Abstract: The invention provides a separately excited direct current motor drive apparatus and electric equipment.

Abstract: A motor starter includes a plurality of semiconductor switches configured to couple respective phases of an AC power source to respective phases of a motor and a control circuit configured to configured to selectively operate the semiconductor switches to gradually increase a voltage applied to the motor, to determine root mean square (RMS) current values of a current of the motor as the voltage increases, and to cause the semiconductor switches to apply a full voltage or a more steeply ramping voltage to the motor responsive to the RMS current values meeting a criterion.

Abstract: A heater having a helical electrical resistance heating wire connected to and coiled around a current return wire. The heater is employed in thermal conduction heater wells used for removing contaminants from soil, groundwater or rock.

Abstract: An electrodynamic braking device for a universal motor is proposed, wherein during a braking operation a field winding is supplied from a network, and an armature is directly short-circuited, and a braking operation is carried out using a program of a controller of a control electronics system, whereby good braking is achieved with relatively low brush wear. Such an electrodynamic braking device is advantageously applied in a power tool equipped with a dangerous tool.

Abstract: A method for braking the thermal engine of an automobile using a multiple-phase rotary electric machine (1) connected to the thermal engine and including a stator and a rotor (4) having at least one excitation winding (41). A shortcut of at least one phase of the multiple-phase rotary machine is included during the stop phase of the thermal engine. The multiple-phase rotary electric machine is capable of braking the thermal engine of an automobile during the stop phase thereof due to the fact that a shortcut is induced, during the stop phase of the thermal engine, of at least one of the phases thereof.

Abstract: The invention relates to an electrodynamic braking device and to a method for braking a universal motor having a field winding and an armature. The universal motor can be switched from a motor mode to a braking mode. In the motor mode, the armature and the field winding are supplied with an alternating current of a power grid. In the braking mode, the armature is short-circuited and the field winding continues to be supplied with an alternating current from the power grid. In a first phase of the braking mode, the field winding can be supplied with an alternating current having the frequency of the power grid. In a further phase of the braking mode, the field winding is supplied by the power grid with an alternating current having a frequency that is reduced with respect to the frequency of the power grid.

Abstract: A braking circuit is adapted to supply generatively produced energy of the motor as load resistance to a bipolar transistor. The braking circuit has a voltage regulator, which controls a voltage, applied to the base terminal of the bipolar transistor to achieve an associated controlled voltage based on a reference voltage. A first power supply connector of the electrical motor, in the generator mode of operation of the electrical motor, is coupled to a collector terminal of the bipolar transistor and to the voltage input of a voltage regulator. A second power supply connector of the electrical motor is coupled to an emitter terminal of the bipolar transistor and is coupled to a reference input of the voltage regulator via a resistive branch including at least one electrical resistor.

Abstract: An electrodynamic braking device for a universal motor is proposed, wherein during a braking operation a field winding is supplied from a network, and an armature is directly short-circuited, and a braking operation is carried out using a program of a controller of a control electronics system, whereby good braking is achieved with relatively low brush wear. Such an electrodynamic braking device is advantageously applied in a power tool equipped with a dangerous tool.

Abstract: A system for braking a motor. The system includes at least one resistor and a contactor connected to the at least one resistor and a motor. The system further includes a variable frequency drive electrically connected to the motor, wherein the variable frequency drive comprises a controller operably connected to the contactor, wherein at least a portion of the contactor closes connecting the at least one resistor to the motor in response to a command from the controller. The variable frequency drive is configured such that motor flux levels may be maintained at a relatively high level as motor torque current is reduced, resulting in a consistently high motor flux level as the motor speed decreases.

