Abstract: An abnormality monitoring device monitors a PWM driving signal output from a driving section of an associated motor control system to judge whether the driving section is operating abnormally. By monitoring the output of the driving section, the monitoring device can detect an abnormality of the driving section before the motor can respond to the abnormal drive signal to a significant degree (e.g., to a degree readily discernable to a rider of a motorcycle on which the motor control system is employed in combination with an electronic throttle system).

Abstract: A dual motor arrangement includes a first motor M1, a first MOSFET Q1 constructed and arranged to control operation of the first motor, a second motor M2, a second MOSFET Q2 constructed and arranged to control operation of the second motor, an RFI filter structure L1, C_RFI, a freewheeling circuit L2, C2, and a controller S. The controller is constructed and arranged to provide a first PWM signal to the first MOSFET and a second PWM signal to the second MOSFET. The second PWM signal is in staggered time relation with respect to the first PWM signal. When one motor is in a freewheeling mode of operation for at least a portion of a time that the MOSFET, associated with the other motor, is on, freewheeling of the one motor decreases an amount of current drawn by the other motor during turn on of the other motor. The inductors L1, L2 can be coupled to define a transformer.

Abstract: A controller of a pulse width modulation signal-driven device, includes: an instruction input of operating the pulse width modulation signal-driven device; a control section generating a control clock which operates the pulse width modulation signal-driven device; a frequency modulator frequency-modulating the control clock, to thereby give to the control clock a frequency variation in a predetermined frequency range; a frequency varier generating a modulation signal inputted to the frequency modulator; and a first switching member driving the switching element which flows a predetermined drive current to the pulse width modulation signal-driven device based on the frequency-modulated control clock. The frequency varier includes: a first signal generator setting a range of diffusing a switching noise in a frequency range, and a unit for shifting a frequency band of the switching noise by giving a predetermined offset voltage to an output voltage of the first signal generator.

Abstract: A system and method for reducing fan noise by controlling the drive current to the fan motor. In one embodiment the system approximates a linear drive using a number of transistors in parallel and sequentially deploying the transistors. In another embodiment, a scheme is used to activate and deactivate transistors in discrete steps thereby achieving the benefits of the linear controller topology.

Abstract: A fan motor speed control circuit is disclosed. The circuit includes a digital/analog converting unit and a driving unit. The digital/analog converting unit takes charge of receiving a pulse width modulation (PWM) signal and converting it into a voltage signal. The driving unit is connected with the digital/analog converting unit in series for receiving the voltage signal, while the driving unit provides a first predetermined voltage level and a second predetermined voltage level as references. The fan motor is kept to run with a low constant rotation speed when the voltage signal level is higher than the first predetermined voltage level, with a full constant rotation speed when the voltage signal level is lower than the second predetermined voltage level, and with a variable rotation speed when the voltage signal level is lower than the first predetermined voltage level and higher than the second predetermined voltage level.

Abstract: A self-startup circuit for a DC fan includes a voltage sampling device receiving a first control signal, a comparator, and a self-startup device. The comparator includes two input terminals and an output terminal. One input terminal is connected to an output terminal of the voltage sampling device. The self-startup device has a switching device and a diode connected in parallel. The self-startup device has an input terminal connected to the output terminal of the comparator, and outputs a second control signal for keeping the DC fan rotating even when the first control signal has a very low duty cycle.

Abstract: The invention relates to a circuit and a method for the speed control of a d.c. motor, particularly the speed control of a fan driven by this d.c. motor, which is used as part of an air distribution system in passenger and commercial motor vehicles. The circuit for the speed control of a d.c. motor includes, according to the invention, a d.c. motor and a supply voltage supplying this d.c. motor, a control module for the generation of PWM-signals and registration of measurement currents and measurement voltages, a number n of parallel-connected field effect transistors which are designed suppliable with PWM-signals in a cascade manner to switch the d.c. motor, and a number n?1 resistors which are designed each to be connected with one of the n field effect transistors which are designed each to be connected with one of the n field effect transistors, whereby n is at least 2.

