Abstract: An electric vehicle control system controls motor response based upon monitored vehicle characteristics to provide consistent vehicle performance under a variety of conditions for a given accelerator manipulation. In one example, motor temperature is monitored. As the temperature increases, the gain of a power signal provided to the motor is increased to make up for the motor's hindered performance under higher temperature conditions. Other vehicle characteristics that are taken into account include a charge level in a fuel cell or current vehicle speed and engine load.

Abstract: A method for operating an actuating drive for controlling fittings. The actuating drive has an electric motor which is fed from a frequency converter and moves a fitting with a predetermined torque via a self-locking gearbox. In order to protect the actuating drive against unacceptable, destructive heating while maintaining operation in the surrounding process installation when an excess temperature occurs, the temperature of the actuating drive is measured during continuous operation, and the rotation speed of the electric motor is reduced as a function of the measured temperature while maintaining the torque. To this end, the amplitude and the frequency of the output voltage of the frequency converter are reduced in proportion to one another.

Abstract: A thermal control variable speed fan motor comprises a rectifying circuit, a differential amplifier, and a temperature-sensing circuit. The rectifying circuit converts a speed signal detected from the fan into a voltage that is outputted to a negative terminal of the differential amplifier. A positive terminal of the differential amplifier is connected to the temperature-sensing circuit that is connected in series with a power source. The temperature-sensing circuit includes a temperature sensor having a resistance that varies in response to a change in ambient temperature. When ambient temperature rises, the drive voltage outputted by the differential amplifier increases and the fan speed increases. When ambient temperature reduces, the drive voltage decreases and the fan speed decreases, thereby changing the fan speed linearly by thermal control.

Abstract: A high-efficiency, automatic detecting, and self-adjustable temperature controlled air flow device, more particularly a computer power supply having dual adjustment temperature controlled air flow device, includes a primary fan mounted at a front end of a power supply of a computer, and a secondary fan mounted at the other end. One side of the primary fan is provided with an adjustment knob to allow the user to adjust rotational speed. The secondary fan is controlled by an environmental temperature detecting circuit inside the power supply. The device can automatically adjust, detect, and provide high-efficiency heat dissipation effects.

Abstract: A fan motor having a two-step speed control includes a buffer circuit, a control voltage terminal, and a fan. The buffer circuit is mounted between a voltage source and a source terminal of the fan. The buffer circuit includes a resistor and a transistor. The control voltage terminal is connected to a transistor of the buffer circuit to control conduction or non-conduction of the transistor, thereby changing the voltage of the source terminal of the fan. The varying voltage waveforms are smooth linear waveforms such that rotating speed of the fan is increased or decreased gradually during switching between a low-speed operation mode and a high-speed operation speed.

Abstract: A motor controller improves reliability and enables stable and high-accuracy control by detecting a current value running through the motor detected by current detectors by preventing changes in ambient environment, particularly the influence of temperature variations. The arithmetic and control unit of the motor controller has a storage unit for storing current detection characteristic compensation data for compensating for fluctuations in the characteristics of the current detectors, a current value computing device for computing current values by correcting detection currents from the current detectors, and a device for computing and generating drive signals for controlling the switching of the power elements based on the computed current values.

Abstract: An apparatus invention relates to an apparatus and method for monitoring an interior space which is closed off by a locked and/or manually non-unlockable door, flap, sliding sunroof or the like, for example a passenger compartment or luggage compartment of a motor vehicle, with respect to living entities enclosed therein and the quality of their living environment, having a control circuit and sensor evaluation arrangements connected thereto, which arrangements each interact with at least one sensor, a first sensor evaluation arrangement outputting a first signal to the control circuit if there are living entities in the interior space, and a second sensor evaluation arrangement outputting a second signal to the control circuit if the living environment changes in the direction of life- and/or health-threatening states, at least one actuator connected to the control circuit acting on a motor-actuatable closure of the door, flap, sliding sunroof or the like, which is activated by the control circuit for the pu

Abstract: The present invention provides a control apparatus for an electric vehicle, capable of reducing the switching loss while restricting the surge voltage generated in the IGBT elements constituting a driving inverter of a motor for moving the electric vehicle to a predetermined voltage below an allowable surge withstand voltage. The control device of the electric vehicle comprises an IGBT temperature detecting device 11 for detecting the temperature of the IGBT elements, a gate resistance calculation device for detecting the resistance of the gate resistor so as to restrict the voltage including the surge voltage, which is applied to the elements, to a predetermined voltage below the allowable surge withstand voltage of the elements using an output command current, a battery voltage, and/or the detected temperature by the IGBT temperature detecting device 11 as parameters.

