Abstract: Described herein are eddy current brakes and associated methods of their use, particularly configurations that have a kinematic relationship with at least two rotational degrees of freedom used to tune operation of the brake or apparatus in which the brake is located.

Abstract: A controller for a power converter and method of operating the same. In one embodiment, the controller includes a peak detector, coupled to a circuit element of the power converter, configured to produce a signal corresponding to a peak current through a circuit element. The controller also includes an adjustable reference circuit responsive to a difference between the signal and a reference signal corresponding to a desired peak current to produce a corrected signal corresponding to the peak current.

Abstract: A current sensing circuit may include a shunt resistance through which current to be sensed travels. A first and a second differential amplifier may each provide an amplified output of the voltage across the shunt resistance. A switching system may deliver a current sensing signal output based on the amplified output of the first differential amplifier when the common mode voltage across the shunt resistance is low and based on the amplified output of the second differential amplifier when the common mode voltage across the shunt resistance is high. The first differential amplifier may provide its lowest output DC offset voltage when the common mode voltage is low, while the second differential amplifier may provide its lowest output DC offset voltage when the common mode voltage is high. The first and second differential amplifiers may both have a low common mode voltage rejection ratio, such as a ratio of less than 40 db at the switching frequency of switches that control the current that is sensed.

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 fan motor speed control circuit includes: a driving circuit configured to drive a fan motor so as to run at a rotation speed corresponding to a drive signal; a comparison circuit configured to output a comparison signal for matching a rotation speed of the fan motor with a target rotation speed, based on a reference signal corresponding to the target rotation speed of the fan motor and a speed signal corresponding to the rotation speed of the fan motor; and a selection circuit configured to output to the driving circuit the drive signal corresponding to one signal out of the reference signal and the comparison signal, the one signal being a signal by which the fan motor is driven at a higher rotation speed.

Abstract: A motor speed control circuit includes: a voltage generating circuit configured to change either a reference voltage corresponding to a target rotation speed of a motor or a speed voltage corresponding to a rotation speed of the motor, according to a temperature, and output the reference voltage and the speed voltage, either one of which is changed; a comparison circuit configured to compare the speed voltage output from the voltage generating circuit with the reference voltage output from the voltage generating circuit; and a driving circuit configured to drive the motor so as to match a level of the speed voltage to a level of the reference voltage, based on a comparison result from the comparison circuit.

Abstract: A fan control system includes a power source, a switch control circuit, a switch control signal delivering unit and a fan circuit module. The power source outputs a nominal power, the switch control circuit electrically connects to the power source, the switch control signal delivering unit electrically connects to the switch control circuit and can send a power control signal to the switch control circuit, and the fan circuit module electrically connects to the switch control circuits. In an initial operation state, the nominal power output from the power source can be reduced to a control power sending to the fan circuit module via the switch control circuit to drive at least one fan within the fan circuit module, and then the power control signal controls the control power after the switch control signal delivering unit sends the power control signal to the switch control circuit.

Abstract: A motor control apparatus includes a fan motor, a hall IC, a first power generator, and a second power generator. The hall IC is coupled with the fan motor for detecting the status of the fan motor, such as rotating or stationary. The first power generator is connected with the hall IC for outputting a first voltage to the hall IC to supply the required power for the hall IC. The second power generator is connected with the fan motor for outputting a second voltage to the fan motor to control the rotation speed of the fan motor.

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: A fan speed control device includes a controller, a switch and a voltage regulator. The controller detects a rotation speed signal of the fan to generate a first driving signal when the rotation speed signal is relatively higher than a predetermined rotation speed signal and generates the first driving signal and a second driving signal when the rotation speed signal is relatively lower than the predetermined rotation speed signal. The switch is electrically connected with the controller and receives the first driving signal. The voltage regulator, which is electrically connected with the controller, the switch and the fan, receives the second driving signal, and controls the rotation speed of the fan in accordance with the first driving signal and the second driving signal.

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

Abstract: A 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 motor controller utilizes sensors to detect the rotational speed and relative position of the motor rotor and generates a voltage vector to maintain the motor current in phase with the EMF before a voltage limit is reached. The approximate actual speed is calculated and position signals are generated by the calculator. The actual speed is compared with a command speed signal and any difference gives rise to an error signal. A proportional integrator receives the error signal and produces a correction signal for a vector rotator corresponding to the desired vertical voltage component necessary to achieve the command speed. After the voltage limit is reached, any further speed increase desired is achieved by rotation of the voltage vector with it's amplitude unchanged.

Abstract: In an optical disc player, as signals are read from and written to an optical disc, the optical disc is rotated by a spindle motor and an optical pickup is moved by a sled motor. These motors are both direct-current motors. The motor control circuit of the invention uses a drive circuit based on the BTL method, and additionally uses a resistor that is connected in series with the direct-current motor between the output terminals of the drive circuit. The voltage drop across the resistor is fed back, as positive feedback, to the drive circuit through a feedback amplifier. Since, when the motor is started up, a high current flows through the motor and thus a large voltage drop occurs across the resistor, a high feedback voltage is obtained and thus a high drive voltage is applied to the motor.

