Abstract: A power tool including a braking and control circuit. The braking and control circuit includes a microcontroller-based control means circuit. The microcontroller assures control of switch means, such as triacs, switches and relays, and ensures that braking is effectuated regardless of the phase in the power cycle of the alternating current. Also, the microcontroller is programmable so that the braking and control circuit accommodates different braking conditions for different power tools and accommodates combinations of braking conditions for the same power tool. Further, the microcontroller is programmable to configure the braking and control circuit so that the braking force applied to the motor and the stopping time of the motor are regulated and adjustable. This may be accomplished by outputting a control signal so that the switch means skips cycles in the alternating current or by otherwise adjusting the operation of the switch means.

Abstract: An improved motor starter assembly is provided on a frame and having an external profile which matches that or is within that of a prior motor starter is disclosed. The improved motor starter assembly provides a soft start circuit within the profile. Retrofitting of prior art motor starters is accomplished by moving the power fuses and related hardware of an existing medium voltage (2.4 Kv to 7.2 Kv) and installing the new soft start circuit on the frame of the existing motor starter. The retrofitted arrangement mounts the motor fuses horizontally and the vacuum contactors vertically in an arrangement to provide enough space within the external profile to mount the soft start circuit arrangement.

Abstract: A circuit and method for braking a disk drive when a power fault occurs has a circuit (10) for producing an output signal (28) indicating that the motor of the disk drive has slowed at least to a predetermined rotational speed after the occurrence of the power fault. The components of the circuit (10) may be integrated onto the same integrated circuit as the motor driving circuitry or head retract circuitry. During the time between the occurrence of the power fault and the time the disk drive has slowed to the predetermined rotational speed, the read/write head mechanism (17) is retracted. A braking circuit then brakes the disk drive when the output signal (28) indicates that the motor has slowed, at least to the predetermined rotational speed. The circuit for producing an output signal indicating that the motor has slowed at least to the predetermined rotational speed is actuated by the back-emf (14) generated by the motor failing below a predetermined level.

Abstract: A method of diagnosing an electrically operated brake for abnormality thereof in an automotive vehicle wherein a wheel is braked by a friction force generated by an electric motor of the brake upon an operation of a brake operating member, the method comprising the steps of: applying an abnormality checking drive signal to the electric motor to operate the electric motor while the brake operating member is placed in a non-operated position; detecting a quantity relating to an output of the electric motor while the drive signal is applied to the electric motor; and determining that the electrically operated brake is abnormal, if the detected quantity does not normally correspond to a magnitude of the abnormality checking drive signal.

Abstract: A running gear for hoists and suspended loads has a running rail with two spaced-apart travel tracks that support axially spaced-apart running wheels. An electric motor is coupled to a self-locking worm gear for directly driving one of the running wheels. The running wheels are rotatably supported in a frame to which an assembly for hoisting suspended loads is secured. In order to prevent the running gear from rolling and pitching during braking, which can cause increased wear of the running gear and the running rail, a control unit is provided which is operatively connected to the electric motor and determines a start-up rate during the start-up phase of the motor from an average increase of the motor torque as a function of time, and decreases the motor torque as a function of time at a slower rate than the start-up rate for slowing down the running gear.

Abstract: A device for protecting a braking resistor for locomotives supplied with AC power obtained by chopping the DC voltage from the power grid comprising at least one pack of resistive components of the resistor which has at least one reference resistive component which is made of a different material than the other resistive components of the pack but is suitable to react thermally in the same manner as the other resistive components of the pack when it is crossed by the same current, and a control circuit which is associated with the pack of resistive components and is suitable to detect their temperature by detecting the variations in the electrical characteristics of the reference resistive component.

Abstract: The invention relates to a method for enhancing the dosing precision of a dosing pump which is driven by an asynchronous motor via an eccentric gear. The supply of the motor is cut off approximately half a cycle time before a desired dosing pause period or stoppage. The motor freewheels afterwards for part of the cycle time, before a direct voltage is applied to it for approximately a quarter cycle time, such that an eddy current is induced in the rotor, which produces an antipolarized magnetic field which brakes the rotor.