Abstract: A motor control device selectively turns on or off a drive transistor in-accordance with a PWM control signal Sp, such that a drive current Im supplied to a motor is adjusted. The device also samples and holds a motor current Sm for obtaining a motor current value Ih. With reference to the motor current value Ih, the device protects the motor from an overcurrent. Sampling and holding of the motor current Sm is performed for a sampling and holding time Ts. The sampling and holding time Ts corresponds to a time period between a first point in time when the level of the PWM control signal Sp is switched for turning off the drive transistor and a second point in time that precedes the first point in time by a predetermined period. As a result, the motor current value Ih is detected with high accuracy.

Abstract: A circuit system that includes a sensor circuit for a sensor that detects the state of a motor is provided in an inverter unit for driving the motor. A 0V of the circuit system is connected with a shield braid of a shielded cable that connects the sensor circuit and the sensor. Further, the shield braid of the shielded cable is connected to an earth plate.

Abstract: In the invention, a PWM signal is formed at a frequency of a reference pulse signal, the PWM signal which has a pulse width being changed according to a frequency difference between an FG pulse signal for detecting a speed of a brushless motor and the reference pulse signal of a target speed, an output signal for PWM control is formed by an N-fold frequency of the PWM signal, the output signal for PWM control in which a pulse having the divided pulse width is arranged in each N-divided period, the N-divided period in which each one period of the PWM signal is divided by N, and electric power supply to a coil of each phase of the brushless motor is turned on and off at intervals shorter than that of the output signal control without increasing the frequency of the reference pulse signal.

Abstract: Amperage control of a power tool motor is provided by pulse width modulation of current from a power supply. The pulse width modulation may be varied according to the determined motor current and measured power supply voltage. The power supply preferably includes a battery, such a lithium ion or nickel cadmium.

Abstract: A system includes a motor for producing motion when current is supplied to the motor and a motor controller coupled to the motor for receiving a motor current signal indicative of the current supplied to the motor. The motor controller has an analog-to-digital converter for converting the motor current signal to a sampled motor current signal. The motor controller is operable to detect pulses in the sampled motor current signal, count the detected pulses to generate a first pulse count, and determine a run parameter for the motor based on the first pulse count. A method for controlling a motor includes counting a first plurality of pulses in a motor current signal produced while the motor is activated to generate a first pulse count. A second plurality of pulses is counted in the motor current signal produced while the motor is deactivated to generate a second pulse count. A run parameter for the motor is determined based on the first and second pulse counts.

Abstract: When a PWM signal generating unit (10) sets a duty D of a PWM signal based on command signals (10c), the PWM signal generating unit (10) sets a phase difference ? between each of the PWM signals based on a relation formula of ? (degree)=360 (degree)×D (%)/100 (%), and generates and outputs first PWM signals (10a) and second PWM signals (10b) in which the duty is D (%) and the phase difference is ? (degree). The first PWM signals (10a) and the second PWM signals (10b) are respectively supplied to a first load driving circuit (21) and a second load driving circuit (22) to operate a first motor fan (3) and a second motor fan (4) by a PWM control, respectively.

Abstract: A system and method for measuring the speed of a fan in an electrical system is presented. The duty cycle of a pulse width modulated (PWM) signal provided by a signal generator may control the speed of the fan. The fan may generate tachometer pulses that may be used by a tachometer reading-unit to monitor the RPM of the fan. Very low frequency test (VLFT) pulses may be generated and provided through a sampling signal multiplexed with the PWM signal to sample the fan generated tachometer pulses even when the PWM signal is low. The frequency of the sampling signal may be determined based on the duty cycle of the PWM signal and may be dynamically updated when the duty cycle of the PWM signal is updated. The sampling signal may be used as the clock input to a flip-flop with the tachometer pulses as the data input, and the output of the flip-flop providing an input to a pulse counter that counts the number of pulses within a determined period of time, providing as its output the measured RPM of the fan.

