Abstract: In order to minimize the current consumption of an alternating-current motor of the induction or the synchronous type (or possibly a plurality of such motors connected in parallel) driving a variable load, a sensor coupled to a supply line of the motor detects the occurrence of a significant change in its operating current and determines the sense of that change. A controller responsive to signals from the sensor then reduces the supply voltage by an incremental or decremental step and, if the sensor detects a resulting decrease in amperage, continues with one or more similar steps until the current levels off. If the initial voltage modification causes the current to rise, the controller progressively changes the supply voltage in the opposite sense until the amperage reaches a minimum.

Abstract: An overcurrent detection and protection device for stepping motors has means for detecting an overcurrent condition in the power supply to a stepping motor. Means responsive to the detecting means rapidly provides a signal to the stepping motor drive system causing the current to terminate and to remain terminated for a predetermined interval of time, at the end of which interval the device resets itself causing the current to resume. The device is sufficiently fast-acting to protect electronic components such as transistors.

Abstract: A disk drive control circuit designed to eliminate undesirable mechanical resonances that occassionally occur in the disk drive system as a result of a particular combination of seek commands. The control circuit uses an electrical model of the mechanical system in order to estimate or predict whether a particular seek command is likely to excite a mechanical resonance. The electrical model may be a filter network having frequency response characteristics similar to the mechanical system. The current used to drive a linear motor of the mechanical system is then applied to the filter network. The signal output from the filter network, which network effectively models the mechanical system, is thus representative of the mechanical response of the system upon performance of the seek operation. This signal output is monitored, and if it exceeds a predetermined threshold level, steps are taken to alter the system response so as to avoid exciting the mechanical resonance.

Abstract: Reproduction apparatus for producing multiple image simplex copies and/or duplex copies in a single pass of a copy sheet through the apparatus. The reproduction apparatus includes a movable imaging member upon which at least first and second transferable images are carried. Transfer apparatus is provided for transferring the transferable images from the imaging member to a copy sheet. A copy sheet positioning assembly is operable in synchronism with the movable imaging member and the transfer apparatus in first and second modes. In the first mode, the positioning assembly positions one side of a copy sheet in transferable relationship with the movable imaging member at the transfer apparatus to successively transfer the first and second transferable images to one side of the copy sheet.

Abstract: A stepping motor exciting system in which the excitation current is set at one of four stepwise values. When the motor is to be driven in a stepwise manner, the excitation current is in the form of a pseudo-trapezoidal wave which is derived in terms of two of possible four values. When the motor is to be driven in a linear manner, the excitation current is in the form of a pseudo-sinusoidal wave which is derived in terms of all four possible values. A ROM stores these sequences of excitation currents and controls the exciting system in accordance with the driving mode desired.

Abstract: A single phase alternating current electric motor is provided with a main stator winding having two coil groups each including the series connection of three coils. These coil groups can be connected in series for six pole operation and in parallel for four pole operation. The coils are approximately equally spaced around the periphery of the machine but are not of equal numbers of turns. The two coil groups are identically wound and spaced 180 mechanical degrees apart. One coil of each group has more turns and a greater span than the other two coils.

Abstract: Power window control apparatus for a motor vehicle window includes a motor actuatable to drive the window toward a predetermined position, an operator controlled actuator effective only during actuation to actuate the motor, a further actuator effective upon actuation of the operator controlled actuator for a time intermediate first and second predetermined time periods to maintain actuation of the motor after deactivation of the operator controlled actuator and an automatic deactivator effective to stop the motor and deactivate the further actuator when the window reaches the predetermined position. The window thus moves under operator control for very short or long movements but can be set to move under automatic control by actuation of the single operator control for a specified intermediate time duration.

Abstract: A windshield wiper control device for use on a vehicle includes a light-emitting unit mounted on the vehicle outside of a compartment for emitting a ray of infrared radiation, a photodetector unit mounted on the vehicle within the compartment and having a slit plate for producing an image of a striped pattern with bright and dark areas in response to exposure to the ray of electromagnetic radiation through the windshield and an array of photodetectors for sensing the bright and dark areas of the striped image and generating signals indicative of the bright and dark areas, and an arithmetic circuit arrangement for computing a contrast of the bright and dark areas based on the signals from the photodetectors and controlling the speed and/or period of operation of the windshield wiper based on the computed contrast.

Abstract: A combined ink cartridge/bubble removing device is detachably secured to an ink liquid supply system for an ink jet system printer of the charge amplitude controlling type. The combined ink cartridge/bubble removing device includes a housing having a bottom wall provided with an ink inlet portion and an ink outlet portion. An ink liquid tray is disposed in the housing near the middle height of the housing. The ink liquid tray has an inlet opening which is connected to the ink inlet portion via a vertically disposed pipe, and an outlet small opening for dropping ink liquid within the housing. Ink liquid collected by a beam gutter is introduced into the combined ink cartridge/bubble removing device through the ink inlet portion. While the ink liquid travels upward in the vertically disposed pipe, bubbles included in the ink liquid are removed, and the bubbles are discharged from the free surface of the ink liquid held on the ink liquid tray.

Abstract: An anti-skid brake system for vehicles is proposed in which various transducers for detecting operating condition parameters of the vehicle are provided, which cooperate with an evaluation circuit in such a manner that control signals are formed on the basis of the transducer signals for influencing the brake pressure at predetermined operating conditions. Circuitry are additionally provided which store the operating condition parameters, such as vehicle speed and deceleration, braking path and the like, during the braking event under the predetermined operating conditions; and to control marking of the road surface during these braking events.