Abstract: In a state of synchronous operation in which a voltage and a frequency of an inverter output are increased in a stage of starting, when it is decided that a voltage difference signal is not at a specified level by a voltage difference signal level deciding section (41) or when a comparison result in a mode comparing section (42) signifies that a position signal and an inverter mode do not have a specified relation, a V/F pattern setting section (44) outputs a voltage command signal for lowering the inverter output voltage to a PWM section (54).

Abstract: Control circuitry for a multi-speed, rotational, direct current motor can include a means to select one of a plurality of discrete circuits to select a desired speed of the motor, each circuit being activated by a separate analog switch which can complete the circuit to select a potentiometer voltage which then becomes a speed reference voltage output; a motor encoder which generates a pulse train proportional to motor speed and is converted to a proportional voltage by means of a frequency-to-voltage converter; an error amplifier, connected to the outputs of the speed reference voltage and the motor speed voltage such that when the speed reference voltage differs from the motor speed voltage, an error signal is produced; a pulse width modifier circuit which is driven by the error signal and which adjusts motor logic outputs so as to adjust the speed of the motor to produce an essentially zero error; a power supply circuit to feed voltage to the controlling circuitry and motor.

Abstract: An improved power supply for converting any of various standard national AC network voltages to low-voltage DC power suitable for driving a 1 or 2-watt device, such as a fan, features a semiconductor control circuit (18, FET 46) which chops each half-wave of a rectified voltage and uses the low-voltage portions to feed charging current pulses to a storage capacitor. The voltage on the capacitor (14) is used by other portions of the circuit to regulate rotation speed of the fan or other consuming device (40) to a value set on a variable resistor. The use of the low-voltage portions of the input signal reduces power losses and increases efficiency.

Abstract: A solid state electronic motor power control circuit for portable paint pumps having a MOSFET power control device and an operational amplifier connected to the MOSFET to selectively operate as a switch driver in a first state and as a linear gain amplifier in a second state. The operational amplifier has a feedback path from the motor to compensate for motor load variations.

Abstract: A shunt element and a voltage detection circuit are connected in parallel across the armature of a universal series motor. At relatively light loads on the motor, the armature speed increases, thereby increasing the back e.m.f. of the armature. The voltage detection circuit causes the shunt element to conduct, and a shunt current flows through the field of the motor, thereby increasing the field and limiting the speed of the motor. Various embodiments are disclosed.

Abstract: A manually operated switch lever moves arm 105 along resistor 113 to generate a "raw" motor speed demand signal which is amplified and inverted by amplifiers 115 and 119 to form a "base line" demand signal.The "raw" demand signal and a motor load signal at the output of amplifier 154 are compared in amplifier 125 to generate an "error" signal. The "error" signal and the "base line" demand signal are summed in amplifier 129 to form a variable reference voltage which is applied to the non-inverting input of comparator 132. The second input to comparator 132 is a triangular shaped wave which is centered about V/2. When the amplitude of the oscillator output wave exceeds the reference voltage, the output of the comparator 132 is low and switch 160 is off. Thus, variations in the D.C. reference voltage at the output of amplifier 129 control the ON-off duty cycle of MOSFET switch 160 to adjust the power applied to motor 106.

Abstract: A device and method for cooling an internal combustion engine is disclosed in which a simple control circuit constructed of relatively inexpensive components enables the rotational speed of an electric motor employed in the cooling device to be controlled in adaptation to various temperature levels of a cooling circuit. The control circuit includes a power semiconductor which is used to drive the electric motor in certain speed ranges associated with predetermined temperature levels. The control circuit also incorporates a bypass circuit that permits the electrical motor to be driven in particular speed ranges without the use of the power semiconductor. Thus, the electric motor can be driven at one hundred percent of its speed capacity by eliminating a voltage drop associated with the power semiconductor.

Abstract: The speed of a DC motor is stabilized to correspond to a reference speed by a motor driving control that is instantaneously responsive to the interval between reference pulses corresponding to the reference speed and actual observed pulses corresponding to the actual motor speed.

Abstract: An electronic control for regulating the operation of a two-speed motor in a heat transfer system such as a heat pump or air conditioner. The control receives high and low demand signals from a thermostat and a motor unit operates at high and low speeds in response to, respectively, high and low speed signals. The control includes an initial timer, high and low speed operators, and a speed change delay. The initial timer detects the occurrence of a demand signal from the thermostat, counts a predetermined period of time, and responsively issues an initial timing completion signal. The high and low speed operators detect the timing completion signal as well as either a high or low thermostat demand signal. One of the operators then responsively issues either a high or low speed signal to the motor unit. The motor unit accordingly operates at a high or low speed. The speed change delay detects the change in a thermostat demand signal from a high to a low state or a low to a high state.