Abstract: A fan linear speed controller is disclosed, which controls the rotation speed of a fan by an external fan control voltage. The fan linear speed controller includes a temperature sensor unit, a linear speed control unit and a fault detection unit. The temperature sensor unit has a thermistor for detecting the ambient temperature of the fan to generate a thermally sensitive voltage. The linear speed control unit receives the external fan control voltage and the thermally sensitive voltage to generate an output voltage for driving the fan. The output voltage is proportional to the fan control voltage when the thermally sensitive voltage is lower than a preset threshold voltage and the fan control voltage is higher than a preset reference voltage. The fault detection unit receives the thermally sensitive voltage and a rotation speed signal generated by the fan to selectively produce a fault signal indicating that the rotation of the fan is abnormal or the ambient temperature of the fan is too high.

Abstract: A circuit to bypass the Zener diodes in the flyback circuit of a DC brush motor actuator which uses a voltage sensitive device to detect when the power to the motor is de-activated to control a switch that short circuits the Zener diodes.

Abstract: A starting device for electric motors which is designed to be fitted to compressor motors or the like, and includes a PTC resistor in series with a relay inserted between the line and the motor start winding.

Abstract: A sensor for facilitating the measurement of temperature and magnetic field is described. The sensor comprises an optical cable having a distal end encompassed in a sheath of giant magnetoresistive material. Temperature changes alter the spectrum emissivity of the giant magnetoresistive material. Magnetic field changes alter the spectrum changes that occur from distorting the optical fiber that occur when the giant magnetoresistive material distorts the optical fiber.

Abstract: When air passing through a condenser and a radiator passes through a cooling fan in a state where a driving circuit controls a voltage applied to a motor to be constant in accordance with a motor application voltage instructed by a control signal Sa, a motor current Im decreases. A comparator compares the motor current Im with a reference current set on the basis of a motor voltage Vm. When the motor current Im decreases to a value equal to or lower than the reference current, a switching circuit is switched to select an output signal of an operational amplifier. The operational amplifier performs a feedback control so that the motor voltage Vm coincides with a minimum application voltage VL.

Abstract: Apparatus and method for reducing fan noise in a personal computer having at least one fan with a direct current motor. The fan is disposed within and ventilates a zone. Operative voltage is applied to the motor through a controller from a power supply. Thermo-sensors in the zone measure the temperature in the zone. A table coupled to the controller lists for each temperature value an optimum rotational rate for the fan, the optimal value being the minimal value of rotation rate for the fan to provide a sufficient ventilating of the zone at this corresponding temperature. The thermo-sensor when actual temperature in the zone is changed during operation, inputs this condition to the controller, which modifies the voltage, applied to the motor, to provide the assigned optimal rotation rate.

Abstract: A vehicle electric assist steering system (10) includes a switching circuit (56) for providing electrical power to an electric motor (52) of the vehicle steering system. The switching circuit (56) has a temperature condition. A temperature sensor (69) is coupled with the switching circuit (56) for providing an output signal (71) having a value indicative of the temperature condition of the switching circuit (56). A stall detector (70) is responsive to the output signal (71). The stall detector (70) is operable to reduce power to the electric motor to different level during a stall condition based on the sensed temperature condition of the switching circuit (56).

Abstract: A start-up switch 50 for an electric motor 1 comprises a resistive element (54) which is so constituted as to be connectable to an electric current path (15) and which has such a characteristic that its resistance value increases by the heat generated by electric current that flows through the electric current path (15) and a thermostatic switch (60) which is connected in series with the resistive element (54). The thermostatic switch (60) has an actuation member (60) which is responsive to temperature so that upon reaching a preselected temperature, said member moves from a closed current path position to an open current path position. The thermostatic switch (60) is positioned to be in direct heat transfer relationship with the resistive element (54) so that the member will (66) rise in temperature as the resistive element (54) rises in temperature.

Abstract: A regulator for heating and air-conditioning appliances in motor vehicles, having a suction fan which is driven by an electrically commutated DC motor and in whose induction air flow a temperature measurement sensor is arranged. A disturbance in motor running which may lead to an incorrect temperature measurement is detected at an early stage by providing measurement means which, in two time intervals, determine measurements that are proportional to the frequency of the motor voltage, and compare these measurements with one another.