Abstract: A method and apparatus for controlling a fan is disclosed. In one embodiment, a method for controlling a fan includes applying power to the fan at startup. The fan may be supplied a predetermined amount of current, which may break the inertia of the fan propeller and begin its rotation. As the propeller begins rotating, the speed at which it rotates may be monitored. The fan startup routine may continue until the fan reaches or exceeds a minimum fan speed threshold. Once the fan has at least reached the minimum speed, the amount of current supplied to the fan may be reduced such that the fan rotates at minimum speed, and an automatic fan control algorithm may begin executing. By reducing the current such that the fan operates at a minimum speed, the amount of audible noise generated by the fan during startup may be kept to a minimum level.

Abstract: A system and method for generating a test signal used in measuring the speed of a rotating device, such as a fan in a computer system is disclosed. A pulse width modulated (PWM) signal may power the fan with the duty cycle of the PWM signal controlling the speed of the fan. The fan may generate tachometer pulses used for monitoring RPM of the fan. The frequency of the test signal may be selected to be at least twice the frequency of the tachometer pulses. The test signal may be generated from a base frequency signal using two cascaded frequency dividers. The first divider may output a scaled base frequency signal obtained by dividing the base frequency signal by a user programmable scale frequency coefficient corresponding to a maximum test signal frequency for the fan. The second divider may output the test signal by dividing the scaled base frequency signal by a fraction frequency coefficient obtained from and proportional to the current PWM duty cycle value.

Abstract: In order to design as inexpensively as possible a control device for DC motors which are provided with a commutator for feeding their motor windings which has at least four sliding contacts, this device comprising a modulation stage which generates at least one control signal modulated as to pulse width with a clock frequency substantially above the motor speed and a control circuit which is controlled by the at least one control signal and has at least one load branch which feeds the commutator and is provided with an electronic switch controlled by the control signal modulated as to pulse width, it is suggested that the sliding contacts be combined to form at least two control groups, that the sliding contacts be combined within each control group to form pairs of sliding contacts and that each control group have its own load branch associated with it.

Abstract: A driving circuit for switches of direct current fan motor is disclosed. The driving circuit includes a plurality of switches, a first control circuit, and a second circuit. The switches are driven by a first pulse width modulation signal and a second pulse width modulation signal, and they are electrically connected with the direct current fan motor in a bridge manner. A third pulse width modulation signal is used to drive the first control circuit connected to at least one of the switches driven by the first pulse width modulation signal. A fourth pulse width modulation signal is used to drive the second control circuit connected to at least one of the switches driven by the second pulse width modulation signal. Especially, either the first pulse width modulation signal or the second pulse width modulation signal is selected as the third pulse width modulation signal or the fourth pulse width modulation signal.

Abstract: A powered tool for performing surgical procedures. The tool includes a handpiece in which a power generating unit is housed. A control member is mounted to the handpiece. The control member is mounted to the handpiece so that the orientation of the control member can be selectively set relative to the point to which it is mounted to the handpiece and so it can move relative to a reference point on the handpiece. A control module monitors the orientation of the control member and its position relative to the reference point. Based on the control member orientation and position, the control module generates signals to regulate the operation of the power generating unit. When the power generating unit is a motor, the control module generates signals to ensure that the maximum speed at which the motor can be driven is less than the no load speed.

Abstract: A programmable high-speed motor torque controller is provided. A current mode PWM controller widely used in the switching power supply is utilized to perform a real-time hardware control on the operating current of a motor. A microprocessor is used as an operating and controlling interface. By means of the output signal from the switching element of the current-limiting switching controller, the gate switch elements (MOSFET/IGBT) are further controlled so as to control the real operating current of the motor. Therefore, at a cost of approximately one tenth of the digital signal processor, the programmable high-speed motor torque controller can achieve the functions similar to the digital signal processor. Furthermore, a set of built-in power loop switch can be provided to interrupt the current loop of the motor upon reverse rotation without the requirement of power output, thereby largely reducing the drag force of motor upon reverse rotation.

