Abstract: A power tool includes a motor, a first power source access circuit, a first drive circuit, a second power source access circuit and a second drive circuit. The motor includes a rotor, a stator, a plurality of first-type windings and a plurality of second-type windings. The rotor is configured to rotate about a central axis. The stator includes a ring-shaped yoke portion, and a plurality of teeth. The plurality of first-type windings are configured to be wound around part of the plurality of teeth and the plurality of second-type windings are configured to be wound around other part of the plurality of teeth. The first power source access circuit is configured to access a first power source with a first voltage. The first drive circuit includes a plurality of first-type electronic switches connected between the plurality of first-type windings and the first power source access circuit. The second power source access circuit is configured to access a second power source with a second voltage.

Abstract: A method for operating a mains-operated electric motor for a power tool includes connecting a first side of an electric motor to a first mains and connecting a second side of the electric motor to a second mains using first and second switches, respectively, in particular semiconductor switches, and monitoring the operational reliability of the switches using an electronic controller for operating safety.

Abstract: A drive device of the present invention includes a pair of drive switches, a first diode, a switching element, a current detection unit, a capacitor, a second diode, and a current control unit. The first diode, the switching element, and the current detection unit are arranged, in this order from one end of an armature in a motor, on a braking current path that is formed of the armature and a field winding in the motor when the pair of drive switches is in a brake position. The second diode is adapted to keep allowing a braking current to flow through the field winding when the switching element is in an off-state by directly connecting a partial path between the switching element and the current detection unit on the braking current path and the other end of the armature.

Abstract: In an electrically powered vehicle, a computer-controlled switching system activates relays to switch additional discrete batteries into a circuit in response to throttle level, where a processor is configured to decide what specific batteries should be present in the circuit at any given time, in response to both throttle level and a battery load balancing optimization scheme.

Abstract: An electric power tool is provided that includes a motor as a driving source, a first operation switch, a first semiconductor switch, and a second semiconductor switch. The first operation switch is operated by a user to be turned ON/OFF. The first semiconductor switch, provided on a current path from the power source to the motor, includes at least one semiconductor switching device. When the first operation switch is OFF, the first semiconductor switch is turned OFF to interrupt the current path. When the first operation switch is ON, the first semiconductor switch is turned ON to close the current path. The second semiconductor switch is provided on the current path in series with the first semiconductor switch and includes at least one semiconductor switching device. The second semiconductor switch closes/interrupts the current path by being turned ON/OFF in accordance with an input control signal.

Abstract: A method for controlling a rotary electrical machine and a control and power module for a rotary electrical machine. The rotary electrical machine includes a plurality of phase windings (9), a power circuit (12, 16) which comprises a plurality of arms each formed by a bridge of switches and which is capable of supplying an electrical network at an output voltage (Vres) equal to a nominal voltage when the bridge of switches is in a nominal mode of operation, an excitation winding (11) through which flows an excitation current (I exc) which generates a magnetic flux in a magnetic excitation circuit (10), and an electronic control circuit (7) which operates the power circuit and controls the excitation current. The method includes locking the bridge in at least one arm of the power circuit in a conductive state when the output voltage exceeds a voltage threshold higher than the nominal voltage. The nominal mode of operation of the bridge is returned to independently of the output voltage.

Abstract: A motor controller comprises a processor selectively outputting an on-signal to either one of an upper arm switching element and a lower arm switching element based upon a detected position by the position sensor, gate drivers inputting a driving voltage to the gates of the switching elements by shifting a level of the on-signal from the processor to the upper arm switching element and a bootstrap capacitor configured to be charged while the upper arm switching element is turned off and to behave as a voltage supply for the gate driver while the upper arm switching element is turned on. The processor is configured to reduce a set duty ratio when the set duty ratio is equal to or larger than a predetermined value (e.g. 80 percents) and a rotational position of the motor does not change for a first predetermined time. This motor controller can prevent the switching element from a burnout even if the motor is locked.