Abstract: A controller of an electric power steering system corrects a motor current command value by using a temperature of a motor, and compensates a variation in a motor current characteristic in accordance with a variation in the temperature. The controller includes a torque sensor for detecting a steering torque of a steering wheel; a motor for supplying a steering assist torque to a steering shaft integrally provided with the steering wheel; and a control unit for driving the motor in accordance with a magnitude of the steering torque. The control unit corrects a motor current command value in accordance with a temperature of the motor, and controls a motor current in accordance with the corrected motor current command value.

Abstract: A drive unit includes an electric motor as a power source, and a simplified coolant circuit for cooling the electric motor. The drive unit further includes, in the drive unit case, a circulation passage L for coolant for cooling the motor M. A circulation passage F for a second coolant is provided separate from the circulation passage L for coolant. A heat exchange portion C within the circulation passage L for the first coolant is provided in the drive unit case for heat exchange with the second coolant in the circulation passage F, and the first coolant for cooling the electric motor is cooled by heat transfer to the second coolant in that heat exchange portion C. Accordingly, the coolant circuit in the drive unit case is simplified.

Abstract: A DC fan using a power supply and sleep/non-sleep-mode signals for controlling the rotating speed thereof includes a DC brushless motor and a power sleep-mode control unit. The DC brushless motor serves as a driving source of the DC fan. The power sleep-mode control unit is electrically connected to the DC brushless motor for receiving the power supply and the sleep/non-sleep-mode signals, thereby outputting an operating power supply and controlling the rotating speed of the DC brushless motor.

Abstract: A driving controlling apparatus of a hood motor, including: hood motor means rotatably driven for ventilating the inner portion of a system; main controlling means for generating control signals for controlling the operation of the hood motor; sub-controlling means for controlling the driving of the hood motor by sensing temperature changes in the system; and driving circuit means for controlling the driving of the hood motor in accordance with the control signal of the main controlling means and the driving controlling of the sub-controlling means.

Abstract: Current correction control is carried out by control process of a control circuit 13 that temperatures of the electromagnetic relays 18a and 18b are assessed one by one based on the detection temperature by the temperature sensor 18c, when the temperature assessed value rises over the predetermined value, the upper limit of the target current value of the motor 11 is decreased.

Abstract: A drive circuit for a speed automatically adjusted fan comprises an actuating circuit, a temperature control circuit and a current control circuit. The actuating circuit has a Hall IC to control two transistors in a state of connecting and in a state of disconnecting sequentially so as to alternately magnetize two coils connecting to the two transistors respectively and then to rotate the fan. The temperature control circuit has a heat sensitive resistance to sense the ambient temperature and varies resistance value thereof accordingly such that the magnitude of the current passing through. The current flowing through the current control circuit is fed back to the actuating circuit so that the speed of the fan can be changed with respect to the magnitude of the current to meet the purpose of speed automatically adjusted for the fan.

Abstract: A motor starter thermal-compensation control is disclosed in which an ambient temperature sensor is positioned to sense ambient temperature and provide an ambient temperature signal in a motor starter. Additional temperature sensors are mounted in thermal communication with each bus bar in a motor starter and to monitor the temperature of each pole. A microprocessor is connected to each of the temperature sensors and periodically receives the temperature signals to monitor change in operating temperature of the motor starter. The control adjusts the output of the motor starter based on the change in the operating temperature so as to maintain a constant output as the ambient temperature increases, or the internal resistance of the device increases with temperature increase. In order to adjust the output, the system increases the FLA ampacity to compensate for the temperature increase.

Abstract: A motor starter control is disclosed in which an ambient temperature sensor is positioned to sense ambient temperature and pole temperature sensors are used to sense each pole temperature in a motor starter. A microprocessor is connected to periodically receive the temperature signals and monitor change in operating temperature of a motor starter system. The microprocessor models cool down characteristics of the motor starter system and compares currently acquired ambient and pole temperature signals to the modeled cool down characteristics and determines whether the motor starter system is cooled to a safe start temperature. The control ensures that a maximum number of starts per hour is not exceeded and prevents attempted starts that not only waste energy, but further prolong time to a successful start.

Abstract: A method (10, 30) for actively controlling the temperature (tmotor) of an electric machine operating under torque (T*), speed and/or position control. A controlled output (T*), i.e. torque command, voltage, current or power, is adjusted such that the temperature of the electric machine does not exceed a predetermined reference limit (tref). The method (10, 30) of the present invention performs proportional-integral control (14) to reduce the commanded output (T*) to the motor and thereby prevent the steady-state motor temperature (tmotor) from increasing beyond the predetermined limit (tref). In one embodiment of the method (10), an error term (e) is filtered through a negative pass filter (12) before being combined with an optional decay term (&egr;decay) in a proportional-integral controller (14). A positive pass filter (20) and a negative pass filter (22) provide outputs that are summed and provide an adjusted output command (Tlimited) based upon predetermined relationship.

