rotor and the stator; a third magnetic pole is alternated to a forth magnetic pole of the stator to generate a sensing signal. A detection unit of the control module detects a kickback voltage value generated by a first current value changing to a second current value to calculate a minimum current value to generate a detecting signal. A timing unit receives the sensing and the detecting signal to calculate a first and a second period of time, and a discharging time. The driving module drives the rotor by receiving a control signal the control unit generates by controlling an alternating time.

Abstract: A lower limit value setting unit (52) variably sets a lower limit value (Vth) of a target voltage (Vh*) in a range of a voltage that is higher than the maximum value of voltages (Vb1, Vb2) of power storage devices and is not affected by a dead time provided for converters, based on temperatures (Tb1, Tb2) and required electric powers (Pb1*, Pb2*). A maximum value selection unit (53) sets the maximum value among the voltages (Vb1, Vb2) of the power storage devices and required voltages (Vm1*, Vm2*) of motor-generators, as the target voltage. A target voltage limiting unit (54) compares the target voltage with the lower limit value (Vth), and if the target voltage is lower than the lower limit value (Vth), the target voltage limiting unit (54) sets the lower limit value (Vth) as the target voltage (Vh*).

Abstract: Having a correlative relation indicator for indicating a correlative relation so that the supply current to be supplied to an inverter circuit may be varied proportionally to the voltage applied to the inverter circuit, a supply current value controller controls the average current to be supplied to the inverter circuit so as to be equal to the value of the supply current indicated by the correlative relation indicator, and therefore if the pressure loss or the static pressure is changed, a wind volume-static pressure of high precision extremely small in the changing amount of wind volume is realized.

Abstract: A variable-delay-time control system for a motor is provided. The system includes a control unit, a driving unit, and a motor. The control unit is used to output at least one control signal according to at least one predetermined signal, and the control signal has a variable delay time. The driving unit is connected to the control unit, and is used to receive the control signal and generate a driving signal. The motor is connected to the driving unit, and conduction time of the motor is controlled according to the driving signal and the variable delay time. With the variable-delay-time control system of the present invention, the delay time of the control signal is variable, so the motor can operate at a high efficiency (for example, at a reduced current). Moreover, as the variable-delay time can be adjusted according to the predetermined signal, the motor can operate at a high efficiency in different operating states, thus improving the overall efficiency of the motor.

Abstract: When cooling operation or dehumidifying operation is started, a blower fan for an evaporator and an exhaust fan for a condenser are driven at an initial rotational number. A compressor is driven at a fixed rotational number. Due to load variation, an operating current supplied from a power source is changed. When the operating current exceeds a reference value, the rotational number of the blower fan is gradually reduced. When an endothermic quantity by the evaporator decreases, a temperature of a gas refrigerant flowing through the evaporator is lowered. Since the load applied on the compressor is reduced, the operating current decreases. In this way, when the compressor is loaded, the operating current increased, however, by controlling operation of the fans as described above, it is possible to prevent that the power source is shut off due to overcurrent and operation is stopped.

Abstract: The present invention relates to a control system for protection against breakage of the lubricating-oil film in the bearings of hermetic compressors, as well as to a control method that has the objective of guaranteeing that a variable-capacity compressor should be maintained above a minimum rotation in order to prevent the oil film close to the respective bearing from breaking. One of the forms of achieving the objectives of the present invention is by means of a control system for protection against break of the lubricating-oil film in bearings of hermetic compressors, a microprocessor (10) actuating a set of switches (SW2M) selectively, so as to generate a rotation at the motor-compressor assembly (20, 21), the compressor (21) having a minimum rotation (RPMmin) of the compressor (21) so that the oil film will not be broken.

Abstract: The present invention discloses a control circuit for a variable frequency DC motor, the control circuit comprising: a controller, having a voltage sensing input end and a control output end, wherein the control output end is used to deliver an output signal according to the difference between a threshold voltage and the voltage at the voltage sensing input end; a transistor, having a first terminal, a second terminal and a third terminal, wherein the first terminal is coupled to the voltage sensing input end, and the second terminal is coupled to the variable frequency DC motor, and the third terminal is coupled to a reference ground; and a voltage divider, coupled between the second terminal and the third terminal, used to generate a feedback voltage for the voltage sensing input end; wherein the voltage at the second terminal is regulated according to the threshold voltage.