Abstract: A drive device of the present invention includes a pair of drive switches, a first diode, a switching element, a current detection unit, a capacitor, a second diode, and a current control unit. The first diode, the switching element, and the current detection unit are arranged, in this order from one end of an armature in a motor, on a braking current path that is formed of the armature and a field winding in the motor when the pair of drive switches is in a brake position. The second diode is adapted to keep allowing a braking current to flow through the field winding when the switching element is in an off-state by directly connecting a partial path between the switching element and the current detection unit on the braking current path and the other end of the armature.

Abstract: The present invention includes a control device capable of applying a high voltage to a motor of a fuel pump for an appropriate period of time during a low voltage operation of the motor.

Abstract: An electric power tool is provided that includes a motor as a driving source, a first operation switch, a first semiconductor switch, and a second semiconductor switch. The first operation switch is operated by a user to be turned ON/OFF. The first semiconductor switch, provided on a current path from the power source to the motor, includes at least one semiconductor switching device. When the first operation switch is OFF, the first semiconductor switch is turned OFF to interrupt the current path. When the first operation switch is ON, the first semiconductor switch is turned ON to close the current path. The second semiconductor switch is provided on the current path in series with the first semiconductor switch and includes at least one semiconductor switching device. The second semiconductor switch closes/interrupts the current path by being turned ON/OFF in accordance with an input control signal.

Abstract: A device is provided for detecting inadequate electric braking and commutation to a safety brake is intended for a vehicle with electric traction, in particular a rail vehicle, which is provided with a traction chain, the system including a first electric, non-safety brake which is integrated in the traction chain and a second safety brake. The device includes a member for commutation from the first brake to the second brake, a device for monitoring the braking performance of the first brake using data for measurement of the intensity of a current, a decision device for commutating from the first brake to the second brake when a predetermined threshold value is exceeded and a device for transmitting a commutation command to the at least one commutation member.

Abstract: This device is an electric safety brake which is intended for an electric traction vehicle, in particular a rail vehicle comprising: a rotating electromechanical machine (10) having permanent magnets having at least one coil with electric terminals (13, 14, 15), a resistive braking torque production device (22), an electromechanical commutator (20) which is capable of reliably connecting the electric terminals (13, 14, 15) of the machine (10) to the braking torque production device (22).

Abstract: A DC motor including a stator which includes a shell, a main magnetic pole and an exciting coil; a rotator disposed inside the stator; a brush holder disposed at an end of the shell; first and second carbon brushes disposed on the brush holder and contacted with the rotator respectively; a current direction controller disposed on the brush holder and connected with the first and second carbon brushes and first and second ends of the exciting coil respectively so as to control a direction of a current supplied to the exciting coil; and a cover disposed at the end of the shell so as to enclose the brush holder. The motor according to the present invention is compact in structure, small in volume, and occupies a small mounting space, and the work load of sealing and insulating is reduced, thus reducing the cost and improving the manufacture efficiency.

Abstract: A method and apparatus of interfacing a Hall sensor to a commutation circuit comprises receiving output signals from the Hall sensor; detecting when the Hall sensor output signals are within a predetermined range; generating commutation output signals when the Hall sensor output signals are in a predetermined state for a predetermined period of time; and locking out a change in the commutation output signals for a second predetermined period of time.

Abstract: A solid state series motor control includes first and second FORWARD DRIVE elements, first and second REVERSE DRIVE elements, first and second diodes, a current sensor, and a capacitance. The series motor control is configured to be interconnected with controlling logic or a processor, the field and armature of a series wound motor, and an external DC power source. The FORWARD DRIVE elements and REVERSE DRIVE elements can be IGBTs or similar semiconductors. The current sensor is configured to measure current passing through the motor armature. The capacitance is a combination of a line filter and source impedance reduction for IGBT switching. The solid state series motor control can control the speed and direction of a series wound motor using solid state components while maintaining the series connection of the armature and the field winding.

Abstract: A position sensor generates a signal representative of the angular position and, if desired, angular velocity of a rotating object using only a single circular track and plural brushes that ride on the track when the object rotates. The single circular track can have plural segments, and the sensor can generate more than one signal cycle per revolution.

Abstract: A motor drive apparatus includes a comparison circuit comparing voltages of 3-phase coil terminals and the voltage of a neutral point terminal of a 3-phase brushless motor to determine which voltage is higher/lower, a zero ampere current detection circuit detecting, based on the comparison result by the comparison circuit, that the coil current of a position detection phase becomes 0 A, a position detection circuit detecting a zero cross point of the voltage of the position detection phase based on the comparison result by the comparison circuit after the coil current becomes 0 A. Therefore, the zero cross point can be accurately detected without introducing a mask period.

