Abstract: An electric motor system has a motor having motor windings and a motor housing. The motor is a variable speed permanent magnet motor configured to drive a load which is part of a residential or commercial machine. A motor control subsystem includes a power module electrically connected to the motor windings. A common mode inductor is electrically interposed between the motor control subsystem and the motor windings so as to present a high impedance obstacle to common mode transients and to reduce an electromagnetic interference effect of an inherent capacitance of each of the motor windings. The common mode inductor is an air core inductor located substantially within the motor housing, and takes the form of additional turns added to the end of each of the motor windings.

Abstract: A control device of an electric power supply apparatus controls a voltage applied to an inverter to fall within a voltage range between a first voltage that is the voltage of one of a first electric power supply and a second electric power supply and a second voltage that is the sum of the voltage of the first electric power supply and the voltage of the second electric power supply, by alternately switching between a series state in which a current loop that connects the first electric power supply, the second electric power supply, and a reactor in series with the inverter is formed, and a parallel state in which the first electric power supply and the second electric power supply are connected in parallel with the inverter as an electric load.

Abstract: A method and a circuit for controlling an ac machine comprises controlling a full bridge network of commutation switches which are connected between a multiphase voltage source and the phase windings to switch the phase windings between a parallel connection and a series connection while providing commutation discharge paths for electrical current resulting from inductance in the phase windings. This provides extra torque for starting a vehicle from lower battery current.

Abstract: A power tool has an electric motor with field windings. Each field winding includes two coils. When the motor is first energized, the two coils of each field winding are connected in series, reducing in-rush current. Upon expiration of a soft start period, the two coils of each field winding are connected in parallel. In another aspect, the field windings that are connected in series with a separate start winding when the motor is first energized. Upon expiration of the soft start period, the start winding is bypassed. In another aspect, the field windings are connected in series with a start impedance when the motor is first energized and a time delay relay having a set of delay contacts coupled across the start impedance energized. Upon expiration of the soft start period, the time delay contacts close, bypassing the start impedance. In an aspect, the motor is a universal motor.

Abstract: Methods and apparatus for achieving a system, including: a polyphase machine having a plurality of sets of polyphase windings, each of the respective windings of a first of the sets of polyphase windings being inductively linked to one of each of the respective windings of the remaining sets of polyphase windings; a polyphase inverter operable to receive power from the windings of the first set and to produce a polyphase output; and a plurality of single-phase inverters, each operable to receive power from the windings of a respective one of the remaining sets and to produce a single-phase output, wherein each of the respective phases of the polyphase output may be coupled in series or parallel with one of the respective single-phase outputs to produce an aggregate polyphase output.

Abstract: A rotating electrical machine, such as an aircraft starter-generator, includes an exciter that has its stator windings divided into a number of sections. A plurality of switches are electrically coupled to the exciter stator winding sections and are configured and controlled so that the exciter stator winding sections may be selectively coupled in series or in parallel with one another, and selectively coupled to receive either DC or AC power.

Abstract: A method of adjusting speed and torque of a dynamoelectric machine is disclosed. The machine includes a main winding, and a divided winding each configured to generate a plurality of poles. The method includes the steps of energizing the main winding and controlling the amount of electromagnetic flux at each pole.

Abstract: A pair of DC motors, each having a shunt-connected field winding, are interconnected such that current supplied to the shunt field winding of one of the motors is proportional to the armature current in the other of the two motors when the speed of the other motor is between predetermined maximum and minimum speeds.

Abstract: A DC shunt or compound motor, in which an armature current detection device, provided to increase the current in the shunt field winding following an increase in armature load current, causes the motor to have characteristics similar to a series motor until a maximum setting value is reached, at which time the speed is held constant with increasing torque as is characteristic of a shunt-type motor. Below a minimum speed, the torque also increases as in a conventional shunt-type motor.

Abstract: A motor control circuit includes a series motor made up of a series field winding serially connected with an armature or a compound motor having both a series field winding and a shunt field winding. The series field winding is parallel connected to an auxiliary power supply and connected to the main motor driving power source via a switch which connects the series winding in series therewith during start-up or an overload condition and in parallel therewith during normal operation.

Abstract: A DC electrical motor of the form having one field winding connected in series with the armature winding in addition to a shunt field winding connected in parallel with the armature winding is provided with a diode or the like in the shunt field winding circuit. This blocks reversed current flow in the shunt field winding which can otherwise occur during start-up due to an inductive interaction with the series field winding and armature circuit. The diode or the like enables faster magnetization of the stator poles by preventing creation of negative shunt field ampere turns due to the magnetic couple with the series field-armature circuit during the motor start period. Faster starting of the motor results, and adverse effects such as heating, brush deterioration, and commutation problems are reduced.