Abstract: A disc apparatus which can judge accurately whether or not a spindle motor is at fault due to a short circuit is provided. A disc apparatus (1) includes a spindle motor (3) which rotates a disc (2), a differential operational amplifier (5) which successively detects output voltages of the spindle motor (3), and a failure judgment unit (10) which calculates an average voltage of the plural output voltages and judges whether or not the spindle motor (3) is at fault in accordance with the average voltage and the output voltages. When counting number of occurrences of a specific state which indicates that one of the two output voltages detected successively is larger than the average voltage and other of the two output voltages is smaller than the average voltage, the failure judgment unit (10) judges that the spindle motor (3) is at fault.

Abstract: A fan speed control circuit is used for controlling rotation speed of a fan. The fan speed control circuit receives a pulse width modulation (PWM) signal from a system and comprises a programmable control unit and a current control unit. The programmable control unit receives the PWM signal, is connected to a Hall element for receiving a voltage signal therefrom, and provides a control signal. The current control unit takes the control signal to control current flowing through a stator coil unit of the fan so as to control the speed of the fan. The programmable control unit has a program written for the PWM signal, and when the fan speed control circuit is used in another system with a different PWM signal, the programmable control unit can be given a new program for the different PWM signal for controlling the speed of the fan.

Abstract: A control and motor arrangement in accordance with the present invention includes a motor configured to generate a locomotive force for propelling the model train. The control and motor arrangement further includes a command control interface configured to receive commands from a command control unit wherein the commands correspond to a desired speed. The control and motor arrangement still further includes a plurality of detectors configured to detect speed information of the motor, and a process control arrangement configured to receive the speed information from the sensors. The process control arrangement is further configured and arranged to generate a plurality of motor control signals based on the speed information for controlling the speed of said motor. The control and motor arrangement yet still further includes a motor control arrangement configured to cause power to be applied to the motor at different times in response to the motor control signals.

Abstract: A method of constant airflow control for a ventilation system is disclosed. The method includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes. This is because these controls use only intrinsic control variables which are electric current and rotational speed of the motor. Also, the method improves the accuracy of the control by correcting certain deviations that are caused by the motor's current-RPM characteristics. To compensate the deviation, the method adopts a test operation in a minimum static pressure condition.

Abstract: A switching regulation circuit for a dual-winding motor apparatus is provided. The switching regulation circuit comprises a gate-controlled device and a driving circuit. When one of the two windings generates an induced voltage signal greater than a threshold value, the driving circuit generates an output signal for turning on the gate-controlled transistor. Thereby, a parasitic diode of the gate-controlled device will not be turned on and damage the entire circuit.

Abstract: Disclosed is a starting device and method for eliminating a peak current introduced when an inductive circuit such as a motor or a direct-current (DC) motor is actuated, The starting device includes a signal generator electrically connected to the inductive circuit and generating a first signal corresponding to a signal output by the inductive circuit, a comparative circuit electrically connected to the signal generator for converting the first signal to a second signal to be compared with a reference signal to generate a control signal, and a controlling device electrically connected with the inductive circuit and the comparative circuit for receiving the control signal and gradually increasing a current input into the inductive circuit corresponding to the control signal, thereby eliminating the peak current introduced when the inductive circuit is actuated.

Abstract: A method and article of manufacture for monitoring an electrical energy storage device adapted to supply electrical power to a selectively actuable electric motor is described. This comprises determining a state of charge and a temperature of the electrical energy storage device subsequent to a stabilization period, and measuring a minimum voltage output from the electrical energy storage device during selective actuation of the electric motor. One of a plurality of predetermined threshold voltage states is selected based upon the state of charge and the temperature. The minimum voltage is compared to the selected predetermined threshold voltage.

Abstract: A method of constant airflow control for a ventilation system is disclosed. The method includes various controls to accomplish a substantially constant airflow rate over a significant change of the static pressure in a ventilation duct. One control is a constant I·RPM control, which is primarily used in a low static pressure range. Another control is a constant RPM control, which is primarily used in a high static pressure range. These controls requires neither a static pressure sensor nor an airflow rate sensor to accomplish substantially constant airflow rate while static pressure changes. This is because these controls use only intrinsic control variables which are electric current and rotational speed of the motor. Also, the method improves the accuracy of the control by correcting certain deviations that are caused by the motor's current-RPM characteristics. To compensate the deviation, the method adopts a test operation in a minimum static pressure condition.

