Abstract: A system for simultaneously and independently controlling a plurality of electric motors from a number of dispersed stations. The system operates by transmission of duty cycle modulated selected frequencies superimposed on a DC track voltage on a common power line servicing the motors. The modulation is variable and determines the speed of the motors. Transmitters are portable and designed removably to plug into a common signal transmission cable anywhere along its length without interaction. Receivers, each tuned to a specific frequency and associated with and controlling a motor, are coupled to the common power line.

Abstract: Apparatus for controlling the pulse period of pulses applied to a pulse motor in a printer is disclosed. The pulse motor is accelerated by gradually reducing the pulse period of pulses applied to the pulse motor. After the detection of return of the printing head to a certain predetermined position, the speed of pulse motor is gradually decreased down by gradually extending the pulse period of pulses applied to the motor. At the start of returning movement of the printing head, the first pulse of pulses applied to the motor has a pulse period larger than that of self-start pulse of the motor. The pulse period of the subsequent pulses is gradually reduced. At the time of stopping the pulse motor, the pulse period of pulses applied to the motor is gradually extended to decrease the speed of the pulse motor. At the moment when the pulse period is extended to a value larger than the pulse period of self-start pulse of the motor, application of pulse to the pulse motor is stopped.

Abstract: The switching amplifiers of the prior art improved by a variable hysteresis in the comparator circuitry of said amplifier. Said variable hysteresis is controlled by the power supply voltage and a frequency sensitive feedback circuit. If the amplifier load creates an excessive frequency which cannot be controlled, a fault detector circuit disables the amplifier.

Abstract: A stepping motor (31) drives a load (33) such as an ink ribbon in a printer which exerts reverse torque on the motor shaft (32) thus displacing the shaft (32) slightly in the reverse direction when a low hold current is applied to a motor phase. Prior to switching the motor (31) to a next phase for rotation, a high drive current is applied to the present phase. After a certain length of time which is sufficient for the shaft (32) to be moved to the correct present position, the phases are sequentially switched while the high drive current is applied for rotating the shaft (32) and load to a new position.

Abstract: Control apparatus for an electric windshield wiper motor to permit a plurality of desirable windshield wiper system features to be realized including continuous and intermittent wiping operation with variable dwell, and coordinated manual or automatic wash and wipe operation. Some of the circuits implementing the control apparatus include a Zener diode and require only a single capacitor.

Abstract: There is provided a motor control system adapted for use, for example, with a sample analyzer, having means for generating signals representative of motor movement, and a logic circuit for analyzing the motor movement signals to determine increments of movement and the direction of movement. Digital circuitry is also provided for tracking the actual motor position as it is moved in either a forward or reverse direction, and comparing the tracked position with a programmed destination position. When and only when the motor is within a predetermined range of the destination position is a variable control generated, causing braking of the motor so that it stops exactly at the programmed destination position.

Abstract: An electronically controlled thread-cutting machine comprising a pulse controlled stepping motor for driving the thread-cutting tool, sensor means for scanning an adjustable thread depth and the torque on the thread-cutting tool, said scanning means comprising a counter for determining the steps of the motor and the number of revolutions of the thread-cutting tool respectively therefrom for determining the depth of the thread, and the current consumption of the motor being used for determining the torque transmitted to the thread-cutting tool, the motor being controlled in accordance with the torque and depth of the thread by micro-processor means for reversing the motor when the torque exceeds an upper limit torque and when the desired and preselected thread depth has been attained.

Abstract: A servo mechanism is illustrated which uses pulse pairs for positioning a motor by a given increment with a velocity sensing sample and hold feedback utilized to minimize detrimental repositioning forces. The velocity sensing is accomplished after the end of the drive pulses since this sensed voltage is proportional to the magnitude of the detrimental repositioning forces.

Abstract: A photoelectric transducer (14) produces first and second periodic signals (A), (B) which are 90.degree. out of phase with each other in response to rotation of a servo motor shaft (12a). The first and second signals (A), (B) are differentiated, directly full wave rectified and summed to produce a velocity signal (Vw-) having a magnitude proportional to the rotational velocity of the shaft (12a). The peaks of the first and second signals (A), (B) are detected to produce a reference signal (Vr) having a magnitude corresponding thereto. The magnitude of the reference signal (Vr) is reduced in accordance with the difference between the present position of the shaft (12a) and a command position to produce a velocity command signal (Vc+). The velocity signal (Vw-) is compared with the velocity command signal (Vc+), to produce a drive signal corresponding to the difference therebetween which is applied to the motor (12). Fluctuations in the amplitude, D. C.

Abstract: Solid state control devices are placed in series with each field winding of a step motor having a field for each of two phases. Each control device has a control terminal selectively permitting stepping drive current flow through the series field winding and gate means controlling each terminal. Sequence control means selects the sequence of application of control signals to respective gate means to determine the sequence and direction of drive. A timed current chopper means applies a timed signal to the gate means to determine when the control signal and what part thereof may be applied to the control electrode of the control device to control and adjust the drive effect. In this environment, sensing means is provided to determine when and how much current is flowing in a given field winding and to provide a signal to a comparator which is used in controlling the chopper. Various control circuits are provided for sensing and control in this environment.