Abstract: A printed circuit heatsink technique and assembly is disclosed which increases the heat dissipating capabilities of a printed circuit assembly. A thermally conductive plate is etched using the same artwork or mask employed to define the patterns of terminals and conductive areas on one surface of a printed circuit board. The plate is etched in those regions corresponding to the terminal and conductive areas so that holes are produced in the terminal areas and channels are produced in the conductive areas. The plate is then bonded to the printed circuit board prior to the attachment of the leads of electronic components through the holes formed in the thermally conductive plate. The assembly absorbs heat generated by the electronic components and provides a greater surface area for dissipating that heat without the need for specially fabricated heatsink elements or complex milling procedures.

Abstract: A direct current motor control circuitry provides linearity between an input signal to the circuitry and torque developed in the motor energized by the circuitry. A signal divider algebraically divides a numerator signal by a denominator signal and provides a quotient signal as the output. The input signal is provided to the signal divider as the numerator signal. A field circuit energizes the field winding of the motor. An armature circuit energizes the armature winding. One of the field or armature circuit provides a signal proportional to the respective one of field current or armature current to the denominator input of the signal divider. The signal divider is connected to the other of the field circuit or armature circuit for establishing the field current or armature current in accordance with the output quotient signal.

Abstract: The optical density pattern of an original document (26) is sensed during scanning movement for radiating a light image of the document (26) onto a photoconductive belt (27) which is held stationary during the scanning. Operating parameters of the apparatus (21) which are to be controlled after completion of scanning are computed as functions of the sensed pattern. Copy sheets of different sizes are provided, and the copy sheet size is selected to be equal to the sensed width of the document (26). Illumination lamps (37) are selectively energized to discharge non-image portions of the belt (27) between scanning and developing in accordance with the sensed dimensions of the document (26). A developing bias voltage is controlled in accordance with sensed document density and contrast.

Abstract: An apparatus for determining the common frequency w of two independently variable a-c quantities is described. In a rotating-field machine, the flux, for instance, is described by two electrical a-c quantities which together determine the magnitude and direction of the field. The two a-c quantities are variable independently of each other and the instantaneous direction of the field is given by an angle.alpha. according to the relation a.sub.1 /a.sub.2 =cotan.alpha., where a.sub.1 and a.sub.2 are the two a-c quantities. In order to determine the frequency of rotation w=d.alpha./dt of the field from these quantities, the quantities a.sub.1 and a.sub.2 are each fed to smoothing stages and thence to a computing circuit, wherein the quotient (d.sub.1 .multidot.a.sub.2 -d.sub.2 .multidot.a.sub.1)/(d.sub.1 .multidot.a.sub.1 +d.sub.2 .multidot.a.sub.2) proportional to the frequency is formed from a.sub.1 and a.sub.2 and the smoothed quantities d.sub.1 and d.sub.2.

Abstract: A motor driving a garage door is controlled by a controller, and the rotation of the motor in the normal and reverse directions is normally controlled in response to an actuating signal applied to the controller from a main push button switch. In a specific-mode in which an actuating signal is applied to the controller from an emergency push button switch, a mat switch or a fire sensor, the latter signal has priority over the former signal, and the motor is driven to move the garage door to its full-open position.

Abstract: The equipment for maintaining the spacing of track-bound vehicles (1) shall prevent collisions of the vehicles (1). For this, light emitters radiating rearwardly and laterally in desired directions are provided at the rear on the vehicles (1) and light receivers receiving from in front and from the sides in desired directions are provided at the front on the vehicles (1). A drive control reduces the speed of a vehicle (1) with increasing received light intensity, i.e. with decreasing spacing from the vehicle (1) travelling immediately ahead. The equipment is usable for floor conveying plants with vehicles (1) travelling at small spacings one behind the other. An embodiment of the equipment is suitable for vehicles (1) travelling forwardly and rearwardly. A further embodiment of the equipment is suitable for vehicles (1) on neighboring travel paths. Special measures are provided for compensation of the influences of ambient light.

Abstract: The invention relates to a control unit for a brushless D.C. motor having at least two stator windings controlled by semiconductor switching elements and a chopper. To avoid having extinguishing current pulses damage the chopper there is provided controls whereby the motor regulating waveform for controlling the chopper is effectively blocked during the active intervals of the extinguishing current pulses.

Abstract: The disclosure concerns a group supervisory control system for an elevator having statistical traffic data for the elevator from a past time interval and controlling the operation of the car dependent on the statistical data wherein the system comprises an operating apparatus which detects the distinction points of the variation of the traffic data to output traffic data and time for the distinction points as statistical data.

Abstract: A circuit for controlling the power delivered to a load from an alternating current source includes a bridge rectifier coupled to the alternating current source for developing full and half-wave rectified signals in response thereto. The full and half-wave rectified signals are algebraically added to form a reference signal which is applied to one input of a comparator, the other input comprising an adjustable direct current control signal. The output of the comparator comprises a pulse width modulated signal which is used to control the state of a switching transistor connected in series with the load between the rectifier node developing the full-wave rectified signal and a point of reference potential.

Abstract: A drive circuit for brushless direct-current motors having a cylinder-like air gap between a permanent magnetic inner or outer rotor and a stator, the stator windings being connected to a supply direct-current source in series with a respective feed transistor. The current flux depends on position signals from a semiconductor control element determining the rotor position, in particular a Hall IC, and on the switching state of a semiconductor switch responding to blocking of the rotor and serving as blocking protection for the stator windings. In order to avoid a thermal overload of the stator windings and of the semiconductor elements contained in the circuit, the semiconductor switch provided as the blocking protection is a transistor.