Abstract: A device for providing protection to a battery utilized as an auxiliary and starting power source for a motor-generator. The device includes a switch positioned intermediate the battery and the load and circuit means for integrating current flow from said battery when said generator is inoperative and automatically opening the switch when the product of said integration reaches a predetermined threshold level. The device is particularly adapted for a vehicular battery and uses a length of the battery cable for detecting current flow.
Abstract: The invention is an improved control mechanism for winches as used on cranes and similar devices having a single motor driving the shaft of a winch drum through a pair of eddy current clutches. Gear trains attached to the two clutches are operative to drive the drum's shaft in opposite directions. An electronic control generates an output signal indicative of a commanded speed and direction of drum rotation while a tachometer generates a signal indicative of the actual speed and direction of drum rotation. The electronic control system compares the commanded and actual speed as well as the direction of rotation and generates signals energizing the two clutches. The combined action of the two clutches stabilizes the rotational speed of the drum and its direction of rotation in accordance with the commanded input.
Abstract: A control apparatus for driving a pulse motor which receives from a computer or the like a command signal indicative of the number of drive pulses to be applied to the pulse motor within a given time interval in order to drive the pulse motor at a given rotating speed produces, in response to the command signal, drive pulses equal in number to the commanded number within that time interval, preferably with uniform distribution, and drives the pulse motor in accordance with the drive pulses.
Abstract: A control device for electronic apparatus is provided with a d.c. ironless motor coupled to a manually rotatable knob. As the knob is rotated a digital signal representative of the rotation is derived from the back e.m.f. of the motor.
Abstract: A high vacuum turbomolecular pump is described incorporating a drive system which significantly reduces the amount of heat build-up therein. The pump includes an outer casing having an upper open end adapted to be communicated hermetically with an isolated environment to be pumped, and an exhaust opening at its lower end. A plurality of vertically spaced stator blade wheels are positioned within the casing intermediate the inlet and exhaust openings, and a rotor is mounted within the casing on a spindle for rotation therewith on a generally vertical axis. The rotor is provided with a plurality of axially spaced rotor blade wheels interleaved with the stator blade wheels. An electrical induction motor is incorporated into the pump with its rotor output shaft being the spindle so as to rotate such spindle and, hence, the pump rotor for high vacuum pumping.
Abstract: A stepping motor control circuit incorporates two sources of pulses for driving a stepping motor, one of which has a frequency greater than the maximum frequency which the motor can follow. A pair of shift registers are used for effecting acceleration and deceleration of the stepping motor, when the high frequency pulse source is used. A first shift register stores an acceleration pulse sequence, to supply pulses to the stepping motor at an increasing rate, after which pulses are supplied directly to the stepping motor from the high frequency pulse source. The second shift register is energized to apply deceleration pulses to the stepping motor. Pulses having a relatively low frequency are supplied directly to the stepping motor when only a small motor movement is required.
Abstract: A mining machine includes drive unit means for driving a haulage winch and a cutting tool of the machine, the drive unit means comprising a multi-phase induction motor with a wound rotor. In order to control the motor speed, the motor is provided with a circuit connected across the rotor windings and means for varying the effective impedance presented by the said circuit to the rotor windings.
Abstract: Electrically operable switching circuitry is effective to energize, in response to the application of a control signal, a commutated electrical motor in a first direction for driving a member driven thereby through a travel stroke and to energize, in response to the removal of the control signal, the motor in a second direction for driving the member driven thereby through another opposite travel stroke and an electrical signal produced while the motor is in the run mode is effective to maintain the switching circuitry operated for motor energization. Upon motor stall when the member driven thereby has reached the end of a travel stroke, the electrical signal produced while the motor is in the "Run" mode terminates and the switching circuitry then operates to deenergize the motor.
Abstract: A proximity switch is connected to close a circuit between a source and a load when a metal object is adjacent to a coil in the switch. The coil is part of an oscillator circuit that is selected to have its output damped below a selected amplitude when the metal object is close enough to the coil. The reduced amplitude of oscillation opens a capacitor shunting switch thereby permitting the capacitor to be charged. The charging of the capacitor to a selected level turns on an SCR to connect the load to the source through the SCR. A power storage circuit has a capacitor that is charged when the SCR is turned off to provide operating current for the circuits of the switch when it is not available because the SCR is turned on to shunt the current from the main power source.
Abstract: An electric motor arrangement in which a modified induction motor is operated as a three-phase motor by connecting one of the input phases to the junction of the two motor windings, and by connecting the other two input phases to the other sides of the two motor windings. In one embodiment of the invention, one of the input phases is connected to the junction of the windings through a centrifugal switch. The induction motor may be a modified version of a permanent-split-capacitor type wherein the motor capacitor, conventionally connected across the free ends of the windings, is removed.