Abstract: A method and apparatus are disclosed for controlling regenerative energy from an induction motor. The induction motor is connected to a battery, which is intended to capture the regenerative energy of the induction motor. Normally, the induction motor is operated at peak efficiency, to capture as much energy as possible. However, when the battery becomes nearly fully charged, the induction motor is operated at reduced efficiency to prevent overcharging of the battery. The operating point of reduced efficiency of the induction motor is a point at which electrical losses are relatively more located in the stator of the motor than in the rotor of the motor. The stator of an induction motor is generally better cooled than the rotor.

Abstract: A double pole, double throw switching arrangement for effecting dynamic rotor braking of user controlled operation of a reversible direct current servo motor. Two columns of stationary center and oppositely disposed side contacts are disposed in spaced parallel arrangement on the switch base. One side contact in one column is connected to the opposite side contact in the other column and to the B+ supply. The remaining side contacts in each column are connected to a ground strap having a portion disposed for wiping contact. A pair of commonly user actuated moveable contact members are disposed for sliding contact with each column of contacts. The center contact in each column is connected to one end of a separate forward and reverse motor coil. In the neutral position both motor coil contacts are grounded. User movement of the common actuator in one direction simultaneously causes the moveable contact members to keep one motor coil grounded and connect the other motor coil to B+.

Abstract: A tricycle with an electric motor in which two rear wheels 4 and 4 are driven by not only an electric motor 5, but also pedals 6 with manpower. A rotational force of the pedals 6 is transmitted to drive shaft 9 via first bevel gears 8a and 8b and then transmitted to a one-way clutch 7 via second bevel gears 10a and 10b from the drive shaft 9. The output of the one-way clutch 7 is then transmitted to the two rear wheels 4 and 4. The electric current to the electric motor is a pulse current and its pulse width is controlled to be shorted in relation to a braking operation.

Abstract: A disk drive employs a method of operating a spindle motor to respond to a spin-down command to reduce the time required for spinning down and subsequently spinning up the spindle motor. The disk drive is connectable to a power supply having a fixed DC voltage. The spindle motor includes a stator having a plurality of windings and a rotor rotatable at a variable spin-rate. The rotor has an angular position relative to the stator. The disk drive includes switching elements coupled to the fixed DC voltage and the plurality of windings. The switching elements are controlled to sequentially apply the fixed DC voltage across a selected combination of the windings to generate a negative torque on the rotor such that a controlled braking operation is performed to decelerate the rotor to a selected spin-rate .omega.1. After the variable spin-rate is reduced to the selected spin-rate .omega.

Abstract: A method and a device for electrical braking of an all-mains motor by which disconnection of supplied feed current to the motor causes an electric switching operation, whereby electric current arranged to cause a reversed rotary direction for the rotor (1) of the motor is supplie. According to the invention, supplied braking power (P) is controlled and reduced on basis of the successive reduction of rotary speed for the motor until the rotor (1) of the motor has substantially completely ceased to rotate, preferably substantially corresponding to an inverted "soft start" for the motor, whereafter supplied braking current feed is interrupted. It is advantageously monitored whether or not normal start of the motor has been performed, electric switching to braking only being made possible provided that such a start sequence has been indicated.

Abstract: The present invention relates to a control circuit for motor of electric jogging device in which a safety switch is disposed between an electronic loop and a power switch and which has an inserted safety plug-in pin to connect the power in an ON state. Accordingly, when the safety plug-in is removed from the fastening position, the second safety switch will be shut down in an OFF state so that the power won't enter into the electronic loop again and the motor won't be driven, and the safety of the user can be ensured.

Abstract: A hand held battery powered tool having a motor with a rotor within a stator having stator windings and a motor control trigger operably movable between off and enable positions with means for sensing the trigger position and proving an output signal indicating trigger movement to the off position and means responsive to the output signal for shorting the motor windings and dissipating the kinetic energy of the rotating rotor as heat. A method of retarding rotation of the rotor of the motor comprising the steps of sensation of motor operation command and shorting the motor windings upon sensing the motor operation command while continuing electronic commutation of the motor windings is also provided.

