Abstract: An electronically commutated motor (ECM) includes windings, a power switch, an infrared transceiver and an electromagnetic shield. The power switch is configured to provide pulse width modulated (PWM) power signals to the windings and to generate a substantial level of electromagnetic noises at PWM frequencies during its switching operation. The infrared transceiver is configured to communicate with an external device using infrared signals and convert electrical signals from and to infrared signals that carry data. The electromagnetic shield is configured to substantially shield the infrared transceiver from the electromagnetic noises of PWM frequencies from the power switch.

Abstract: An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of the phase paths between the solid-state switching device and the power input, a current sensor on one of the phase paths, a processor communicatively coupled to the voltage sensor, the current sensor, and the solid state switching device; and a memory coupled to the processor. The processor may be configured to calculate a motor parameter based on a signal from the voltage sensor and a signal from the current sensor and store the calculated motor parameter in memory.

Abstract: An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of the phase paths between the solid-state switching device and the power output, a current sensor on one of the phase paths, a processor communicatively coupled to the voltage sensor, the current sensor, and the solid state switching device; and a memory coupled to the processor. The processor may be configured to calculate a motor parameter based on a signal from the voltage sensor and a signal from the current sensor and store the calculated motor parameter in memory.

Abstract: An apparatus and method used to charge a self powered gate driver system. The apparatus may include a current loop for inducing a current in a coil. A bridge rectifier may rectify the current induced in the coil and charge a capacitor used to power a driver in a self powered gate driver system. The current loop and coil may be separated by a dielectric to prevent current from passing between the self powered gate driver system and the current loop. The current loop may couple to a line voltage transformer to drive an alternating current through the current loop. In certain embodiments, a single current loop and transformer may charge a plurality of self powered gate driver systems.

Abstract: A semiconductor device includes an anode electrode in Schottky contact with an n-type drift layer formed in an SiC substrate and a JTE region formed outside the anode electrode. The JTE region is made up of a first p-type zone formed in an upper portion of the drift layer under an edge of the anode electrode and a second p-type zone formed outside the first p-type zone having a lower surface impurity concentration than the first p-type zone. The second p-type zone is provided 15 ?m or more outwardly away from the edge of the anode electrode. The surface impurity concentration of the first p-type zone ranges from 1.8×1013 to 4×1013 cm?2, and that of the second p-type zone ranges from 1×1013 to 2.5×1013 cm?2.

Abstract: A circuit for driving an appliance for treating laundry, includes a motor circuit having an AC motor, and a door-locking circuit. The motor circuit and the door-locking circuit may be driven by a single common electronic switching element.

Abstract: An induction motor controller that may include three phase paths leading from a power input to a power output, a solid-state switching device interposed between the power input and the power output on each of the three phase paths, a voltage sensor coupled to two of the phase paths between the solid-state switching device and the power output, a current sensor on one of the phase paths, a processor communicatively coupled to the voltage sensor, the current sensor, and the solid state switching device; and a memory coupled to the processor. The processor may be configured to calculate a motor parameter based on a signal from the voltage sensor and a signal from the current sensor and store the calculated motor parameter in memory.

Abstract: Motor drives, motor speed controllers, motor speed estimation systems, and methods are presented for controlling motor speed and for estimating motor speed, in which a speed estimate controller provides a rotor speed estimate based on a first error term from a torque-based MRAS component for a first range of motor speeds and based on a second error term from a rotor flux-based MRAS component for a second range of speeds.

Abstract: Motor drives, motor speed controllers, motor speed estimation systems, and methods are presented for controlling motor startup speed and for estimating motor speed during startup, in which a speed estimate controller provides a rotor speed estimate based on a first error term from a torque-based MRAS component for a first range of motor speeds and based on a second error term from a rotor flux-based MRAS component for a second range of speeds.