Abstract: A driving circuit for switches of direct current fan motor is disclosed. The driving circuit includes a plurality of switches, a first control circuit, and a second circuit. The switches are driven by a first pulse width modulation signal and a second pulse width modulation signal, and they are electrically connected with the direct current fan motor in a bridge manner. A third pulse width modulation signal is used to drive the first control circuit connected to at least one of the switches driven by the first pulse width modulation signal. A fourth pulse width modulation signal is used to drive the second control circuit connected to at least one of the switches driven by the second pulse width modulation signal. Especially, either the first pulse width modulation signal or the second pulse width modulation signal is selected as the third pulse width modulation signal or the fourth pulse width modulation signal.

Abstract: Disclosed is an electronic pulse width modulation (PWM) regulator of a low frequency rectangular wave signal serving to control the speed of a direct current motor. The invention aims at simplifying the design of said regulator by eliminating the classical inductive element so that the motor continuously operates as a filter of the output signal provided by the switching component. The invention also aims at preventing noises caused by switching. To this end, subsonic switching frequencies of less than 50 Hz are used.

Abstract: An apparatus for controlling a rotational speed of a motor, coupled to a sensing unit capable of outputting a sensing signal. The apparatus includes a controlling unit, coupled to the sensing unit, for outputting a controlling signal according to the sensing signal and independently of the rotational speed of the motor. The controlling signal is a square wave and has a duty ratio that is determined by the sensing signal. The apparatus also includes a driving unit, coupled to the controlling unit, for outputting a driving signal to a motor rotor according to the duty ratio of the controlling signal. The driving signal also is a square wave. The rotational speed of the motor rotor is determined by the duty ratio of the driving signal.

Abstract: The present invention provides a fan driving circuit using a pulse width modulation (PWM) input signal. Wherein, a signal generator electrically connects to a fan motor and provides power for the fan motor. The signal generator generates a control signal for controlling ON/OFF of the power. Wherein, the signal generator generates a control signal at a buffer period when the fan motor changes phase for controlling phase change. Whereby, by means of the control signal at the buffer period, when phase changes, power-consuming would be reduced. The fan motor can change phase successfully and operate efficiently for power-saving, capacity-improving and cost-reducing.

Abstract: A motor control system for use in heating, ventilation, and air conditioning applications includes a blower, a motor coupled to drive the blower, an inverter coupled to provide energization to the motor, and a controller coupled to the inverter. The controller provides signals to control the output of the inverter in response to received input control signals. Input control signals received by the controller can define first and second operating states. In response to the input control signals defining the first operating state, the controller controls the output of the inverter in accordance with a first volts vs. hertz relationship. In response to the input control signals defining the second operating state, the controller controls the output of the inverter in accordance with a second volts vs. hertz relationship, where the first volts vs. hertz relationship is different than the second volts vs. hertz relationship.

Abstract: Amperage control of a power tool motor is provided by pulse width modulation of current from a power supply. The pulse width modulation may be varied according to the determined motor current and measured power supply voltage. The power supply preferably includes a battery, such a lithium ion or nickel cadmium.

Abstract: When a PWM signal generating unit (10) sets a duty D of a PWM signal based on command signals (10c), the PWM signal generating unit (10) sets a phase difference &phgr; between each of the PWM signals based on a relation formula of &phgr; (degree)=360 (degree)×D (%)/100 (%), and generates and outputs first PWM signals (10a) and second PWM signals (10b) in which the duty is D (%) and the phase difference is &phgr; (degree). The first PWM signals (10a) and the second PWM signals (10b) are respectively supplied to a first load driving circuit (21) and a second load driving circuit (22) to operate a first motor fan (3) and a second motor fan (4) by a PWM control, respectively.