Abstract: An apparatus for determining angular positions of DC motor includes a capacitor connected in parallel with the DC motor. The current flowing through the capacitor, at any given time, is an AC ripple current responsive to a commutation event of the DC motor. The capacitor partially sources the motor current ripples during commutation and recharges itself during the off-commutation period. Since the number of commutation events per mechanical revolution is pre-determined once the DC motor is designed, the frequency of the AC ripple currents through the capacitor corresponds to the frequency of commutation, and thus a motor position of the DC motor.

Abstract: A dual current-limiting circuit for a dc brushless motor includes an over-current detective circuit, an operation detective circuit, and a current-limiting circuit. The over-current detective circuit produces a voltage signal used to determine whether an over-current has been input to the motor. The operation detective circuit also produces a voltage signal used to determine whether the motor is being operated in a normal manner. The current-limiting circuit decides to turn on a first switch of a first current-limiting circuit and to subsequently turn on a second switch of a second current-limiting circuit depending upon the two voltage signals. The current-limiting circuit is capable of suppressing current passing through a coil at a low voltage level, which is inadequate to damage a driver circuit and still adequate to restart the motor if an abnormal input current is eliminated.

Abstract: A vehicle control apparatus performs regenerative braking by regeneratively operating first and second motor-generators to apply first and second braking torques in response to a deceleration request. The vehicle control apparatus is improves the efficiency in regeneratively generating electric power without greatly disturbing the balance between the. The control apparatus calculates an ideal front-rear wheel distribution ratio for front wheel braking torque and the rear wheel braking torque, and also calculates a distribution allowance for the ideal front-rear wheel distribution ratio. The control apparatus then corrects the ideal front-rear wheel distribution ratio within the distribution allowance such that the electric power generation efficiencies of the first motor-generator connected to the rear wheels and the second motor-generator connected to the front wheels are increased.

Abstract: A drive system for a domestic appliance provides inner and outer coaxial drive outlets operative at different speeds and comprises an active limb, which incorporates an electric drive motor and a shaft driven by said motor and coupled to the inner drive outlet to drive it at a selected speed. The system also includes a passive limb which incorporates a rotary component; the two limbs being mounted in fixed relationship to one another. A first speed reduction mechanism couples the shaft to the rotary component of the passive limb and a second speed reduction mechanism couples the said rotary component to the outer drive outlet. Conveniently, the rotary component comprises a further shaft, disposed substantially parallel to the driven shaft of said motor, and both limbs of the system are rigidly mounted to, and supported by, a common framework of support members. Both speed reduction mechanisms are typically belt driven, and may provide identical reductions.

Abstract: An H-type motor bridge coil driver circuit is implemented with an electronic switch in each leg segment of an H-shaped circuit, this bridge circuit having its side legs each connected between a power supply and ground, with the inductive load of a motor coil being connectable as the cross leg of the H-shaped circuit. An alternate current path, voltage level stabilizing element may be connected across each leg segment electronic switch. A coil excess energy storage element may be connected to the coil nodes of the circuit, through alternate current path elements and utilized to temporarily store the discharging of the excess coil energy normally available because of the lagging nature of the motor coil current. This temporary storage element then may discharge this energy back to the power supply through a passive circuit element, and reverse polarity protection is included for the power supply.

Abstract: In the three-terminal motor operator of the present invention, current flowing through half coil causes the rotor to rotate in a first direction, and current flowing through half coil causes the rotor to rotate in a second direction. Rotation of the rotor in the first direction causes the mechanical linkage to move the circuit breaker operating handle towards its “off” or “reset” positions. Rotation of the rotor in the second direction causes the mechanical linkage to move the circuit breaker operating handle towards its “on” position. Pressing the “off” button causes electrical current to flow through the half coil until the circuit is broken by the limit switch. Pressing the “on” button causes electrical current to flow through the half coil until the circuit is broken by the limit switch.