Abstract: Linear and rotary stepper motors are provided with predetermined stop positions which differ from the magnetically inherent stepped positions of the stepper motors. The predetermined stop positions result from sensing the distance the rotor or slider is from a predetermined stop position and generating a signal including a position component representing the distance to the stop position and a velocity component representing the velocity at which the stop position is being approached. The signal is in turn utilized to generate a current reference signal for the motor which is compared with the current of the motor so as to stop the motor at the predetermined stop position.
Abstract: A control circuit for operating a stepping motor from a DC power source by switching current successively through four stator windings. Switching time in relation to shaft position is controlled by sensing the back EMF in the stator coils, the sensing circuit including a transformer having a first winding connected in series with two windings and the second winding connected in series with the other two windings of the stator. The voltages across the two windings at the transformer are used to generate a commutation pulse each time the voltages are equal. Each commutation pulse is generated in this manner at predetermined angular positions (phase) of the stepping motor independently of motor speed or supply voltage. The commutation pulses are then used to generate clock pulses for sequencing the switching of the stator windings.
Abstract: Apparatus is provided for digitizing a pattern by utilizing the computer controller and motor driver of an x-y table used in an automatic sewing machine. A manually operated control stick is installed on the machine and connected through the controller to send command signals to the motor drivers. A viewer is mounted on the machine to project a pattern, which is placed on the work surface of the x-y table, onto a small screen. The operator may then, through the use of the viewer and the control stick, move the x-y table through the desired pattern. Such movement is recorded in the computer for use in generating a control tape for the specific pattern.
Abstract: Improved door activating motor control apparatus employs a self latching safety edge relay which is selectively energized by any of "open", one-button universal or obstruction-sensing safety edge contacts. A motor controlling contactor switch has its "open" direction coil and contact portion operated by safety edge relay contacts, and its "close" relay portion operated under control of a "close" or the one-button switch.The composite control apparatus of the instant invention exhibits significant operational advantages over prior art structures including, inter alia, frequency exercise of safety edge relay contacts, responsiveness to the "open" switch in an emergency situation, and retention of an obstruction sensing signal to cause door opening.
Abstract: A controlled bi-directional motor is energized through a power switching arrangement of the type electrically operable in a manner to energize the motor for rotation in one direction and in another manner to energize the motor for rotation in the opposite direction. Circuitry including a single pole-single throw electrical switching device is responsive to the operation of the switching device electrically open to operate the power switching arrangment in the manner to energize the motor for rotation in a first direction and other circuitry also including the electrical switching device is responsive to the operation of the electrical switching device electrically closed to operate the power switching arrangment in the manner to energize the motor for rotation in the opposite direction.
Abstract: A controlled bi-directional electric motor is energized for armature rotation in respective opposite directions in response to the operation of an electrical control switching arrangement electrically open and electrically closed. A mechanically operable electrical switching device arranged to be operated by a mechanical movable member that is driven between first and second travel limits by the controlled motor is effective, when the movable member is driven by the motor to either travel limit, to interrupt motor energization and to condition the circuit for effecting motor energization for armature rotation in the direction to drive the movable member toward the other travel limit.
Abstract: A combined cycle electric power generating system which drives two electric power generators at a constant speed. It employs a gas turbine to drive one of the generators and a steam turbine to drive the other. There is a combustor that supplies the gas to drive the gas turbine and there is an air compressor that feeds input air to mix with fuel into the combustor. The compressor is driven by the gas turbine. The exhaust from the gas turbine delivers heat to make steam for the steam turbine. And, there is means for throttling the inlet air to the compressor so that the whole system may be run at greatly reduced load without creating inefficient operation.
Abstract: This invention relates to a driving signal control circuit, in which at least four detecting points (or detectors) are arranged for detecting the position of the working table, which is repeatedly reciprocated between the detecting points.
Abstract: During machine tool operation a first set of sensors, referred to as cutter deflection sensors, provides data which is representative of the physical deflection of the cutting tool from a rest position, while a second set of sensors, referred to as position sensors, provides data which is representative of the position of the workpiece mounted on the machine tool relative to a reference or setpoint position. The cutter deflection and workpiece position data are combined to produce a resultant which is representative of the actual position of the cutting tool relative to the workpiece. This resultant is then compared with reference data which is representative of the desired position of the cutting tool relative to the workpiece. The difference between the actual and desired positions is then compared with a preselected tolerance value.
Abstract: A drapery opening and closing system is provided for draw drapes which are movable over a traverse member between an open and closed position by use of a drape drive system. The opening and closing system has limit switches positioned to be activated when the drapes are opened and closed. A manually settable timer connected to a power source applies power at preset times to a reversible motor via a control circuit. The control circuit is comprised of a relay activated by the timer and a series connected two-section switch. Outputs of the two-section switch are connected to the reversible motor through the limit switches. When the timer is triggered at a preset time, the drapes automatically open or close. Via the two-section switch, the drapes may be manually activated to open or close at times other than the preset times on the timer.