Abstract: A drive control device is provided with a determining section and a voltage increasing section. The determining section determines if the actual acceleration is deficient in comparison with the acceleration requested by the driver or if the generator output is deficient in comparison with the acceleration requested by the driver. The voltage increasing section increases the voltage supplied to the electric generator from a vehicle mounted electric power source when the determining section determines that the actual acceleration or the generator output is deficient. As a result, the generator output deficiency is eliminated and the required motor torque is produced, thereby enabling the vehicle to start into motion appropriately in accordance with the acceleration requested by the driver.

Abstract: The rotational speed of a motor is detected, and stored in a rotational speed memory. The difference between the present rotational speed output and each of plural past rotational speeds stored in the rotational speed memory is calculated in a plural difference calculator. Whether the difference between the present rotational speed and the most past rotational speed out of the plural differences is larger than a first threshold value is judged. Whether at least one of the differences is larger than a second threshold value is judged. The first and second threshold values are set to values for detecting that the rotational speed of the motor has a decelerating trend through the comparison with the differences concerned, and the first threshold value is set to be smaller than the second threshold value. When both judgments have positive judgment results, it is judged that rotation abnormality of the motor occurs.

Abstract: A multi-speed permanent magnet D.C. electric motor system 10 includes at least one permanent magnet DC electric motor 11 configured to operate at at least one speed. A current limiting device R1 is constructed and arranged to lower electrical input power to the motor 11 so that a speed of the motor is reduced, when the motor is powered together with the current limiting device, as compared to a speed of the motor powered absent the current limiting device. Switching structure K1, K2, K3 is associated with the current limiting device to selectively operate the motor at at least three discrete speeds, even though the motor is configured for at least one-speed operation.

Abstract: The present invention provides a method and apparatus for providing power to a fan motor. One embodiment of the apparatus includes a boost regulator configured to provide an output current to a fan motor using an input current provided at an input voltage by a power supply. The fan motor is configured to draw the output current at a first frequency and the input current is constant within a first selected tolerance over a time scale longer than indicated by the first frequency.

Abstract: General purpose 100% solid state Direct Current drive for rotary DC machines with four quadrants operation. It is to say that allows the rotary DC machine to act like motor or generator in the two direction of possible rotation. In the first and third quadrant as motor in both direction of possible rotation, and in the second and fourth quadrant like regenerative brake DC generator, recovering the energy towards the DC network supply. To obtain that generalized control for DC machines of any type, the invention subject of this patent, is based on the interaction of two original ideas that they are: (1) Maintaining the direction, of the current in one and only one of the two main windings of the DC machine (7) either field or armature, by means of a rectifier bridge (6). (2) Use a DC controlled power supply (14), with reversible polarity to feed the complete machine.

Abstract: A system for controlling a motor for use in a ventilation system may include a motor, a voltage adjustment system, a user interface, and a motor controller. The voltage adjustment system may be configured to adjust a voltage applied to the motor. The user interface may be configured to receive patient settings input from a user and communicate target ventilation parameters to the motor controller. The motor controller may include a calculation engine configured to calculate motor performance parameters for achieving the target ventilation parameters, and based at least on the calculated motor performance parameters, perform a voltage adjustment analysis for controlling the voltage adjustment system. The motor controller may further include a voltage adjuster controller configured to activate the voltage adjustment system based on a first result of the voltage adjustment analysis and to not activate the voltage adjustment system based on a second result of the voltage adjustment analysis.

Abstract: A system for controlling a motor for use in a ventilation system may include a motor, a voltage adjustment system, a user interface, and a motor controller. The voltage adjustment system may be configured to adjust a voltage applied to the motor. The user interface may be configured to receive patient settings input from a user and communicate target ventilation parameters to the motor controller. The motor controller may include a calculation engine configured to calculate motor performance parameters for achieving the target ventilation parameters, and based at least on the calculated motor performance parameters, perform a voltage adjustment analysis for controlling the voltage adjustment system. The motor controller may further include a voltage adjuster controller configured to activate the voltage adjustment system based on a first result of the voltage adjustment analysis and to not activate the voltage adjustment system based on a second result of the voltage adjustment analysis.