Abstract: A system and method determine the parameters of a field of a DC motor. The method comprises obtaining parameters of the DC motor; and performing an iterative processing loop, the iterative processing loop being performed n times. The iterative processing loop includes regulating field current based on the parameters of the DC motor, and calculating a field resistance from a field voltage and the field current measured during the regulating of the field current; operating in a closed loop mode to determine a first field firing angle and a second field firing angle; operating in an open loop mode to determine a first time constant and a second time constant based on applying the first field firing angle and the second field firing angle; and determining at least one parameter of the field of the DC motor based on the first time constant, the second time constant, and the calculated field resistance.

Abstract: An apparatus for and method of controlling the circulating fan of a gas appliance. The circulating fan is powered by an alternating current electric motor. An electronic circuit, powered by the heat of the gas appliance, determines the rotational speed of the electric motor by controlling the effective duty cycle of the alternating current source coupled to the electric motor.

Abstract: A method and system for compensating for voltage notches in phase locked loop (PLL) control devices. A bridge firing controller receives signals representative of two of the line to line voltages received by the bridge. The controller includes a PLL synchronizing tool which receives the line to line voltage signals and generates a synchronizing phase error signal for aligning the phases of the two input signals. The controller, for a predetermined period following bridge firing, determines whether a voltage notch has occurred. If so, the controller substitutes model control signals for actual control signals so as to reduce the effect of the notch on the generated phase error signal used for synchronization. If not, the controller continues to use the actual control signals to generate the phase error signal. Once the predetermined period has expired, the controller utilizes the actual control signals to generate the phase error signal.

Abstract: A method and arrangement for controlling the output of electrical consumers connected to ac line voltage, especially of electric motors and the like, in which the output is changed by changing the phase control of the electric alternating magnitude supplied to the consumer. The extent of the firing angle determining the extent of the phase control is varied toward larger or smaller values around the given reference value of the firing angle, which reference value corresponds to the desired power consumption, so that asymmetry of the firing angle is produced with respect to time between two successive full waves, whereby odd-numbered harmonics are sharply reduced as even-numbered harmonics slowly increase.

Abstract: Methods and apparatus for controlling energization of an appliance motor are described. The apparatus, in one embodiment, may include a condition responsive switch secured within an appliance motor casing to control the energization of the appliance motor windings. In one mode of operation, the condition responsive switch substantially prevents energization of the motor windings if at least one attachment has not been substantially properly secured to the appliance, and the switch substantially properly secured to the appliance.

Abstract: A power tool has a variable speed control circuit that comprises a user switch, a motor and a thyristor connected in series between a pair of power supply terminals. A manually variable resistor is connected between a first electrode of the thyristor and a circuit node. A capacitor is coupled between the circuit node and the second thyristor electrode. A bleed-off resistor is connected between second thyristor electrode and the circuit node to provide a path for discharging the capacitor when the user switch is open. A semiconductor trigger device, such as a diac or silicon trigger switch, couples the circuit node to the thyristor gate electrode. The circuit operation ensures that the capacitor charges from substantially the same voltage level at the start of each half-cycle during which the thyristor is to be turned on.

Abstract: A system and method for controlling power transfer between an internal combustion driven electrical power generator and a direct current (DC) motor. In one form, the invention includes control of a power inverter in a manner to restrict current through a winding of the generator to a predetermined polarity. The inverter includes a plurality of gate controlled switching devices which are selectively energized to allow current to free wheel through the motor during at least some portion of each alternating voltage cycle of the generator. In another form, a plurality of resistors are connected in series with an inverter and a DC motor with each resistor including a switching device for bypassing current around the associated resistor. In this form, resistors can be selectively inserted into the series path during electrical braking so that a maximum amount of electrical energy can be transferred to the generator through the inverter without exceeding the voltage limits of the inverter during high speed braking.

Abstract: A universal diac is provided for implementation in controlling an SCR in a motor speed control circuit. The diac is provided with dissimilar interconnections between the emitters and base, such that the device operates as a standard diac in one mode of operation, and as a zener diode in an opposite mode of operation. The zener characteristics are achieved by the implementation of a shorted base configuration.