Abstract: An electromechanical actuator is adapted to be connected to an external device for displacing the external device to a predetermined position and maintaining the external device at that position. The actuator includes a housing which holds a drive motor for driving the external device to the predetermined position when the motor is energized and a brake mechanism for maintaining the external device at the predetermined position when the brake mechanism is activated. A switching device generates switching signals for energizing the motor to drive the external device to the predetermined position and for de-energizing the motor and activating the brake mechanism when a predetermined time has passed from a moment the drive motor is energized, to maintain the external device at the predetermined position.

Abstract: The wheel brakes of each vehicle axle or side or diagonal are supplied with current by a separate voltage source. To reduce the load on the vehicle's electrical system, the wheel brakes of a front axle are supplied with current first, and then the wheel brakes of a rear axle are supplied with current.

Abstract: The invention concerns a frequency converter for an electromotor with an intermediary circuit, in which a braking circuit with a switch and a load is arranged. With such a frequency converter, it is possible to ease the demands on protection measures, even though the load is placed outside the frequency converter. For this purpose the load is galvanically separated from the intermediary circuit.

Abstract: A system and method for evaluating the effectiveness of a tractive effort maximizing control system in a wheeled vehicle utilizes a process of operating the vehicle by applying controlled power to at least some wheels of the vehicle to enable motion of the vehicle, disabling the tractive effort maximizing control system, and varying creep speed between a minimum value and a selected maximum value while monitoring the tractive effort to identify a maximum available tractive effort. Thereafter, the tractive effort maximizing control system is enabled and the resulting tractive effort developed by the vehicle measured. Comparing the resulting tractive effort to the maximum available tractive effort produces a measure of effectiveness of the tractive effort maximizing control system.

Abstract: A control apparatus for a motor-driven vehicle driven by a motor brakes the vehicle without giving shock to the vehicle. The control apparatus includes a vehicle maneuvering section for sensing a manual driving force as applied to it. The control apparatus also includes a control circuit which, when a manual driving force for driving the vehicle is applied to the maneuvering section, causes the motor to provide a mechanical driving force for the vehicle in accordance with the sensed manual driving force. The control circuit includes a braking force providing device which gradually increases a braking force for braking the vehicle from zero when manual driving force has been removed from the maneuvering section.

Abstract: A wheel brake operated by electric motor for motor vehicles, where the operative braking forces and braking torques as well as the actuator control signals are determined for each wheel brake by appropriate measuring equipment. On the basis of these signals, implausible deviations are detected by comparison, and the faulty signal is recognized and treated appropriately by using the corresponding signals of the other wheel brake of the same and/or the additional axle(s).

Abstract: An electronic brake system for a vehicle which has control modules for adjusting the braking force at the wheels of the vehicle, a control module which determines at least the driver's braking command, and at least one communications system which connects the modules to each other, where, to supply the elements with energy, at least two independent vehicle electrical systems (E.sub.1, E.sub.2) are provided, at least one of the elements being connected to an electrical system different from that to which the other elements are connected.

Abstract: A spindle motor control method stops a spindle motor which rotates in a forward direction in response to a rotation signal. The spindle motor control method includes two steps. First, a brake signal is supplied to the spindle motor for rotating the spindle motor in a reverse direction when stopping the spindle motor which rotates in the forward direction. Second, the rotation signal and the brake signal are put in an OFF state when a frequency generator signal FG, which indicates a rotational phase of the spindle motor and is generated based on an output of the spindle motor, is not detected for a predetermined time.

Abstract: A control circuit (10) is provided for an electric motor brake (12) having an electromagnetic brake coil (14) energizable to actuate the brake to a released condition permitting rotation of an electric motor (16), and de-energizable to enable actuation of the brake setting the brake to a braking condition stopping rotation of the motor. The control circuit includes a switch (102) having an on state energizing the brake coil, and an off state de-energizing the brake coil.

Abstract: A braking system consisting of coil assemblies (6) which move in relation to a rotor magnet assembly (9) by using an actuator assembly (2). As the coil assemblies (6) are moved closer to the rotor magnet assembly (9), a current will develop in the coil assembly (6) which will generate a magnet field. This magnet field will in turn induce a torque on the rotor magnet assembly (9). The developed current can then be used to recharge the onboard energy storage system.