Abstract: A driving circuit of an AC fan motor has an AC to DC converter, a current detecting unit, a step-down divider, a motor driving unit, two windings each having many coils and a harmonic wave elimination unit. The AC to DC converter converts AC power to high voltage DC power. The motor driving unit is connected to the step-down divider to obtain low voltage DC power to operate. The two windings are directly connected to the AC to DC converter through the current wave detect unit to obtain the high voltage DC power. Therefore, the current wave detecting unit can response current changes of windings and then an operator can simulate present current wave of the windings to determine the present operating status of the AC fan motor.

Abstract: General purpose 100% solid state Direct Current drive for rotary DC machines with four quadrants operation. It is to say that allows the rotary DC machine to act like motor or generator in the two direction of possible rotation. In the first and third quadrant as motor in both direction of possible rotation, and in the second and fourth quadrant like regenerative brake DC generator, recovering the energy towards the DC network supply. To obtain that generalized control for DC machines of any type, the invention subject of this patent, is based on the interaction of two original ideas that they are: (1) Maintaining the direction of the current in one and only one of the two main windings of the DC machine (7) either field or armature, by means of a rectifier bridge (6). (2) Use a DC controlled power supply (14), with reversible polarity to feed the complete machine.

Abstract: The rotational speed of a motor is detected, and stored in a rotational speed memory. The difference between the present rotational speed output and each of plural past rotational speeds stored in the rotational speed memory is calculated in a plural difference calculator. Whether the difference between the present rotational speed and the most past rotational speed out of the plural differences is larger than a first threshold value is judged. Whether at least one of the differences is larger than a second threshold value is judged. The first and second threshold values are set to values for detecting that the rotational speed of the motor has a decelerating trend through the comparison with the differences concerned, and the first threshold value is set to be smaller than the second threshold value. When both judgments have positive judgment results, it is judged that rotation abnormality of the motor occurs.

Abstract: The speed control apparatus comprises a plurality of Hall sensors, a plurality of switches, a turn-on control circuit, and a gate drive logic. The Hall sensors are configured to detect magnetic rotor sections of a poly-phase brushless DC motor at different positions. The switches apply voltages on a plurality of windings to respectively produce magnetic north or south on stator poles of the poly-phase BLDC motor. The turn-on control circuit generates a conduction time reduction after each output transition of the Hall sensors. The gate drive logic separately turns on or turns off the switches according to different output transitions of the Hall sensors to respectively apply voltages on the windings with the conduction time reduction.

Abstract: Practically ideal electrical resonance is employed to soley provide armature power, and stator power if desired, to run DC motors. A practically ideal parallel resonant tank circuit (PIPRC) is used wherein the quotient of the “tank current” divided by the “line current” (called the “quality” or “Q” of the tank) is (1) greater than one, (2) large enough to allow the percent efficiency of the electric motor to be equal to or greater than 95%, and (3) removes enough back emf or enough of the influence thereof so that criteria (1) and (2) can be realized throughout the entire operating range of the motor. Only one PIPRC is needed for a DC motor. Recontrolling and/or redesigning is done for two reasons.

Abstract: A vector control device of a winding field type synchronous machine with which even when voltage changes caused by resistance voltage falls and inductance fluctuations due to armature current occur the armature voltage is controlled exactly to a desired command value and a high power supply utilization percentage is maintained at all times. An absolute value of armature voltage is calculated from an armature voltage command value or an armature voltage detected value, and the armature voltage is controlled by a flux command being regulated so that this absolute value of armature voltage approaches a desired armature voltage command value. Also, the armature voltage command value is regulated so that the loss of the synchronous machine becomes minimal with reference to the armature current and the field current.

Abstract: A motor driving apparatus includes a power circuit that controls an output voltage via a feedback resistance. The power circuit varies the output voltage by changing a value of the feedback resistance at a time of at least one of activation and termination of a motor, thereby enabling to activate the motor at any one of a high speed and a low speed.