Abstract: The invention relates to a circuit arrangement for recirculating the energy produced during the braking of electric motors into a supply system. The object of the invention is to implement the feeding of the energy that can be obtained when braking electric motors to the supply system without the use of an isolating transformer. Said object is solved by a forward branch (3), comprising a rectifier (32) connected to the supply system (1). The rectifier is guided via a first intermediate circuit (33) to a first inverter (34) that is connected to the motor (2), and a backward branch (4), comprising a second intermediate circuit (42) connected to the output of the first intermediate circuit (33), wherein a second inverter (41) is connected to the second intermediate circuit, and the second inverter in turn is connected to the supply system (1) via a mains circuit (5).

Abstract: The invention relates to an electrodynamic braking device and to a method for braking a universal motor having a field winding and an armature. The universal motor can be switched from a motor mode to a braking mode. In the motor mode, the armature and the field winding are supplied with an alternating current of a power grid. In the braking mode, the armature is short-circuited and the field winding continues to be supplied with an alternating current from the power grid. In a first phase of the braking mode, the field winding can be supplied with an alternating current having the frequency of the power grid. In a further phase of the braking mode, the field winding is supplied by the power grid with an alternating current having a frequency that is reduced with respect to the frequency of the power grid.

Abstract: The invention relates to a traction drive for the driving and generative braking of a rail vehicle or a combination of rail vehicles, at least one permanent-field synchronous motor and a traction current converter being associated with at least one axle of the rail vehicle or combination of rail vehicles. The traction current converter includes at least one pulse current converter on the engine side, and the clamps of the permanent-field synchronous motor are connected to a change-over switch such that the permanent-field synchronous motor can be connected to a load circuit forming a load, to drive the pulse current converter or for generative braking. According to the invention, the load circuit connected to the permanent-field synchronous motor for generative braking is designed and/or controlled in such a way that the characteristic values of the load circuit can be modified according to the loading of the rail vehicle or combination of rail vehicles.

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: A method for braking the thermal engine of an automobile using a multiple-phase rotary electric machine (1) connected to the thermal engine and including a stator and a rotor (4) having at least one excitation winding (41). A shortcut of at least one phase of the multiple-phase rotary machine is included during the stop phase of the thermal engine. The multiple-phase rotary electric machine is capable of braking the thermal engine of an automobile during the stop phase thereof due to the fact that a shortcut is induced, during the stop phase of the thermal engine, of at least one of the phases thereof.

Abstract: A fan system includes a stator magnetic pole, a driving unit and a real-time stopping unit. The driving unit is coupled with the stator magnetic pole and controls a polarity change of the stator magnetic pole in accordance with a driving signal. The real-time stopping unit is electrically connected with the driving unit. When the fan system is powered off, the driving unit enables two ends of the stator magnetic pole to have the same voltage level in accordance with a control signal generated by the real-time stopping unit so that the fan system stops operating immediately.

Abstract: Disclosed is an electric drive for a vehicle, which is used as a main drive or a hybrid drive. The electric motor of said drive is embodied as a special type of reluctance motor or series wound motor. The rotor of the reluctance motor and the inverse speed motor is provided with an excitation winding to which a transistor is assigned that allows the motor to be braked in a sensitive manner so as to control the field current. The braking current is fed to the source of current by switching operation of the motor during generator operation.

Abstract: A system for braking a motor. The system includes at least one resistor and a contactor connected to the at least one resistor and a motor. The system further includes a variable frequency drive electrically connected to the motor, wherein the variable frequency drive comprises a controller operably connected to the contactor, wherein at least a portion of the contactor closes connecting the at least one resistor to the motor in response to a command from the controller. The variable frequency drive is configured such that motor flux levels may be maintained at a relatively high level as motor torque current is reduced, resulting in a consistently high motor flux level as the motor speed decreases.

Abstract: The present invention is directed to the termination of the occurrence of wheel slip/skid and prediction and prevention of the onset of wheel slip/skid in a locomotive. In one configuration, a lookup table of adhesion factors is used to predict the occurrence of wheel slip/skid.