Abstract: A series motor with commutator is disclosed which is especially suited as universal motor for a braked power tool. The series motor comprises a switch for switching between a motor mode and a braking mode, wherein, in motor mode, at least one field winding is connected in series with an armature winding in a motor circuit, which is connected to an a.c. power source, and wherein, in braking mode, the at least one field winding and the armature winding form together a closed braking circuit disconnected from the power source. The secondary winding of a mains-operated transformer is connected within the braking circuit. This arrangement guarantees improved safety of the braking action.

Abstract: A series wound commutator motor is disclosed which is particularly suited for an inverse-speed electric tool. A switch is provided for switching between a motor operation mode and a braking operation mode, wherein in motor operation at least one field coil is connected in series with an armature winding in a motor circuit fed with a voltage supply and wherein in braking operation the at least one field coil with the armature winding forms a closed braking circuit separated from the voltage supply. A mains-supplied transformer is provided whose secondary winding is connected in the braking circuit parallel to the at least one field coil. A transistor circuit is provided for controlling the current flowing in the braking circuit through the armature winding and the at least one field coil.

Abstract: A fixture to evaluate stator production quality is placed about a stator core so as to introduce a test winding about the stator without need for hand winding. The fixture includes an inner annulus and an outer annulus each with axial conductors thereon, and top and bottom plates each with conductors thereon. The core is fitted between the inner and outer annuli, and between the top and bottom plates. The inner axial conductors and outer axial conductors are connected to one another at their lower ends through the bottom plate conductors and at their upper ends through the top plate conductors. Once testing is complete, the fixture is easily removed.

Abstract: In a method of starting a two-pulse electronically commutated dc motor, which is designed for operation in a preferred direction, for purposes of startup in a desired direction, the following steps are carried out: after start-up, the rotor of the motor is driven, according to a start routine (S118), by supplying current alternately in a first and a second direction, into forced oscillation about a rest position; during the start routine, monitoring (as to whether the rotor has started up) is performed; whenever it is determined that the rotor has started up, the start routine is exited. Further, a method is provided, by means of which the rotational position of the rotor, at which the current of a winding phase is switched on, is optimized as a function of rotation speed and rotation direction.

Abstract: An anti-regeneration circuit for preventing a regenerated current produced by an overhauling DC motor from setting a series brake. The anti-regeneration circuit includes a current blocking device 90 which blocks the flow of regenerated current in the crane control circuit 10 and a surge suppresser 94 for protecting the current blocking device 90 from a high inverse peak voltage produced by de-excitation of a crane control circuit 10 upon the sudden loss of power.

Abstract: A braking circuit for a universal motor is proposed, in which, during braking, the at least one field winding is connected in series with the armature by means of a semi-conductor switch, preferably a field effect transistor or a thyristor. Since the semiconductor switch can also be switched intermittently and with a time delay, not only is it possible to regulate the braking current simply, but there is also a reduced formation of sparks at the collector. The reduction in the contact erosion lengthens the service life and increases the reliability of the motor.

Abstract: In a series-wound motor with electric brake, which comprises an armature provided with an armature winding and at least two exciter coils mounted on pole shoes as well as switchgear which, in the operative phase of the motor, serially connect the exciter coils with the armature winding and connect the serial connection to terminal clamps for the operating voltage and which, in the braking phase, interrupt the connection to the terminal clamps and short-circuit the armature winding by the parallel connection of a winding, an independent optimization of the braking behavior is made possible in that at least one of the exciter coils is subdivided into two part windings and in that, when braking, one of the part windings has its polarity changed and is short-circuited with the armature winding.

Abstract: Current control apparatus of DC motor includes current amplifying means for detecting the current amount at the rear end of the motor and amplifying the current value; on-off control means for comparing the input current with the current supplied from the current amplifying means and outputting an on-off control signal according to the current amount; and microcomputer for controlling the duty value of the pulse wave of a predetermined frequency occurring in accordance with the on-off control signal from the on-off control means and controlling the on-off time of the chopper transistor.

Abstract: A travel drive for a trolley traveling gear of hoists has a drive train which has the properties of a freewheel as regards the direction of travel. Consequently load oscillation can be rapidly damped out because the speed of the traveling gear is not forcibly held constant during the semioscillation of the load in which it moves ahead of the traveling gear. On the contrary, the swinging load is able to drag the traveling gear behind it, accelerating it in the process, and in this way to convert oscillation energy into driving energy.