Abstract: An apparatus and method for controlling a motor used for rotating a drill stem is disclosed. Silicon control rectifier based system regulates the power to the motor. A control unit coupled to the SCR regulator and the motor monitors the motor input current, voltage and speed levels. If during operation the motor current exceeds a predetermined value and at the same time the motor voltage or speed falls below a predetermined value, the control unit activates an alarm condition and causes the SCR regulator to controllably ramp down the current supply to the motor and then reduces the motor speed reference.

Abstract: A three-phase electric motor is coupled to each phase line of an electric source by pairs of SCR's coupled in inverse parallel relationship. One of the SCR's in each pair is triggered by a signal from a conventional motor control circuit which regulates the phase angle at which the SCR turns on. The other SCR in each pair is an optically triggered device which is activated by light emitted from an LED in one of the legs of a three-phase rectifier bridge in the control circuit power supply. When the LED within a leg of the power supply is forward biased so as to conduct current, it emits light which triggers a correspondingly biased opto-SCR to supply current to the motor. A separate transistor is connected in parallel across each of the LED's to provide a current shunt path when the motor is to be turned off so that the LED does not emit light and trigger the SCR.

Abstract: A motor controller for use on a treadmill to prohibit the treadmill from operating at a high speed immediately upon energization. The controller uses solid state circuitry in a motor speed circuit with a speed setting potentiometer set by the user. The system is adapted so as upon energization a minimum speed is initially achieved. The results are obtained with the interaction of a buffer circuit, solid state circuitry, and an SCR motor speed control circuit.

Abstract: An apparatus for controlling a motor comprises an oscillator for providing a source of periodic signals, and a divider for converting the oscillator output into desired motor rotation frequency signals. A tachometer generates actual motor rotation frequency signals and a comparator compares the actual and desired motor rotation frequency signals and generates a rotation frequency error signal. The tachometer and the divider are coupled to the comparator. An SCR bridge controls motor rotation frequency. The comparator is coupled to the SCR bridge. An AND gate coupled to the source of periodic signals provides a counting gate during which periodic signals from any suitable source are to be counted and a counter coupled to the AND gate counts the periodic signals. A display displays the number of such periodic signals counted during the counting gate.

Abstract: A circuit for controlling the speed of a DC motor provides delay and sampling means in the feedback loop to delay the triggering of the SCRs driving the DC motor and measured the motor armature voltage during the period of the delay, thereby eliminating errors in the armature motor voltage caused by the SCR motor excitation.Alternatively, the current to the motor is measured to generate a pulse output for initiating an interval during which the measured armature voltage is sampled and transmitted to a summator for generating an error signal controlling application of power to the DC motor whereupon the aforesaid interval is terminated upon receiving a pulse indicative of power application to the DC motor.

Abstract: A control circuit for a forced-air heating system comprises a silicon diode that is positionable in thermally-conductive relationship with the interior space of a furnace plenum. A current source supplies current to the silicon diode, and the potential drop across the silicon diode is sensed. The operating speed of the blower is controlled in response to the voltage drop across the silicon diode in a manner such that when the temperature in the plenum is below a first level, the blower is not driven; when the temperature reaches the first level, the blower is driven at a first speed; and when the temperature reaches a second level, which is higher than the first level, the blower is driven at a second speed, which is higher than the first speed.

Abstract: In a control loop for automatically adjusting variable-gain amplification, a sinusoidal signal with a frequency f.sub.o that is critical for the control loop is superimposed over a positioning parameter W. Two synchronous rectifiers S1 and S2 filter out the oscillation components of a control parameter x and of a control difference x.sub.d that contain frequency f.sub.o, and the components are compared in a comparator VL. A control and regulating circuit C continues to vary the variable-gain amplification at controls RG until the amplitudes of the oscillation components being compared in the comparator are equal. The variable-gain amplification is correct at that point. The variable-gain amplification can even be adjusted in a compact-disk player while the player is in operation.