Abstract: A temperature controlled radiating fan comprises a temperature detector, a control circuit, a power control circuit, a regulator, a loading circuit, and a driving circuit. The temperature detector is connected to the control circuit. The output of the control circuit is connected to the power control circuit. The output of the power control circuit is connected to the loading circuit. The output of the loading circuit is connected to the driving circuit. The power control circuit is connected to the regulator. Thereby, the rotary speed of the fan motor is varied according to a voltage variation, so that the characteristic of the rotary speed of the fan motor is linearly changed.

Abstract: In order to control the operating voltage of a fan in electrical equipment, the temperature of an output diode (D) of an output circuit of the power supply of the electrical equipment is monitored. The operating voltage of the fan is controlled as a function of the component temperature of this physical element such that up to a limit temperature, which is in the region of the maximum permissible component temperature of a physical element which absolutely becomes the hottest, the operating voltage of the fan is regulated at a constant, minimum level. The operating voltage is then regulated to rise continuously and rapidly up to a maximum operating voltage at which, although the component temperature of the physical element which absolutely becomes the hottest is still above the limit temperature, it is below the maximum permissible component temperature of this physical element, however.

Abstract: An electronic device for modeling the temperature of a motor by utilizing signals output from current sensors placed on motor power supply phases. Signals from the current sensors are sent to an interface that outputs a voltage which is an image of a summation a ratio of the motor currents sensed by each of the current sensors to a corresponding adjustment current for each of the phases. A calculation circuit utilizes the voltage as an input and outputs a charging current wave stream, the amplitude and the duration of the charging current being proportional to the summation the ratio. An RC type modeling circuit is provided to receive the charging current wave stream and to model the thermal state of the motor based on the charging current wave stream.

Abstract: A spring return rotary actuator incorporating a DC brush commutated electric motor and a pulse width modulation drive circuit which reduces the voltage at which current is supplied to the motor once a rotation sensor senses that the actuator output shaft has stalled. The drive circuit also includes a temperature responsive feature which increases the voltage at which current is supplied to the motor in the event a sensed temperature exceeds a temperature limit.

Abstract: In a method for braking an electric drive motor, especially a drive motor for driving a grooved drum of a winding head of a bobbin winding machine which motor is loaded for braking in a direction opposite to a rated nominal current with a braking current, the instantaneous thermal load of the drive motor is detected and the strength of the brake current is selected as a function of this thermal load of the drive motor.

Abstract: A load control system includes a driving circuit for electrically controlling a blower motor, and a control circuit for generating a control signal for the motor. The driving circuit is directly connected to an electrical power source, and the control signal from the control circuit is input into the driving circuit through a signal input line. The control signal from the control circuit is a duty signal in which a duty ratio becomes 100% when the signal input line is ground short-circuited. In the load control system, a comparison circuit determines a ground short-circuited state of the signal input line when the duty ratio is increased to a value proximate to 100%, and the motor is automatically stopped based on output from the comparison circuit when the signal input line is ground short-circuited. Thus, the load control system can prevent full-load operation of the motor due to the ground short-circuit of the signal input line, even the driving circuit is directly connected to the electrical power source.

Abstract: A semiconductor integrated circuit device 1 for use in a disk drive has a temperature detection section 9 that detects the temperature inside the semiconductor integrated circuit device 1 to switch a signal TSD between high and low levels when a predetermined temperature is reached, and a delay circuit 11 that receives this signal TSD and a clock from a control section 10 to output signals TSD1 and TSD2.

Abstract: Thermal management within an electrically powered systems requires monitoring, from time-to-time, both electrical power consumption and temperature within the system. The power consumption and temperature data thus obtained permits developing over time a thermal model for the system. After a thermal model for the system has been thus developed, the model together with the presently sensed electrical power consumption, and the system temperature are used to predict a thermal trend for the system. The predicted thermal trend thus obtained for the system is then used in effecting a temperature control strategy within the electrically powered system.

