Abstract: A power-on-reset circuit with power fail detection, comprises a supply voltage V, and a voltage divider comprising two series resistors connected between V and the ground. The junction between the two resistors is connected to the (+) terminal of a voltage comparator. The junction is also connected through a diode to the (-) terminal of the comparator. The (-) terminal is also connected to ground through a capacitor and resistor in parallel. A resistor and compacitor in series are connected between V and ground and the junction between the resistor and the capacitor is connected to the output of the comparator, and also to the input of an inverting gate. The output of the inverting gate is the power-on-reset terminal.

Abstract: Apparatus for removably supporting and electrically grounding a cover to a base structure, having an upper and lower attachment assembly, the lower assembly having a hanger with a horizontal portion and an integral vertical portion, a leaf spring of inverted V-shaped configuration with a vertical leg affixed to the base structure and an angular leg extending to normally resiliently engage the hanger vertical portion, a lower bracket affixed to the cover having a horizontal leg and an integral vertical portion at the leg outer end, the horizontal leg having an opening to receive the hanger vertical portion, the upper assembly having a hanger with a horizontal portion with an opening therein, a leaf spring of inverted V-shaped configuration having an angular leg extending downwardly through the opening, and an upper bracket affixed to the cover having a downward extending vertical portion, the upper and lower hangers engaging the upper and lower brackets and the springs of the upper and lower hangers being resi

Abstract: In a dual stage power transistor type amplifier in which a video signal is applied to the base of a first stage transistor and in which the output of the first stage is direct coupled to the emitter of the second or power stage, and in which the second stage has a substantially constant d.c. voltage applied to its base, and a higher constant d.c. voltage applied to its collector through a load impedance. A voltage limiting device such as a Zener diode is shunted across at least a portion of the load impedance. With the fixed voltage on the base and a limited d.c. voltage on the collector, saturation and overload of the transistor is prevented.

Abstract: Apparatus for filtering high frequency noise pulses from alternating analog data of a frequency F, which includes means to convert the analog signal to a square wave bi-level signal, sampling the square wave signal at a clock frequency of at least 8F, loading the sampled signals into a digital shift register at the clock rate, reading out in parallel at least the last three samples, and passing said samples to a majority gate, which outputs a signal representing the majority polarity of the three signals read. The output of the majority gate is then applied to a latch in synchronism with the clock signal, which converts it back to a square wave signal representing the noise filtered version of the input signal.

Abstract: A frequency tracking, adjustable duty cycle ratio pulse generator that accepts an incoming stream of equally time spaced spike pulses, which go to a first input of an OR gate. The output of the OR gate is fed back to a comparator which has a reference voltage on one input terminal, and receives the feedback voltage from the output of the OR gate through a first switch and through a capacitor. There is a shunt circuit around the capacitor that includes a series resistor and a second switch. The output of the capacitor also connects to a second resistor, to ground. In operation, the first switch is closed when the output of the OR gate is high and when the first switch is closed, the second switch is open, and vice versa. The duty cycle ratio is dependent upon the rate of charge of the capacitor, which is controlled by the capacitance and the second resistor.

Abstract: The method of tuning a flyback transformer in a cathode ray tube control system, for minimum ringing, which comprises the steps of adjusting the lateral position of the center plane of the high voltage or secondary coil, with respect to the center plane of the low voltage or primary coil, placing an electric sensor in the vicinity of the high voltage coil to pick up a signal, which is a function of the current in the high voltage coil, and applying that signal to an oscilloscope, and noting the change in amplitude of the ringing component of the signal as a function of the lateral displacement between the two coils. By this means, the selected relative position of the two coils which provides a minimum amplitude of ringing is found and the coils are locked in that relative position to each other and to the magnetic core.

Abstract: Apparatus by means of which a plurality of coaxial cables can be connected through a flexible adapter board to a printed circuit mother board, comprising, a rigid metal chassis and means to support a flexible adapter board, by means of screws attaching it to the chassis. On one end of the adapter is a metal bracket having a flat portion parallel to and spaced from the adapter board, to which are fastened a plurality of coaxial cable terminals. The central conductors of each terminal extends as pins to and through selected holes in the adapter, and are soldered to the metal conductors on the surface of the PCB adapter. At the second end of the adapter is a male terminal, which is adapted, to be inserted into and connect with a printed circuit board receptacle, positioned on the mother board, which is conventionally fastened removably to the chassis.

Abstract: A dynamic slicing compensator for attenuated pulse width modulated signals, for use at the receiving end of a transmission line which comprises a voltage comparator the negative input of which is connected to the end of the transmission line. A negative peak riding circuit is provided with sufficient time delay to substantially follow the negative peaks of the pulse width modulation signals. A reference or slicing voltage is provided, preferably approximately midway between the negative peaks and the baseline. This reference voltage is connected to the positive input of the comparator. As the attenuation and distortion increases, the negative peaks become smaller and the reference voltage similarly becomes smaller, maintaining a substantially constant ratio to the value of the negative peaks.