Abstract: An electric drive for the vehicle or traveling mechanism of a lifting appliance contains a control which controls the switching on of the mechanical brake and the switching of the motor current off and on again. In this case, there is provision, in the event of a changeover from a high traveling speed to slow maneuvering speed, for the mechanical brake to remain released until the maneuvering speed is approached. During this phase, the vehicle is decelerated solely by the internal friction and the rolling friction on the rail, in order to avoid inducing any or any additional load pendulum oscillation.

Abstract: A controller for controlling supply of electrical current to the coils or coil groups of an electromagnetic retarder for applying drag torque to a turning shaft or drive line. The controller includes an input signal receiving element for receiving input signals from at least one input device, a control unit responsive to the input signal for modulating electrical current supply from at least one current source to the retarder coils so that current is distributed to each of the coils or coil groups substantially equally.

Abstract: A current regulator is disclosed which utilizes a well known driver chip. The driver chip has an input signal known as a brake signal "BRK" which typically is used to stop a standard DC motor. In this invention, the brake signal "BRK" is used to create a low resistance current path in order to sustain the current of the current regulator which is used in conjunction with a stepper motor.

Abstract: A wheel slip recovery method for a locomotive in which an internal combustion engine is connected in driving relationship to an electric power generator to supply electric power to a plurality of electric traction motors coupled to drive corresponding wheel-axle sets of the locomotive. The locomotive system includes a dynamic braking function in which an electrical resistance circuit is selectively coupled in parallel circuit arrangement with the generator for selectively receiving power from the traction motors during dynamic electrical braking. The inventive method detects a wheel slip condition which cannot be overcome by transfer of power from a slipping to a non-slipping wheel and selectively couples the dynamic braking resistance circuit into circuit with the power generator in a manner to reduce power supplied to the driven wheels to a level sufficient to allow the wheels to cease slipping without reducing power output from the generator.

Abstract: When a voltage level determinator judges from the terminal voltage of a smoothing capacitance that a battery is in an over-charged state and cannot receive regeneration energy, a regeneration/free-wheel mode selector switches to a free-wheel mode for consuming the energy of the battery. For this purpose, a torque reducing signal generator executes a control in which only a magnetizing component of current flows through the primary winding and no driving force is generated in the motor, with the result that the energy of the battery is consumed as heat loss inside the motor. Then, when the over-charged state is eliminated and the energy receiving capability of the battery is recovered, the regeneration/free-wheel mode selector switches the mode to the regeneration mode to obtain regeneration braking.

Abstract: According to the invention, when directed to slow down a driven device, the speed of a driving motor is reduced from a first speed to a slower second speed. In this state, a driving gear continues to rotate at said second speed, whereas a driven gear continues to rotate by inertia and gradually slows down from said first speed. Thus, the rear of a cog of the driven gear is separated from the front of a cog of the driving gear. When the speed of the driven gear is equal to the second speed, i.e., the speed of the driving gear, the front of another cog of the driven gear reaches the rear of said cog of the driving gear. Accordingly, both gears lightly make contact. Thereafter, the driving motor is rapidly braked by maintaining the contact of the driving gear and driven gear such that both gears slow down and stop.When slowing down a driven device, noise generated by the impact of both gears is reduced as much as possible, and the time for slowing down a driven device is reduced.

Abstract: An electrical system that receives power from an external power source that includes an inverter (U1). The inverter (U1) receives DC power and generates a variable voltage output. First and second current collectors (30, 32) connected to the inverter (U1) and receive the DC input through contact with positive and negative poles of the external power source. A motor (M1) and an internal DC bus (+,-) are connected to the current collectors (30,32). A protection circuit is connected across the internal DC bus (+,-), and protects the inverter (U1) from connection to an input of improper polarity. The protection circuit permits the inverter (U1) to deliver a DC output to the power source during a regenerative braking operation.

Abstract: A series motor has a braking device, a stator having a field winding and a pole shoe plate pack, the pole shoe plate pack of the stator having field coils and also having a further element inducing a magnetic field, a rotatable armature, and an element for influencing a braking operation of the field winding.