Abstract: A speed control device for a cooling fan and a method of control thereof are disclosed, in which temperature and noise among other factors are taken into consideration, whereby changes to the voltage/current of power supply provided to the cooling fan are used to adjust the speed of the cooling fan. The speed is reduced as much as possible within the permissible range of system temperature to minimize the noise generated from the cooling fan. When the temperature exceeds the permissible range, the speed of the cooling fan is accelerated to reduce system temperature.

Abstract: An electronic device has a heat producing component thermally coupled to a heat dissipation structure. The electronic device further has control circuitry connected to a temperature sensor that senses the component temperature of the heat producing component. The control circuit is further connected to a cooling device also thermally coupled to the heat dissipation structure. The control circuit varies the cooling rate in a manner that cancels out a lag time which occurs during a change from a steady state condition of the component temperature. The cooling rate of the cooling device is varied by the control circuit in proportion to variation in sensed component temperature from the temperature sensor.

Abstract: A fan speed control system for an electronic equipment enclosure comprises means for determining temperature at a plurality of locations within the enclosure, means for determining operating parameters for the fan control system, means for setting operating speed of at least one cooling fan, and means for exchanging information signals relating to fan speed control system operation with an external controller. A method is also provided for controlling fan speed for an electronic equipment enclosure comprising the steps of determining temperature at a plurality of locations within the enclosure, determining operating parameters for the fan control system, setting operating speed of at least one cooling fan, and exchanging information signals relating to fan speed control system operation with an external controller.

Abstract: Disclosed is a method for controlling a temperature of an electric motor. According to the present invention, the method for controlling the temperature of the electric motor includes the steps of setting a present temperature of the electric motor as an initial value, comparing the present temperature with a lower limit temperature when the multifunctional apparatus receives an order to perform a printing, performing the printing if the present temperature is lower than the lower limit temperature at the comparing step, converting a time for printing into an increased value of the temperature at the performing step and resetting the increased value of the temperature as the present temperature, and delaying the printing for a predetermined time if the present temperature is higher than the lower limit temperature at the comparing step.

Abstract: An interface apparatus for fan monitoring and control includes a current source amplifier that generates a programmable current in response to its input voltages. Associated with an output capacitor, which is able to reduce noise, the programmable current drives the fan at a desired speed. The rotating fan induces a ripple signal in the output capacitor, which is fed to a band-pass amplifier to produce a tachometer pulse. Through a buffer amplifier, an input control signal combined with a thermal sensor signal has direct control over the current source amplifier. Alternatively, a PWM circuit having a comparator, a ramp oscillator and the output of the buffer amplifier drives the current source amplifier in switching mode. Since the ramp oscillator can be synchronized by the input, both analog and pulse signals can function as the input control signals.

Abstract: Temperature sensors A, B, and C are arranged near a CPU, HDD, and PC card controller, and monitor changes in temperature of these devices. When a given temperature sensor detects that the temperature of the corresponding device has exceeded a threshold temperature, the device to be cooled is determined by identifying that temperature sensor, and cooling is done at power suited to the temperature characteristics of the determined device.

Abstract: The circuit configuration is used to drive an electrical drive unit. The circuit has a voltage source and a control circuit for voltage commutation connected between the voltage source and the electrical drive unit. In addition, the circuit includes a temperature evaluation circuit that monitors the temperature of the control circuit. The temperature evaluation circuit uses the motor current of the electrical drive unit to determine the housing temperature of the power switch which has the greatest load.

Abstract: A temperature sensor is located close to each of a plurality of switching elements. Each of the elements opens and closes a current supplying line from a power supply to a three phase SR motor. A generating circuit of a instruction value for the driving current of the motor generates a target value (It) of the driving current so as to achieve a requested power of the motor and an allowable value of the driving current on the basis of the highest temperature sensed by the temperature sensors. The circuit outputs the target value as an instruction value of the driving current when the target value is smaller than the allowable value and outputs the allowable value as an instruction value of the driving current when the target value is greater than the allowable value.

Abstract: A movable barrier operator includes a wall control switch module having a learn switch thereon. The switch module is connectable to a control unit positioned in a head of a garage movable barrier operator. The head unit also contains an electric motor which is connected to a transmission for opening and closing a movable barrier such as a garage door. The switch module includes a plurality of switches coupled to capacitors which, when closed, have varying charge and discharge times to enable which switch has been closed. The control unit includes an automatic force incrementing system for adjusting the maximal opening and closing force to be placed upon the movable barrier during a learn operation. Likewise, end of travel limits can also be set during a learn operation upon installation of the unit.