Abstract: Provided is a drive regenerative control system of a drivee with a motor superior in torque and weight balance and suitable for miniaturization as the drive source. In a drive regenerative control system having a drive source with an electric motor, a drivee, a control circuit having a drive control circuit of the motor and a regenerative control circuit, and a detection unit for detecting the driving status of the drivee, the drive control circuit and regenerative control circuit have a control unit for controlling, linearly or in multiple stages, the duty ratio of the drive or regenerative signal to be supplied to the motor based on the phase difference of the phase of the detection signal from the detection unit and the command value signal to the motor.

Abstract: Provided is a drive regenerative control system of a drivee with a motor superior in torque and weight balance and suitable for miniaturization as the drive source. In a drive regenerative control system having a drive source with an electric motor, a drivee, a control circuit having a drive control circuit of the motor and a regenerative control circuit, and a detection unit for detecting the driving status of the drivee, the drive control circuit and regenerative control circuit have a control unit for controlling, linearly or in multiple stages, the duty ratio of the drive or regenerative signal to be supplied to the motor based on the phase difference of the phase of the detection signal from the detection unit and the command value signal to the motor.

Abstract: A motor power supply including a DC supply part having a pair of supply terminals; an inverter having a pair of connection terminals respectively connected to the supply terminals thereof to receive DC power therefrom and to supply AC power to a motor, a breaking resistor and a control switching element disposed in parallel in an additional line connecting the pair of connection terminals to each other, a control switching element disposed with the breaking resistor in the additional line, a breaking switch disposed to one of the connection terminals and switched to either a normal position or a breaking position connecting the one connection terminal to a corresponding supply part or to the additional line, a speed detector detecting a motor speed and a control part controlling the breaking switch to switch to the breaking position and controlling the control switching element so that an on-off interval of the control switching element is controllable depending on the detected speed.

Abstract: A braking device for an electric motor of a power tool has a short circuit switch for short circuiting an armature winding of the electric motor during a braking process, the short circuit switch for controlling its switch condition having a control input, a control unit connected with the control input of the short circuit switch for performing a phase control of the short circuit switching during the braking process in order to avoid brush fire; also an electrical device with such a braking device and a braking method are proposed as well.

Abstract: The present invention is directed to the termination of the occurrence of wheel slip/skid and prediction and prevention of the onset of wheel slip/skid in a locomotive. In one configuration, a lookup table of adhesion factors is used to predict the occurrence of wheel slip/skid.

Abstract: In an electronic system, motor braking is accomplished by applying direct current (DC) voltage, developed across a capacitive element during a run mode operation, across terminals of an alternating current (AC) or an induction motor. While the motor is ON, i.e. during the run mode operation, a diode rectifies an AC input voltage applied across a capacitor for charging thereof. Resistive elements in series with the capacitor control a charging rate thereof. When a relay or switch flips over to a STOP or OFF mode, i.e. a braking mode operation, all of the stored DC voltage, which was charged across the capacitor during the run mode operation, is dropped across a coil of the motor. This DC voltage creates an electric force applied to stop quickly and efficiently the motor shaft rotation. In preferred embodiments of the invention, it was found that the higher the capacitance of the electrolytic capacitor, the faster and more efficient the stopping action will be for the motor.

Abstract: An electrical machine comprises a rotor without windings, a stator having an armature winding 24, 25 and a field winding 10 for generating a magnetomotive force in a direction extending transversely of the magnetomotive force generated by the armature winding. An electronic circuit 40 is provided for controlling the current in the armature winding 24, 25 such that periods in which a magnetomotive force in one direction is associated with a first current pulse alternate with periods in which a magnetomotive force in the opposite direction is associated with a second current pulse. A position sensor is provided for monitoring the rotational position of the rotor and for supplying output signals at a rate dependent on the speed of rotation of the rotor. Furthermore a control system supplies control signals to the circuit 40 to control the current in the armature winding 24, 25 in response to the output signals.