Abstract: A method and device for controlling the torque of a brushless DC motor used in an electric motorcycle, in which a single current loop is employed to obtain a feedback current by a current detector from a DC bus which simplifies the construction of the circuit scheme. The device of this invention operates by two input signals; one of them is a torque command signal to generate a positive torque of the motor, and the other is brake command signal to generate a negative torque of the motor so as to operate a control brake command and to store the energy generated during a braking operation into a battery of the motorcycle, as well as to stop the rotation of the brushless DC motor within 120.degree. of its electrical angle of reversed rotation.

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: A recording medium library system retaining up to a predetermined number of cartridge type recording media for recording/reproducing data on the recording medium is disclosed. The recording media are stored in a plurality of cells provided in a cell drum. The cell drum is rotatably driven such that a desired cell is brought to a target position. In the driving, an accelerating current, a braking current, and a positioning current are supplied to the motor in order of mention. At least the braking current is determined according to an input value of the inertia of the cell drum.

Abstract: An apparatus for measuring at least one state variable of a brushless direct-current motor includes 2 * n pole segments, wherein n=1, 2, 3, etc.. The pole segments are integral with a rotor of a brushless direct-current motor and are formed of permanently magnetic material generating a magnetic field. At least one Hall-effect element supplies an output voltage and is disposed in the vicinity of the rotor for impressing the magnetic field of the permanently magnetic segments on the output voltage from the at least one Hall-effect element. A logic unit receives the output voltage from the at least one Hall-effect element for determining the temperature of the brushless direct-current motor.

Abstract: In an AC inverter drive connected to an AC induction motor on a material handling machine, the motor (which has a load holding brake and a pulse-emitting shaft encoder) moves a load in hoisting or lowering directions. A method for checking brake load-holding torque including the steps of decelerating the motor toward zero speed, setting the brake, applying "float" load-holding electrical power to the motor, changing the current flowing to the motor and checking for motor rotation by pulse-counting. Motor power is blocked if the number of counted pulses is less than a predetermined number or is increased if the number of counted pulses is greater than a predetermined number, the latter indicating that the brake is incapable of holding the load.

Abstract: A control device for a parking brake for a vehicle includes an electric motor which rotates a crank to activate the parking brake with the provision of a disk having two concentric conductive tracks which are interrupted by an insulating space; the disk is rotated by the drive shaft to control the supply of current for driving the electric motor.

Abstract: A motor drive circuit, in which a first transistor at a drive stage, a second transistor at an output stage to be driven by the first transistor and a third transistor downstream the output stage for a short braking operation are formed in a common substrate or a common well of the substrate, a region of either a P type or an N type in either the substrate or the well is connected with the first transistor via a conductor so that a parasitic transistor is formed in which the substrate or the well serves as its base, whereby a current flowing from the first transistor to the second transistor during the short braking operation is sinked by turning on the parasitic transistor.

Abstract: A positioning control for linearly displacing an object (31) has a direct current motor (1) and a gear (2,21) for converting rotary into linear motion, a current supply (4) of current pulses having given frequency, amplitude and duration; a pole reverser; a rotatable operating element (51) coupled to an angular step generator (5) and a sensor of the sense of rotation. The pulse frequency of the current supply (4) is determined by the angular step generator (5) and the polarity of the pole changer is determined by the sensor of the sense of rotation. The characteristic curve of the speed of displacement of the object (31) as a function of the pulse frequency is kinked, in that for low pulse frequencies the speed increases proportionally slowly, and up from the level of a pulse frequency threshold, the speed increases markedly quicker. The invention is useful for microscope focussing drives.

Abstract: Apparatus for fitting a motor vehicle tire on a disc wheel comprises a tire fitting tool mounted rotatably about an axis, an electric drive motor to drive the tire fitting tool about the axis, a current supply means for the drive motor, and a torque limiting means to terminate the rotary drive to the motor when a predetermined torque transmitted to the tire fitting tool is exceeded, thereby to protect the tire from overloading in the fitting operation.

Abstract: A motor brake control circuit is provided with a coil short circuit for short-circuiting the power terminals of the coil once a brake signal is issued from its brake circuit so that the brake is forcibly and continuously applied to the motor. With such an arrangement, the time required for the motor to come to a complete stop after the issuance of a brake command signal is considerably reduced as compared with a motor that does not have such a coil short circuit and, therefore, comes to a complete halt only by natural deceleration. Further, since the motor is braked by the short-circuited motor coil when the brake control circuit is activated, there is virtually no affect on the motor by external force such as vibration to shift its rotary position in a braked condition.