Abstract: This present invention provides a method of fan driving circuit using an adaptive pulse width modulator (PWM) input signal for a signal generator electronically connecting to a fan motor and providing power of the fan motor, the signal generator providing a control signal for controlling ON/OFF of power mentioned. Wherein, the signal generator is a PWM circuit, and this signal generator provides different PWM signal in pursuance of different fan motor loading, enables fan motor stated comprises of adaptive PWM.

Abstract: On end of a reactor (L1) is connected to a positive electrode of a battery (B1) and the other end is connected to a power line via a transistor (Q1) and to the ground via a transistor (Q2). By PWM control of the transistors (Q1, Q2), an arbitrary increased voltage is obtained in the power line. It is possible to obtain an optimal inverter input voltage (power line voltage) according to the motor drive state, thereby increasing efficiency. Thus, it is possible to optimize the inverter input voltage according to the motor drive condition.

Abstract: An electronically commutatable motor having field windings activatable in sequence with a commutation frequency via semiconductor output stages using control signals connectable and disconnectable from a direct voltage supply, the control signals being clocked using pulse width modulation. Noise generation from connection and disconnection of the current applied to field windings is minimized by flattening of the rising and/or falling edges of the current in the field windings. The pulse width ratio increases in the rising edges of the control signals from a low initial value to an operating value assigned to the setpoint as a function of a selected setpoint for the motor speed or output, and, in the falling edges of the control signals, the pulse width ratio starts from the existing operating value and is reduced to a lower final turn-off value as a function of the existing actual value of the speed or the output of the motor.

Abstract: A motor circuit includes a first brush-type motor, a second brush-type motor, a switch, and a pulse width modulation circuit. The first brush-type motor has a first voltage connection and a second voltage connection, the second voltage connection adapted to be coupled to a source of DC voltage. The second brush-type motor has a third voltage connection and a fourth voltage connection, the fourth voltage connection adapted to be coupled to the source of DC voltage. The switch has a control input, a first contact and a second contact, the first contact coupled to the source of DC voltage, and the second contact coupled to the first voltage connection and the third voltage connection. The switch is operable to selectively connect the first contact to the second contact based on a voltage at the control input. The pulse width modulation circuit is operable to generate a pulse width modulated (PWM) signal.

Abstract: The present invention provides a PWM current adjustment apparatus including a triangle wave generator (8) for generating a triangle wave voltage signal, a comparator (9), an FET (10), a power supply (14), a first resistor (11) and a second resistor (12). The triangle wave voltage signal generated by the triangle wave generator and a modulation signal provided by a modulation voltage source (13) are fed to the comparator, an output of the comparator is connected to a gate terminal of the FET, the power supply is connected to a source terminal of the FET through the first resistor, and a drain terminal of the FET outputs a driving current through the second resistor to a load.

Abstract: A system for controlling the rotational speed of a fan, according to a reference clock having a reference frequency, is disclosed. The rotational speed corresponds to a fan rotational speed signal. The fan rotational speed controlling unit compares the reference clock with the fan rotational speed signal, to output a speed controlling signal. The Voltage generating circuit generates a level signal corresponding to the speed controlling signal. The driving unit generates a driving signal to control the rotational speed of the fan according to the level signal. When the fan is assembled with the controlling system, only coils with the same number of turns need to be use to obtain various rated rotational speeds of fans of different specifications by altering the reference frequency of the controlling system. Because coils with different number of turns are not required in stock at the same time, the time cost and the manufacturing cost can be reduced.

Abstract: The invention concerns a method of regulating the current in a direct current machine with which are associated an arrangement for generating a current target value signal, as well as a PWM generator (FIG.