Abstract: A method and apparatus for controlling a barrier movement operator comprising a controller that dynamically controls barrier operator braking to electronically slow, stop or reverse the motor in the barrier operator controller. The apparatus includes a source of electrical power for providing the necessary power to operate the apparatus, a converter for supplying power to a DC motor, and a controller for enabling dynamic braking of the movable barrier operator using electronic braking of the electric motor. The dynamic braking of the motor gradually slows movement of the barrier operator, thereby reducing forces acting on the motor and on the barrier.

Abstract: A method and apparatus for braking a motor has a braking power switching device coupled across windings of the motor. To brake the motor, the braking power switching device is cycled on and off.

Abstract: The present invention regards an electronic device for controlling the electromagnetic self-braking current in reversible rotating electric commutator machines, fitted with an inductor winding and an armature winding, in which there are reversing means to control the functioning of the electric machine as a generator by mutual inversion of the polarity of said inductor winding and said armature winding. The device includes a switchable current control circuit and an excitation circuit distinct from each other. The control circuit includes an electric load, a power device for connecting and disconnecting said electric load in series in the input circuit of said inductor winding to dissipate the power produced by said electric machine when it functions as a generator, and a variable duration pulse generator for controlling the switching of said power device.

Abstract: An electronic brake system for D.C. motors that utilize an electronic switching device in parallel with the motor upon the removal of a D.C. source. A bias circuit is connected to the switching device to keep it in the OFF condition while the D.C. source is applied to the motor. Upon disconnecting the D.C. source, through another switch, the electronic switching device can also be independently biased to permit the motor to coast. A properly biased FET can be used as the electronic switching device with a voltage limiting device connected from the gate to the source, such as a zener diode.

Abstract: A mains braking device for a line-powered power tool includes a circuit arrangement with a two-pole switch which switches between the motor mode and the braking mode. The inventive braking device further includes an electronic power circuit breaker or triac which is connected in series to the commutator motor of the power tool and with control electronics allocated to the triac. For the safe recognition and initiation of the mains braking mode, the control electronics is provided with devices for differentiating between the motor mode and the mains braking mode. The mains braking device is especially useful for power tools such as right angle grinders, hand-held buzz saws and the like which are provided with dangerous tools.

Abstract: Disclosed a vehicle speed control system using wireless communications, the system including a driving state detecting unit for detecting a driving state and outputting corresponding signals; a transmitter/receiver for outputting low-strength signals; an electronic control unit for receiving the signals of the transmitter/receiver and establishing an ISA mode if necessary, determining if a present driving state corresponds to a first driving state, determining if the driver has performed deceleration operations and performing control into the first driving state if needed; an engine control unit for outputting signals for control of the throttle valve opening; a throttle valve electronic control unit for outputting electrical signals to a throttle valve to control the same; and a display for displaying a present mode and a vehicle state.

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: The invention is a dynamic brake for a power door which is moved by an electric motor having at least two terminals. The motor is energized by a pulse width modulated door drive amplifier connected to a first power line and a second power line. The door drive amplifier has a first group of switches connecting the motor terminals to the first power line and it has a second group of switches connecting the motor terminals to the second power line. The dynamic brake has a brake control signal generator connected to receive an input signal indicative of a need to apply the dynamic brake and it has at least one output signal line connected to a control input of at least two of the switches in the first group of switches.

Abstract: An electric motor (10,110,210) comprises a TRIAC (16, 116, 216) for controlling the application power to the motor and a switch (18,118,215a) for controlled cut-off of the power supply. Upon operation of a switch (15b, 115B, 215B) for short-circuiting of motor from a power supply (13, 14; 113,114; 213,214) armature the power is supported to the field windings (12,112,212) with at least one predetermined braking voltage. Upon exhaustion of a braking period, the switch mechanism operates to cut off power completely from the motor.