Abstract: A power supply apparatus driving and controlling motor generators (MG1, MG2) includes a battery (10) generating an input voltage (Vb), a converter (110) converting the input voltage into a motor operating voltage (Vm) according to a voltage command value (Vmr), a smoothing capacitor (120) holding the motor operating voltage, inverters (131, 132) receiving the motor operating voltage and driving and controlling the motor generators (MG1, MG2) according to a torque command value (Tref), and a control unit (15) generating the voltage command value and the torque command value.

Abstract: A speed control apparatus includes a speed control part 12 for generating a source current command based on a difference between a speed command of a motor 4 and speed detection in which a speed of the motor 4 for driving a load 2 is detected, a notch filter 14 which can break a notch frequency resulting in a predetermined frequency selected among continuous frequency band widths and also generates a compensating current command in which the notch frequency is eliminated from the source current command signal, a notch filter adaptive part 16 for selecting the notch frequency so that the compensating current command in which a sustained vibration frequency component of the source current command is eliminated is generated from the notch filter 14, a subtracter 103 for generating an elimination portion current command resulting in a difference between the source current command and the compensating current command, and an adder 109 for adding the compensating current command and the elimination portion current

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: A method and system for determining a torque current in an electric machine coupled to a polyphase bus. The method comprises: detecting a rotational position of the electric machine with a position encoder; controlling an inverter comprising a plurality of switching devices, the inverter having an input coupled to a direct current bus, and an output coupled to the polyphase bus. Where the inverter is responsive to commands from a controller coupled to the inverter and to the position encoder. The method also includes measuring a current from the direct current bus; and capturing the current at a predefined interval of time.

Abstract: Apparatus including a DC-DC converter that applies a variable voltage to an inductive load, such as a fan motor. The converter has a low-frequency high dynamic output impedance and applies a variable voltage from its output to the inductive load. A transient limiter, such as a capacitor, is connected in parallel with the inductive load to minimize the amplitude of transients generated by the load during the reception of the variable voltage from the converter. The converter has a low frequency of operation to inhibit the generated transients from being extended to a DC power source connected to the input of the converter. This prevents the transients from being applied to other circuits served by the DC power source. The fan may be used to provide cooling for the apparatus of which the DC-DC converter is a part.

Abstract: Systems and methods are provided through which the current to a spindle motor of the recording medium of a mass storage device is modulated to avoid anomalies in the operation of mass storage device and reduce power consumption. In the example of a disc drive, the current is modulated to prevent expected or predicted disturbances in the air bearing between a read/write head and the recording medium, and to reduce the power consumption when no disturbances are predicted or expected.

Abstract: A radiator includes a voltage regulator for providing a reference voltage, a fan including a power end connected to the reference voltage via a first resistor and a feedback end for outputting a pulse signal indicating the rotation speed of the fan, an integration circuit including an output end, and an input end connected to the feedback end of the fan for converting the pulse signal from the feedback end into a voltage signal, and a thermistor connected between the output end of the integration circuit and the reference voltage, for detecting temperature changes in order to adjust the rotation speed of the fan.

Abstract: Systems, methods, and apparatus, consistent with principles of the present invention, allow an unmodified device, for example, a dc starter motor, that normally operates at a first voltage to function in an electrical system providing a second voltage, which is different from the first voltage, and received from the power source. A device actuator, such as a solenoid, is controlled using the second voltage. The first voltage is produced and supplied to the device in response to a first action of the actuator, for example, upon solenoid depression. This voltage is then inhibited from being provided to the device in response to a second action of the actuator, for example, upon solenoid retraction after engine cranking.

Abstract: Various systems and methods are provided for cooling a cabinet. In one embodiment, a method is provided that comprises the steps of controlling a speed of the at least one cooling fan in response to a temperature of the cabinet, and, controlling the speed of the at least one cooling fan in response to a position of an access panel relative to the cabinet.

Abstract: A hand-held, battery powered tool (e.g., nutrunner, drill) includes an output head operatively connected to a motor, a plurality of battery cells, an ON/OFF start switch, a resistance sensor that measures a resistance of the output head to movement, and a controller. When the start switch is ON and the resistance sensed by the resistance sensor does not exceed a predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other and the motor in series. When the start switch is ON and the resistance sensed by the resistance sensor exceeds the predetermined shift resistance, the controller automatically connects the plurality of battery cells to each other in parallel and to the motor.