Abstract: A motor control system for use in heating, ventilation, and air conditioning applications including a blower, a motor coupled to drive the blower, an inverter coupled to provide energization to the motor, and a controller coupled to the inverter that provides signals to control the output of the inverter in response to received input control signals

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 motor control system creates a rounding effect on square wave phase currents which results in reduced acoustic noise. The control system includes a voltage source for providing a DC bus current, and an inverter. The inverter has a switching circuit for regulating the DC bus current to a fixed level. The switching circuit also forces consecutive phases of the motor to share the bus current at commutation. Forcing consecutive phases of the motor to share a desired amount of the DC bus current creates a “rounding” effect on the phase currents, which results in reduced acoustic noise. The preferred inverter has a plurality of transistors, and a control module. The control module selectively engages the transistors such that each phase of the motor has a phase turn-on point that occurs before a phase turn-off point of a preceding phase. The control module also pulse width modulates the transistors such that the DC bus current is regulated to the fixed level.

Abstract: A driving apparatus for a stepping motor, especially which, in micro step driving, partly changes a combination of an energization value to each phase of a motor depending upon a rotational direction of the motor and accurately controls a stopping position of a driven object which is driven by the motor.

Abstract: An apparatus for controlling a rotational speed of a motor, coupled to a sensing unit capable of outputting a sensing signal. The apparatus comprises a controlling unit, coupled to the sensing unit, for outputting a controlling signal according to the sensing signal, wherein the controlling signal is a square wave and has a duty ratio that is determined by the sensing signal; and a driving unit, coupled to the controlling unit, for outputting a driving signal to a motor rotor according to the duty ratio of the controlling signal, wherein the driving signal is a square wave, and the rotational speed of the motor rotor is determined by the duty ratio of the driving signal.

Abstract: A method of controlling a DC motor is presented. In a tracking action, an input to the motor is tracked. In a comparing action, the input is compared against a baseline value. In an adjusting action, a usage of the motor is adjusted when the input passes a threshold related to a motor performance parameter. A method of estimating a parameter of an ink carriage moved by a DC motor is also presented. In a tracking step, an input to the motor is tracked. In a comparing action, the input is compared against a baseline value to predict a level of the parameter.

Abstract: A motor control system 10 includes an engine cooling module 14 including a DC motor 12. The system includes a switch 18 constructed and arranged to be controlled by a pulse width modulated (PWM) signal 26. The switch 18 is operatively associated with the DC motor to control current to the DC motor and thus control the speed of the DC motor. A controller 20 is operatively associated with the switch. The controller is constructed and arranged to select periods, of a limited-pool of frequencies each being less than 500 Hz, from a pseudo-random sequence of periods and to send the selected periods to the switch, thereby controlling noise and vibration of the module.

Abstract: A method for maintaining a target speed of a DC motor includes the steps of obtaining a feedback signal from the motor corresponding to motor speed, measuring an actual time for a predetermined number of feedback pulses to be received, comparing the actual measured time with an expected time for the feedback pulses to be received when the rotor shaft is operating at the target speed, and adjusting the controller pulse-width variable signal in response to the compared actual time to the expected time. The drive signal is generated and adjusted by a microprocessor in response to the feedback pulses generated by a feedback element coupled to the motor.

Abstract: A method of controlling a DC motor is presented. In a tracking action, an input to the motor is tracked. In a comparing action, the input is compared against a baseline value. In an adjusting action, a usage of the motor is adjusted when the input passes a threshold related to a motor performance parameter. A method of estimating a parameter of an ink carriage moved by a DC motor is also presented. In a tracking step, an input to the motor is tracked. In a comparing action, the input is compared against a baseline value to predict a level of the parameter.

Abstract: In detecting an output current of a power converter based on a DC current Idc of the power converter, the pulse width of the DC current Idc becomes narrower when the pulse width of a line voltage is narrower, and its detection becomes difficult. A voltage command correction unit 9 according to the present invention corrects voltage commands such that pulse width of a line voltage becomes zero when the pulse width of the line voltage is less than the minimum pulse width, not to output a line pulse, and an error generated by the correction is integrated. This integrated error is added to the line voltage in the next time, and the integrated pulse width of the line voltage is outputted when the pulse width becomes larger than or equal to the minimum pulse width.

