Abstract: In a power converter, a control circuit has a speed adjustment resistor that limits a control current to adjust a switching speed of each of first and second switching elements. The speed adjustment resistor has a resistance that varies depending on a voltage at the control electrode of each of the first and second switching elements. A feedback route connects between the control electrode of the first switching element and the control electrode of the second switching element. The feedback route has a resistance that is set to be lower than a value of the resistance of the speed adjustment resistor during a predetermined Miller period of each of the first and second switching elements.

Abstract: Certain embodiments of a system for reducing backlash include a member geared for rotation in first and second directions. In various implementations, a first motor causes rotation in the first direction with an output biased to preclude space between mating gear components in the first direction, and a second motor, which is mechanically independent of the first motor, causes rotation in the second direction with an output biased to preclude space between mating gear components in the second direction.

Abstract: Motor drives and switch driver power systems are presented in which high frequency AC current (IHF) is provided through one or more cables (202) magnetically coupled with local driver current transformers (240), and the transformer secondary currents are converted to provide DC power to switch drivers of an active power converter stage (110a, 110b) in the motor drive.

Abstract: Power conversion systems with active front end converters for example motor drives and power generation systems for distributed energy sources are presented with adaptive harmonic minimization for grid-tie converters for minimized or reduced total harmonic distortion in the line current spectrum including the source harmonic current and the grid-tie converter injected current spectrum referred to the line side.

Abstract: A circuit arrangement for controlling an electrical load is provided with a bridge circuit which comprises four electronic switches with the load arranged in a transverse leg of the bridge circuit. A control circuit has respective control terminals for the four electronic switches. The control terminal for the first electronic switch is connected to the control terminal for the fourth electronic switch by means of a series connection consisting of a first capacitor and a first resistance, and the control terminal for the third electronic switch is connected to the control terminal for the second electronic switch by means of a series connection consisting of a second capacitor and a second resistance.

Abstract: The invention relates to a circuit arrangement for controlling an electrical consumer (M), said arrangement being provided with a bridge circuit which comprises four electronic switches (V1, V2, V3, V4) and the consumer (M) which is arranged in the transversal leg of the bridge circuit, and a control circuit (uC) comprising control terminals for the four electronic switches. The control terminal for the first electronic switch (V1) is connected to the control terminal for the fourth electronic switch (V4) by means of a series connection consisting of a first capacitor (C1) and a first resistance (R1), and the control terminal for the third electronic switch (V3) is connected to the control terminal for the second electronic switch (V2) by means of a series connection consisting of a second capacitor (C2) and a second resistance (R2).

Abstract: A motor drive and a choke therefor are disclosed, wherein the choke comprises a magnetic core with an inner leg and two outer legs, and four coils, which may be connected in DC current paths in the motor drive. First and second differential coils are wound around first and second outer legs, respectively; and first and second common-mode coils are wound around the inner leg of the choke. The first and second differential coils smooth the DC current on a DC bus in the motor drive, and the first and second common-mode coils suppress common-mode voltages in the motor drive. Also disclosed is a method for suppressing common-mode voltages in a motor drive.

Abstract: The present invention provides an apparatus for controlling power factor compensation and method thereof, in which a turn-on timing point of a power factor compensation switch is delayed by a prescribed time from a zero crossing timing point to enhance a power factor. The present invention includes periodically detecting a zero crossing time point of an inputted voltage, turning on the power factor compensation switch if a turn-on time point of the power factor compensation switch set to a time point delayed by a prescribed time from the detected zero crossing time of the inputted voltage is reached, and turning off the power factor compensation switch if a prescribed time passes after turning on the power factor compensation switch.

Abstract: A motor drive and a choke therefor are disclosed, wherein the choke comprises a magnetic core with an inner leg and two outer legs, and four coils, which may be connected in DC current paths in the motor drive. First and second differential coils are wound around first and second outer legs, respectively; and first and second common-mode coils are wound around the inner leg of the choke. The first and second differential coils smooth the DC current on a DC bus in the motor drive, and the first and second common-mode coils suppress common-mode voltages in the motor drive. Also disclosed is a method for suppressing common-mode voltages in a motor drive.

Abstract: A motor drive and a choke therefor are disclosed, wherein the choke comprises a magnetic core with an inner leg and two outer legs, and four coils, which may be connected in DC current paths in the motor drive. First and second differential coils are wound around first and second outer legs, respectively; and first and second common-mode coils are wound around the inner leg of the choke. The first and second differential coils smooth the DC current on a DC bus in the motor drive, and the first and second common-mode coils suppress common-mode voltages in the motor drive. Also disclosed is a method for suppressing common-mode voltages in a motor drive.

Abstract: A motor drive and a choke therefor are disclosed, wherein the choke comprises a magnetic core with an inner leg and two outer legs, and four coils, which may be connected in DC current paths in the motor drive. First and second differential coils are wound around first and second outer legs, respectively; and first and second common-mode coils are wound around the inner leg of the choke. The first and second differential coils smooth the DC current on a DC bus in the motor drive, and the first and second common-mode coils suppress common-mode voltages in the motor drive. Also disclosed is a method for suppressing common-mode voltages in a motor drive.

Abstract: A half wave and full wave energization system for permanent magnet D.C. motors employing a hand trigger operated switch which commutates terminals of a full wave rectifier bridge when connected to a source of A.C. supply to provide selectively half wave and full wave energization of such motors when the trigger is depressed from an extended "off" position.

Abstract: Negative sequence compensation apparatus for reducing, and thereafter minimizing the increase of, negative sequence currents flowing in a three phase motor includes variable impedance elements, and means for adjusting the impedance thereof, disposed in the motor supply lines. Alternate embodiments disclose saturable reactors as the variable impedance elements electrically connected with the supply terminals by way of alternate transformer connections.