Abstract: A method for determining operability of a dynamic braking system in an electrically propelled traction vehicle by cycling selected switching devices while the vehicle is at rest and measuring voltages and currents generated in response to operation of the switching devices. In one form, the dynamic braking system is operated to be connected to a power conversion system of the vehicle and the voltage developed at the braking system compared to the voltage coupled to the vehicle. Using prior knowledge of system resistances, calculated ideal values of voltage are compared to measured values to confirm proper system operation. Malfunctions of particular components are logically determined by ratios of measured to ideal values and by operation of selected ones of the switching devices.

Abstract: A compact surgical handpiece comprises a motor energizable for moving a tool member, electric energy supply actuable for energizing the motor and a manually actuable trigger actuable to control motor operation. A motor control circuit interconnects the motor electric energy supply and trigger for running and braking the motor in response to actuation and release of the trigger. The control circuit includes a compact regulated voltage supply, a motor overcurrent limiting feature and a motor braking feature which is effective even if the operator fails to fully disconnect the electrical supply to the motor upon releasing the trigger.

Abstract: An improved electrical circuit configuration for a chopper circuit is disclosed which is particularly adapted for use with an inductive load such as a braking resistor of the type used in many rapid transit vehicles. Instead of connecting a di/dt reactor directly in series with the electronic switch of the chopper circuit, a di/dt reactor is connected in series with the freewheeling diode. Using this configuration, the di/dt reactor does not have to continuously handle the average current through the electronic switch during the entire chopping operation. Hence, a much smaller, lighter, and less expensive di/dt reactor can be utilized.

Abstract: A control arrangement for protecting the control circuit for a self propelled, automatically controlled wheeled vehicle having spring applied, electrically released brakes, to enable the vehicle to be manually pushed without damage to the vehicle control circuitry by generation of currents by the DC motors, the arrangement including a manually operable switch disconnecting the DC drive motors from the vehicle control circuit while simultaneously energizing a brake release actuator.

Abstract: A rotor speed adjustment circuit (60) reduces the rotational speed of an anode (32) of an x-ray tube (14) in a diagnostic apparatus (10). An AC current (64) from an AC current source (54) is applied to one stator winding (52). A parallel connected diode (70) and resistor (72) are connected between the current source and a second stator winding (50) to cause an effective DC magnetic braking component (66b) which reduces the rotational speed of the anode and an associated rotor (42). By selectively adjusting the resistor (72), the size of the DC magnetic braking component, hence the amount of effective drag is selectively adjustable to adjust the anode rotation speed.

Abstract: A motor rotation control device furnished with a rotational detector for detecting the rotation of the motor and actual rotation direction detecting means for obtaining the actual direction of rotation of the corresponding motor on the basis of the rotation detection signals of the corresponding rotational detector and so composed that reverse drive force can be given to the corresponding motor by changing a commanding signal for appointing the direction of rotation of the corresponding motor when changing the direction of rotation of the corresponding motor or braking the motor, wherein any error of the motor rotation control device can be instantaneously detected, without waiting until the above actual direction of rotation of the motor becomes coincident with the rotation commanded direction after changeover, even right after the rotation commanded direction of motor by a commanding signal has been changed.

Abstract: A fail-safe variable damping suspension system for a motor vehicle controls the oscillatory spring movements of each wheel via a permanent magnet rotary electric machine which is connected to machine control circuitry by normally open contacts of a relay. In the event of failure of the suspension system, the relay is released and the machine takes the form of a permanent magnet alternator which is connected to a defined load via normally closed contacts of the relay. Thus, in the event of a failure of the suspension system, the machine control circuitry is disabled and all shock absorbers are set to a fail-safe mode by the defined load upon closure of the normally closed contacts of the relay.

Abstract: In a 2 pole universal motor for a circular saw a secondary winding provides dynamic braking. Both run and brake windings are split electrically with respect to the armature. All windings are double-ended and wiring and winding is arranged so that all windings may be terminated directly to fixed termination points, four at each end of the stator, providing for axially oriented plug-in connection of brushes at the commutator end and switch and line at the fan end. There are no jumpers within the stator.