Abstract: A method and integrated circuit for providing drive signals to a polyphase dc motor. The integrated circuit is fabricated on a semiconductor substrate for providing drive signals to a polyphase dc motor. The circuit includes a coil drive circuit for connection to drive coils of the motor to selectively supply drive currents thereto in a predetermined sequence. A sequencer circuit commutatively selects the drive coils to which the drive currents are selectively supplied, and a motor, speed controlling circuit controls the speed of the motor by controlling the speed of commutation. A temperature sensing element, such as a diode, is fabricated in the substrate to indicate the temperature of the substrate, and a temperature measuring circuit is connected to the temperature sensing element and to the motor speed controlling circuit to operate the motor speed controlling circuit to slow the speed of the motor when the temperature of the substrate exceeds a first predetermined temperature.

Abstract: Backward movement of a heavy motorcycle is assisted by a starter motor for cranking an engine of the motorcycle. A backward drive control system includes a pulse width modulation circuit for supplying operating current to the starter motor in a controlled manner and a device for estimating operating temperature of the starter motor based on the current supplied to the starter motor. When the estimated temperature reaches a predetermined maximum temperature, the operation of the starter motor is compulsorily stopped and prohibited for a certain period or until the starter motor is cooled down to a certain temperature level. Overheating of the starter motor is effectively prevented without using a temperature sensor for measuring the operating temperature.Moreover, chattering of the starter motor does not occur because its operation is prohibited for a certain period after the starter motor is once compulsorily stopped.

Abstract: A protective device suitable for being placed in the power supply circuit of an electric motor, having at least one anti-interference coil (20, 30) for the motor, and a thermal switch (10) thermally coupled to coil (20, 30) and capable of opening the power supply circuit when the coil temperature which it detects reaches a predetermined value, representative of the maximum temperature threshold allowed within the motor. Advantageously, the device also has an electric heating element, thermally coupled to the switch and capable of constituting a main current path between the two input terminals of a four-terminal network consisting of the protective device, when the power supply circuit is open, and capable of holding this circuit open in order to limit the opening-closing cycles of the switch, the invention also pertains to the corresponding process and to a drive device containing a motor and of said protective device mounted on the motor, outside of it.

Abstract: Rotor temperature in induction motors is estimated without the need for any direct temperature sensors, by using only computer calculations based on data readily available in the motor control center. Thus for any given motor, it is generally possible to predetermine a relationship between rotor temperature and rotor resistance, so that by determining rotor resistance, rotor temperature can be calculated. Rotor resistance, in turn, can be calculated from measured information relating motor slip and motor torque. Any of several methods can be employed for determining torque and slip. Temperature estimation can be obtained by use of equivalent circuit methods, and additional relationships can be obtained from a simplified equivalent circuit.

Abstract: Disclosed herein is a monolithic fan controller circuit which provides the following features: a special start-up routine for the fan; a fan fault detector; a thermal fault detector; an automatic speed controller; a minimum speed controller; a routine for attempting to clear temporary fan faults; and a controllable drive signal frequency. A start-up control circuit provides an initial high duty-cycle kick to the fan in order to initiate the rotation of the fan. A temperature sensor, which may be external or internal to the monolithic fan controller, supplies a signal which is proportional to measured temperature. This signal is used to control the output pulse width of a pulse-width modulator (PWM) or control the frequency of a pulse frequency modulator (PFM). The PWM or PFM output signal regulates the speed of the brushless (or brush) DC fan motor. In a preferred embodiment, the monolithic fan controller has 8 pins.

Abstract: An electrical control system for an induction motor for achieving optimum efficiency at both full and partial loads at markedly reduced electrical components costs while maximizing reliability over the range of load, and for achieving a two step motor power output in a greatly simplified manner, the circuit having an electrical induction motor adapted for connection to line electrical power at maximum motor operating frequency, and to a second source of electrical power at approximately one half of the maximum operating frequency, wherein an electrical switch is provided for selectively connecting each power source to the motor, wherein the second source is a generator for producing a reduced frequency sine wave form.

Abstract: A method for controlling the operation of a brushless DC fan for cooling heat generating components of a system is provided. The method includes providing a system temperature signal indicative of a system temperature and providing an intelligent shutdown enable signal. The system temperature signal is compared with a shutdown temperature signal if the intelligent shutdown enable signal has a first value. The shutdown temperature signal is representative of a shutdown temperature value. The fan is operated at a generally temperature proportional speed after comparing the system temperature signal with the shutdown temperature signal if the system temperature as indicated by the system temperature signal is greater than the shutdown temperature value as indicated by the shutdown temperature signal.