Abstract: A series-wound motor, wherein, for braking purposes, the polarity of the armature of the motor is reversed for the opposite direction of rotation. The current supply for the motor is maintained until the armature comes substantially to a standstill and subsequently, the current supply to the motor is interrupted. The braking time is controlled in dependence upon operating parameters. For example, the braking time can be controlled by a predetermined time constant for the interruption of the current supply. To prevent running in the opposite direction, a reversal preventing device can be provided.

Abstract: A control circuit for a series type dc motor. The control circuit uses a switching cell to control motor speed. The switching cell and motor receive power from a filtered dc supply. A tachometer generator produces a voltage proportional to motor speed. The speed voltage is compared to a speed reference signal voltage and the difference is proportionally integrated to develop a speed error signal voltage. The speed reference signal voltage is developed at a summing node where a current generated by the control's microcontroller is summed with a current proportional to the input ripple voltage of the control's dc supply. The microcontroller also receives a voltage proportional to the control's dc input as a reference. The speed error signal voltage is compared with the output voltage of a current sensor that is in series with the motor feeder arrangement and the comparator's output is used to reset a bistable flip flop.

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: Motor control system for unidirectional series DC electric motor having improved dynamic braking performance for smoothly, rapidly and predictably stopping the motor armature so that any operated devices are similarly stopped at a predetermined location. The control system uses a bridge conformed like a full-wave rectifier together with a pair of switches having open and closed positions to control the direction of current through the armature. The current through the motor field winding is always in the same direction. The control switches are protected against arcing when breaking an inductive load.

Abstract: A circuit arrangement for regulating the rpm of an electric motor having series connected field and armature windings 1, 4 comprises a controllable rectifier 5 which is connected in series with the motor and is controlled by a phase control unit 30 as a function of a control signal obtained at armature winding 1 and conducted via an operational amplifier 12. To achieve a very constant rpm and a high regulating speed with simple means, each terminal of armature winding 1 is connected to one input 10, 11 of a differential amplifier 12 whose output 15 is connected to one input 19 of a comparator. At its second input, the comparator is given a desired value signal which is changed in dependence upon the current flowing through armature 1.

Abstract: A method of controlling and a controller for controlling at least one series motor is provided. Rectifier means is connected in series with the motor so that current through a field winding of the motor is always in the same direction irrespective of the polarity of the input voltage while the current direction through an armature of the motor reverses in accordance with the polarity of the input voltage. An energizing current is applied to the field winding by a bias power supply to ensure that the field winding always produces some flux during operation of the motor.

Abstract: A variable frequency drive for a motor-generator/alternator set which is used to supply electrical power to computer or data processing equipment. Power failures in commercially supplied power results in aberrations and erroneous computations in computers and data processing equipment. An induction motor is used to drive a generator/alternator. The induction motor is driven below the synchronous speed of the generator/alternator and a variable speed drive increases the velocity supplied to the generator/alternator, preferably to a point above its synchronous speed. Therefore, when there is a commercial power failure, the generator/alternator remains within a desired frequency range for a longer period of time than a comparable generator/alternator driven at synchronous speed.

Abstract: An electronic switch for variably controlling the speed of an electric motor, comprising a stationary member, a trigger member, clip means for securing said trigger member slidably relative to said stationary member, a pair of electric cords extending from the inside of said trigger member for connecting said electronic switch in circuit with an electric motor and power source, switching means and a solid-state semiconductor control device supported within said trigger member; characterized in that, said switching means comprising two sets of contacts, with one set including three electrically conductive contacts, another set including one electrically conductive contact and a resistor for providing various resistance values, disposed on said trigger member in spaced relation to each other, and two electrically conductive bridging contacts mounted on said stationary member in isolated relation to each other for contacting with the respective set of contacts; while said trigger member being manually actuated w

Abstract: A d.c. control circuit includes a slew-rate limiting circuit interposed between a current sensing device which detects current in a load and a control circuit, for switching on and off a thyristor controlling current through the load. The circuit limits the slew rate to a level in excess of the maximum normal current slew rate through the load.