Abstract: An electric motor (10, 110, 210) is coupled to a TRIAC (16, 116, 216) for controlling the application of power to the motor from a power supply (13, 14; 113, 114; 213, 214) and a switch (18, 118, 215a) for controlled cut-off of the power supply. Upon operation of a switch (15b, 115b, 215b) for short-circuiting an armature (11, 111, 211) of the motor, power is supplied to field windings (12, 112, 212,) of the motor with at least one predetermined braking voltage. A braking period can be established following short-circuiting of the motor by (1) a prescribed delay, (2) comparing the changing voltage level across the TRIAC (16, 116) and cutting the power off when the voltage level rises to a prescribed level, or (3) monitoring the decreasing speed of the motor to cut off the power when the speed decreases below a prescribed level.

Abstract: An emergency stop circuit for an elevator drive includes an emergency stop control (7) that selectively varies the current flowing in a field winding (4) of a direct current drive motor (M). During an emergency stop, the motor (M) operates as a generator and has an armature winding (1) loaded with a braking resistor (9) to apply a voltage, depending on the direction of movement of the elevator car, either by a first switch (10) and a second switch (11), or by a third switch (12) and a fourth switch (13). The switches (10, 11, 12, 13) are connected as an H-bridge between the windings (1, 4) and are controlled by the emergency stop control (7) depending on the deceleration required by the elevator car, for example by pulse operation depending based upon a preset deceleration value and a measured deceleration value from a deceleration sensor (14) mounted on the car.

Abstract: A method and apparatus for slowing back spin of a rod string of a progressing cavity pump powered by an electric motor when power is lost. Pulse direct current voltage into the windings of the electric motor powering the progressing cavity pump to magnetize a stator of the electric motor thereby reducing the rotational speed of a rotor of the electric motor and consequently the rotational speed of the back spinning rod string of the progressing cavity pump.

Abstract: A system is provided for controlling a DC motor which is constructed to propel a golf car. The motor is a shunt wound motor having independently excited armature and field windings. The basic input to the armature of the motor is supplied through a pulse modulated chopper circuit which varies the width of the pulse in response to the throttle of the golf car. Full control of the input to the field winding is gained by the supply of power to an H bridge circuit. Armature current is continuously sensed to provide an indication of the status and performance of the car during operation. At a predetermined level of armature current the field current is adjusted to provide a higher torque at a specific speed. When armature current indicates a predetermined overspeed condition, field current is adjusted to enhance regeneration and the resultant braking. In addition, the stopped condition is continuously monitored.

Abstract: A system is provided for controlling a D-C motor which is constructed to propel a golf car. The motor is controlled to provide performance according to a predetermined field current map which calls for a particular performance response to specified performance events. The performance events are detected by sensing actual speed and armature current and the performance response is triggered by adjustment of the field current. A performance map correlating actual speed to various events and specifying the field current response is designed for the motor used. In addition an armature current performance map is similarly constructed correlating armature current to particular performance events.

Abstract: A motor braking circuit arrangement, for use with a series/universal motor and a power supply for supplying power to the motor, including two separately actuable switches electrically interconnecting a separate braking winding with the motor to effect braking when either of the two switches are deactuated. The circuit arrangement includes a field winding wound about the motor stator and electrically connected in series with the motor armature winding. The separate brake winding is wound about the stator. The two switches are series-connected, and each switch is capable of assuming a first position associated with normal motor operation and a second position associated with motor braking wherein the separate brake winding is electrically connected in parallel with the motor armature. The switches may be single-pole, double-pole or combinations thereof.

Abstract: A series motor for an appliance or tool, such as a circular saw, includes a regenerative braking circuit having brake windings in addition to the run windings. One of the brushholder assemblies includes a push-away feature for separating one of the brushes from the commutator prior to the time the brush could wear to an extent that direct current reversal might not be available to achieve the desired braking action.

Abstract: A system is provided for controlling a DC motor which is constructed to propel a golf car. The motor is a shunt wound motor having independently excited armature and field windings. The basic input to the armature of the motor is supplied through a pulse modulated chopper circuit which varies the width of the pulse in response to the throttle of the golf car. Full control of the input to the field winding is gained by the supply of power to an H bridge circuit. Armature current is continuously sensed to provide an indication of the status and performance of the car during operation. At a predetermined level of armature current the field current is adjusted to provide a higher torque at a specific speed. When armature current indicates a predetermined overspeed condition, field current is adjusted to enhance regeneration and the resultant braking. In addition, the stopped condition is continuously monitored.