Abstract: A system and method of advancing the commutation sequence of a brushless DC motor is provided. The motor having a plurality of coils, each of the coils coupled together at one end to a common center tap and coupled at an opposite end, through a respective coil tap, to both a source voltage and ground via selectively actuateable switches having diodes coupled in parallel therewith. The motor operates in a pulse width modulation (PWM) mode having PWM-on states and PWM-off states. During PWM-off states, a coil tap voltage from the coil tap of a floating phase is provided to a preconditioning circuit. The preconditioning circuit adjusts the floating phase coil tap voltage to compensate for an amount of voltage substantially equal to an amount of voltage by which a voltage at the center tap deviates from zero. The preconditioning circuit further includes sharpening circuitry for amplifying the adjusted floating phase coil tap voltage.

Abstract: A pulse width modulated (PWM) output signal controller circuit is provided for controlling operation of an electronically commutated, direct current (DC) motor. This DC motor may be used for operating cooling fans in sensitive electronic equipment. The controller circuit maintains the motor speed as constant resulting in a minimizing of the motor power consumption and resultant noise generation. Controller circuit output PWM signals are maintained at a constant pulse width even in the presence of variations in the voltage levels supplied to the controller circuit. The controller circuit includes a current pulse sensor circuit that senses changes in current direction in a motor coil. This current pulse sensor's output is input to a monostable multivibrator circuit that produces a chain of constant height output pulses (PWM signals).

Abstract: A DC brushless motor operation speed control method is disclosed. First, a linearly voltage dependent current source is used to charge a capacitor and the terminal voltage of the capacitor is coupled to a linearly voltage dependent base frequency level detector. When the output voltage of the capacitor reaches the base frequency reference voltage, the signal output from the base frequency level detector will make the capacitor discharge, outputting a series of base frequency triangular waves. Under different supply voltages, all the generated base frequency triangular waves have the same cycle time. The base frequency triangular waves are transmitted to a speed control comparator. Through pulse width modulation, the speed control reference voltage adjusts the output pulse width of the comparator and thereby controls the speed of the motor.

Abstract: A controlling device adapted to be used for a heat-dissipating device. The controlling device includes a signal generator electrically connected between the heat-dissipating device and a power source supplying a voltage for the heat-dissipating device, and generating a control signal for switching on/off the power source, and a voltage regulator electrically connected between the heat-dissipating device and the power source and connected in parallel with the signal generator for continuously providing the heat-dissipating device with a basic voltage when the power source is switched off by the control signal so as to prevent that an output signal of an external device electrically connected with the heat-dissipating device is interfered with the control signal.

Abstract: Methods and apparatus for controlling performance of electric motors in a system having two or more electric motors, the motors adapted for being coupled to two or more wheels of an electric vehicle, each of the electric motors having armature and field coils which are independently excited by a source of voltage to generate armature and field currents, the armatures being connected in series to the voltage source include detecting a condition in the system indicating that one of the wheels is slipping, reducing power delivered to one of the motors that is associated with the slipping wheel in response to the detection of the condition, providing power to the one or more motors that are not associated with the slipping wheel after the power delivered to the motor associated with the slipping wheel is reduced, and restoring the power delivered to the one of the motors associated with the slipping wheel in response to a recovery event.

Abstract: PWM controlling means (4) for inputting PWM signals corresponding to PWM target values to electric power supplier (3) in order to servo-controlling DC motor (2) comprises synchronizing control part (41), PWM computing part (50), selecting part of PWM target value (45) and PWM commanding part (46). The synchronizing control part (41) instructs the commencement of the PWM computation, selection of PWM target value and PWM command allotted to some of the infinitesimal intervals obtained by dividing processing term, on which PWM signals regulating the electric power supplied to the motor (2) are allotted, into n equal parts, and terminates one cycle for a series of the process and/or computation predetermined within one processing term. PWM target values corresponding to plural control target values (DP0, DV0, DT0) are computed in parallel so that the servo-control of motor can be operated in quick response to the change of control mode.