Abstract: This invention relates to improvements in magnetic tape transport mechanisms and provides means for facilitating the visual inspection of the magnetic head for use in combination with a flux shield for the magnetic tape. Reflector means is disposed in such a manner that the magnetic head may be easily visually inspected when the flux shield is in a position removed from the vicinity of the magnetic tape.

Abstract: The present invention is an improved capstan which is used in a magnetic tape transport system, to accelerate a length of magnetic tape. The capstan includes a cylindrical post, adapted to be connected to a drive shaft of a capstan motor in a magnetic tape transport system, a pair of discs, each of which has a set of outer holes disposed adjacent to and distributed about its periphery and a set of inner holes disposed adjacent to and distributed about its central axis, coupled together by the cylindrical post disposed about their central axes. The capstan also includes a first set of cylindrical posts, coupling the inner holes of one disc to the inner holes of the other disc, and a second set of cylindrical posts, coupling some of the outer holes of one disc to some of the outer holes of the other disc. The capstan further includes a cylindrical tape band, which has a set of grooves running concentrically with the discs and the other edges of which are joined to the peripheries of the discs.

Abstract: In an oscillograph, a roll of recording paper is supported on a rotatable shaft such that the strip of recording paper passes over a metering roller driven at constant speed by a drive motor. Means to brake the shaft and prevent overrun of the recording strip comprises a magnetic solenoid-operated cone brake, adapted to momentarily place braking effort to the shaft. The cone brake has an appropriate friction liner, and serves to stop the roll, and prevent overrun. The braking effect is controlled by an electrical circuit that provides braking current to the solenoid for a selected short interval of time, sufficient to brake and stop the roll. At other times, there is no power applied to the brake.

Abstract: The invention is a tape path of a magnetic tape which is incorporated in a tape transport system. The tape path includes a file reel and a machine reel, each reel driven by a drive motor, a capstan, a magnetic head and a control system for controlling the two drive motors and the capstan. The tape path also includes a pair of vacuum chambers disposed in a V with the vertex of the V formed at their closed ends, a pair of auxiliary vacuum chambers disposed adjacent to each vacuum chamber, and a set of rollers and air bearings to guide the magnetic tape along the tape path.

Abstract: The end of a movable belt adjoins a supporting surface for removing a bottom sheet from a stack of sheets sitting on the supporting surface. A wall structure over the conveyor belt prevents those sheets other than the bottom sheet from being removed from the stack. The sheet supporting surface may be a transparent plate with a document reader located thereunder, thus allowing sheets containing information thereon to be placed face down on the glass plate and optically read automatically before removal by the movable belt.

Abstract: This abstract describes apparatus for improving the operation of magnetic tape decks which have two parallel wall vacuum columns and two tapered wall vacuum columns, in which means are provided to minimize the tape excursion in the tapered columns. Because of the small mass of the tape in the tapered colUmns, the tape can accelerate very rapidly, and when doing so may cause a reversal of air flow from the vacuum columns acting like an air pump, for example, when the tape is moving outwardly. In the tapered column, with wide excursiOns of the tape, there is danger of flutter and oscillation when the tape force varies in a pulsating manner and a resonance can be set up. A check valve is applied between the tapered vacuum column and the vacuum plenum, so that when there is an outward excursion of the tape the check valve will close and there will be an increasing vacuum in the column. This will provide a greater force restricting outward movement of the tape.

Abstract: The specification discloses a cathode ray lighthead for an electromechanical plotter. The head is adapted to be mounted upon the carriage of an X-Y Plotter in lieu of a conventional stylus. Plotting is effected on a photographic film through a combination of motions which include sweeping the beam in addition to mechanically moving the carriage. The system will produce both straight and curved lines of various widths, as well as symbols having any desired orientation.

Abstract: This invention covers means in connection with magnetic recording devices, to position, latch and remove reels from a driving hub, and actuation means therefor. The hub onto which the tape reel is placed carries an elastic sleeve about which the reel is placed. An actuation rod which passes through the hollow shaft of the drive motor carries a spool, to which three link bars are hinged. These are in radial planes spaced at 120.degree. to each other. The link bars are attached respectively to three shoes which are adapted to press outward against the inside wall of the elastic sleeve, which expanded outward against, and securely grips the reel hub. Also involved in the linkages between the link bars and the shoes are three dogs, which are adapted to press the reel hub against the drive hub and/or to lift the reel hub, depending on the position of the actuator rod.

Abstract: This abstract describes an improvement in conventional vacuum column magnetic tape decks whereby the tape can be threaded directly across from one reel to the other after which it will automatically be threaded into the vacuum chambers, in sequential order. The first reel unwinds to load the first vacuum column and then the second reel unwinds to load the second column. The tape is held stationary over the capstan during the interval between the first entry of the tape into the first vacuum column until the tape has progressed within that column to a selected point after which time the tape is released. Before the tape is released there will be sufficient time available for the tape loop from the second reel to unwind and be locked into the second vacuum column.