Abstract: A braking circuit for an electric motor includes a braking device for being connected in a circuit for braking the electric motor, a braking switch including first and second changeover switches for switching between a motor mode and a braking mode, and a control device. Switching contacts of the first and second changeover switches are switched between a first position for contacting, respectively, first stationary contacts of the first and second changeover switches in the motor mode, and a second position for contacting, respectively, second stationary contacts of the first and second changeover switches in the braking mode.

Abstract: Optimal constructions for two motor/controller configurations are disclosed. The controller structure includes an H-bridge for controlling field current using synchronous-rectification of MOSFET devices, and a circuit for chopping the armature current using synchronous-rectification of MOSFET devices arranged in a half bridge. The controller may be configured with a series-wound or a separately excited DC traction motor. In the series-wound motor/controller configuration, the field and the armature current are separately controlled. In the separately excited motor/controller configuration, the field of the motor is preferably wound so that the rated field current is achieved at about 20% of the rated battery voltage. This provides a separately excited motor in which the field current can be boosted by a factor of 5 to achieve high start-up and low speed torques which match the torque outputs of a series-wound motor under similar operating conditions.

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 dynamic braking circuit for a universal motor is disclosed. A switching mechanism is used to reverse the orientation of the series field winding with respect to the rotor when power is removed. Because the rotor acts as a generator when power is removed, it will generate current to the field winding. Because the orientation of the field winding has been reversed, the field winding will thus try to make the motor run in the opposite direction, thereby exerting a braking force on the motor. The amount of the braking force is limited by using a portion of a second winding to oppose the reversed action of the first winding.

Abstract: A method and apparatus for controlling a direct current motor of an elevator during emergency braking by conducting a current generated by the motor through a braking resistor are disclosed, in which a semiconductor switch connects the braking resistor across the motor during the emergency braking and a mains voltage to the motor is simultaneously interrupted.

Abstract: A speed control for a DC motor drive having regenerative braking and a field reversing control, has a field current feedback circuit which includes a modifier to change the feedback signal in accordance with the saturation curve of the field to provide a feedback signal representing field strength or field flux. Because motor field strength is regulated as a function of the required field strength, the control tends to make the speed of response independent of actual field strength. Also, a feedback signal is provided which is a function of the product of actual field strength and desired armature current, i.e., related to torque, and this controls the speed signal so that the gain of the speed regulating amplifier is inversely proportional to field strength. This allows drive operation at reduced field strength while maintaining the response.

Abstract: A propulsion system for an electrically driven traction vehicle includes a chopper, a d-c traction motor, and means effective when the system is operating in a motoring mode for connecting the chopper in series with the armature and the field windings of the motor to a d-c electric power source that includes a filter capacitor. Cyclically operative means provides periodic gating signals for alternately turning on and turning off the chopper, and it can be smoothly changed from a constant frequency, variable pulse width mode to a variable frequency, constant (minimum) off time mode so as to vary the "duty factor" of the chopper over a wide range extending up to 100 percent on time. Brake set up means is operative in response to a motoring-to-braking command for reconnecting the chopper in parallel with the motor and the filter capacitor and for reversing the polarity of the connection of the series field winding relative to the armature.

Abstract: A control circuit controls AC energization of a universal, series wound AC motor in a circuit breaker motor operator to power a breaker charging cycle. At the end of a charging cycle, the motor field winding remains energized from the AC source, however a braking resistor is switched across the de-energized motor armature to achieve dynamic braking. A timing circuit operates in the dual capacity of controlling dynamic motor braking and preventing continued running of the motor operator should the breaker operating mechanism fail to reset during a charging cycle.