Abstract: A reciprocating drive system moves a body of defined inertia, such as a carriage supporting electrostatic spraying means, at full speed between two points at which the direction of movement is reversed. The drive system includes an electric motor with polyphase stator windings and a squirrel cage rotor. Transducers responsive to the arrival of the moving body at the aforementioned points produce output signals controlling a phase switching system which reverses the direction of rotation of the motor. Reversal of the motor torque reverses the direction of movement of the moving body within a given travel and within a given time interval to full speed in the opposite direction. A stator current limiter provides positive coupling in an operative condition and no coupling in an inoperative condition with the motor running at full speed. The motor is selected so that the inertia of its rotor closely matches that of the moving body.

Abstract: In the process of aligning an image sensor (33) with a datum mark (23) on an artmaster (21), each of a plurality of elements of the sensor accumulate a charge based on the level of light sensed. The elements of the sensor (33) are repetitively scanned to obtain data pulses relating to the charges on the elements as an indication of the level of sensed light. Data pulses from selected elements of the sensor (33) are counted and compared to develop a signal representative of, and to facilitate visual indication of, the alignment or misalignment of the sensor (33) and the datum mark (23). If the sensor (33) and the datum mark (23) are misaligned, the developed signal facilitate control of servo motors (28 and 29) to move the sensor (33) into alignment with the datum mark (23). Data pulses derived from all elements of the sensor (33) are used to facilitate an electronic reproduction on a display board (40) of the position of the datum mark (23 ) relative to the sensor.

Abstract: Improvement in an electrical control circuit for controlling a D.C.

Abstract: Apparatus is disclosed for controlling the movement of a movable element to bring the movable element to rest at a desired stopping position.

Abstract: A method is disclosed for detecting the presence of a workpiece characteristic and controlling the sequence of execution of operational steps in a machining program. First instructions in a machining program cause a sensing element to execute a scanning cycle to detect workpiece characteristics. Second instructions in the machining program test for the presence of the workpiece characteristics to determine the next operational step to be executed. The next operational step may be sequentially located in the program or may be identified by third instructions which define a nonsequential program location. Jump instructions are also provided to execute an unconditional jump to operational steps defined by a jump location instruction in the program.

Abstract: The device comprises for each window an electric driving motor and a selector which is adapted to ensure the selective supply of current to the motor, in one direction or the other, through a control circuit acting on a supply source. The supply source is of the type capable of delivering at least two distinct energy levels. The control circuit comprises means for applying to an input of the supply source an energy level control signal which produces, as a function of the position of the selector, the application of a torque to the motor when raising the window which is higher than the torque applied when descending the window.

Abstract: Apparatus is disclosed for controlling the movement of a movable element between an initial starting position and a final stopping position. The apparatus comprises drive means coupled to the movable element and responsive to motor drive signals for moving the movable element along a predefined path between said starting and stopping positions; and first generating means for generating a first command velocity signal having a first state when the actual velocity of the movable element exceeds a predetermined value and a second state when the actual velocity of the movable element is less than the predetermined value.

Abstract: Probe method and means are disclosed for guiding and positioning a robot-actuated tool, such as a gripper or a welding head, through at least one transceiver for generating and sensing focused shockwaves, the probe being associated with the tool for relative movement with respect to the object or objects being sensed, without physically contacting the same.

Abstract: A control unit for automatically controlling the angular position of a reversible, motorized device, such as an antenna rotor, in response to a signal from an external sensor, such as a potentiometer coupled to the rotating shaft of a windvane. The unit includes integrated circuits and other electronic components for monitoring the windvane signal and for activating the rotor, as necessary, to maintain its alignment with the sensed wind direction. The unit also comprises means for providing: a no-response zone of adjustable width about the momentary, average wind direction; an adjustable, time delayed response to changes in wind direction; an automatic reversal of rotation if the rotor approaches the .+-.180.degree. position while searching for the wind direction; an automatic disabling of the rotor for windspeeds less than a selectable, threshold value.

Abstract: A method for controlling the transfer of a flexible web member from a supply reel to a take-up reel, according to which the rotational speeds of the supply reel and the take-up reel are measured and whereby the ratio between these measurements is established independently of the speed and direction of the movement of the web member. The method comprises the steps of storing reference information representing the characteristics of different types of reel and web, releasing the reference information corresponding to the reels and webs used, generating intermediate signals which represent the said ratio combining these intermediate signals with the released reference information and generating output signals in dependence upon the momentary position of the web in relation to one or other ends thereof, and using these output signals for the purpose of visually displaying the position of the web and/or of controlling certain operations of the apparatus.