Abstract: A signal isolating and sampling circuit using a transformer to isolate a signal input circuit from a signal output circuit. Signal sampling switches are used in the input and output circuits to sample an input signal applied to the input circuit. A photocoupler is provided for coupling a switch selecting signal to the sampling switch in the input circuit while an energizing signal for driving the sampling switch in the input circuit is supplied through the transformer from an energizing signal source connected to the signal output circuit. The energizing signal is rectified in the signal input circuit and used to drive the signal input circuit sampling switch under control of the switch selecting signal.

Abstract: A battery backup system for an AC energized DC supply has an AC line monitor for producing a pulse signal having a pulse width dependent on rise time of the AC signal and a frequency dependent on zero line crossings of the AC signal. The pulse signals are checked for frequency and pulse width by being used to control the charging time of a timing capacitor for a timer and to be compared with the pulse width of a predetermined reference pulse, respectively. The occurrence of a defect in the pulse signals stemming from either pulse testing criteria is effective to trigger an SCR circuit into conduction to connect a backup battery to the load devices to replace the DC power formerly being supplied by the AC line. After restoration of the AC power, the backup battery is removed following a fixed time delay to allow the AC powered DC supply to stabilize.

Abstract: A bridge circuit having reference and measurement thermistors in respective adjacent arms is automatically readjusted to off-set any long term drift of the thermistors. The readjustment of the bridge circuit is performed between normal measurement operations using a bridge output error signal produced by the drift of the thermistors. The output signal of the bridge circuit is also applied to a comparator circuit to produce a polarity characterized output signal in response to the relative magnitude between the bridge output signal and a fixed reference signal. This characterized output signal is used to control the counting direction of an up/down counter. A source of fixed frequency pulses is connected to the input of the up/down counter during a sample window time between the measurement operations to change the count stored in the counter in accordance with the direction of counting as determined by the output signal from the comparator.

Abstract: A recording apparatus includes a plurality of Xenon flash tubes and a separate enclosure for each of said flash tubes. Each enclosure is provided with a slit through which light from the associated flash tube emerges to form a relatively small line segment. The slits are all located in a recording plane and may be disposed in an H-shaped or C-shaped recording array, as desired. When placed in cooperative relation with a moving light sensitive recording medium that is ultrasensitive to a predominant wavelength of the light produced by said flash tubes, selective and appropriate flashing of said flash tubes produces dense analog time code and other traces on said recording medium.

Abstract: The generator includes an input terminal, an output terminal, and three channels connected between the input and output terminals. The first channel contains a first amplifier and a first FET switch connected in series between the terminals. The second channel contains a second amplifier and a second FET switch connected in series between the terminals. The third channel contains an adjustable resistor and a third FET switch connected in series between the terminals. An adjustable bias signal positively offsets the output signal of the first amplifier and negatively offsets the output signal of the second amplifier to produce a signal deadband. When an applied input signal lies within the deadband, a signal from the resistor lies between the amplifier output signals, and a pair of comparators turn on the third FET and turn off the first and second FET's. This produces an output signal which follows the input signal with a gain determined by the resistor adjustment.

Abstract: A recording head for electrographic recording has a plurality of electrically conducting flat plate electrodes arranged in a side-by-side electrically insulated relationship on an electrically insulating common support bar. A recording end of each electrode has a recording pin which is offset with respect to a center line of the electrode while a terminal end of each electrode has an electrical connection terminal. An air plenum is formed between the support bar and the electrodes by an adjacent cavity in each of the electrodes to allow a supply of air to be supplied to each of the electrodes. An air passage is formed by a depression in a surface of each of the electrodes extending between the air plenum and an exterior surface adjacent to the recording pin. A pair of end plates are arranged to provide an air-tight seal with the ends of the stacked electrodes and to provide hose connection means for admitting air from an air source into the air plenum.

Abstract: A fuel injected engine timing instrument measures timing advance of fuel injection onset as referenced to a predetermined cylinder top-dead-center to provide an analog output signal proportional to fuel injection advance for the engine. This output signal is obtained by measuring the time required for an engine flywheel to move a predetermined distance which movement is sensed by a transducer responsive to timing indicia on the flywheel. An output signal from the transducer is applied to a gating circuit in combination with a signal derived from a transducer detecting the onset of fuel injection into the reference cylinder of the engine. The gating circuit is enabled by these two signals to control the duration of application of output signals from a fixed frequency oscillator to a counter. The output signal from the transducer sensing the movement of a flywheel is also used to control a second gating circuit arranged to apply the output signals from the oscillator to a second counter.

Abstract: A voltage-frequency converter having an integrator of which the inverted input terminal is supplied a voltage to be converted while its non-inverted input terminal is supplied said voltage through a first switch means and a voltage comparator of which the inverted input terminal is supplied an output voltage of said integrator while its non-inverted input terminal is continuously supplied with a constant voltage and selectively supplied with said voltage to be converted through a second switch means, wherein an output of said voltage comparator is made to control said first and second switch means, whereby said voltage to be converted is converted into a signal having a frequency proportional to said voltage to be converted.

Abstract: A vector CRT display apparatus for faithfully reproducing an analog signal having high frequency components include an A-D converter, a digital minimum/maximum circuit and a recirculating shift register to derive from the signal, in successive sampling periods, two digital words representing, respectively, a minimum amplitude value date point and a maximum amplitude value data point of the signal. In each sampling period, the minimum/maximum circuit stores in the memory the most relevant of the minimum and maximum amplitude values and determine whether the remaining values should be held over to the next sampling period before it is stored, or can be discarded. As a result, if new minimum and new maximum amplitude values occur in the same sample period, one will be loaded into the memory and the other will be held over and loaded into the memory in the next sample period.

Abstract: A display apparatus includes a computational circuit that is connected to the output of a memory to introduce between a stored digital representation of successive sampled data points, by an interpolation method, additional virtual or interpolated data points. The interpolated data points are computed in accordance with the magnitudes of the separations or differences in value between the sampled data points. In a CRT display or hard copy recorder, this allows a higher cathode ray sweep speed, and hence, a higher density of raster lines, and consequently, an improvement in resolution, smoothness and continuity of the display, for a given size memory.

Abstract: A solid state pH measuring electrode having the pH measuring electrode structure formed by successive layers on an insulating substrate with an outer pH sensitive glass layer being deposited on a supporting solid electrolyte layer by RF sputtering. The reference electrode is similarly formed by depositing an outer layer of glass onto a supporting solid electrolyte layer by RF sputtering with the temperature expansion of the glass and supporting solid electrolyte structure being selected to produce a differential expansion causing random cracking of the glass layer during temperature cycling of the reference electrode. A combination structure is provided wherein the pH measuring electrode and the reference electrode are formed on opposite sides of the same electrically insulating substrate with a thermal compensating element being included in the integrated package.

Abstract: An improved X-Y or vector type cathode ray tube circuit includes means to sense the imminence of and to inhibit excessive concentrations of electron beam current during the plotting of X-Y loops, which concentrations produce spots or points on the cathode ray tube screen that are essentially repetitive and convey no useful information to the observer, and if allowed to persist, tend to burn the phosphor coating of said screen.

Abstract: An improved control system for energizing a stepping motor varies the width of the stepping pulse to the stepping motor as the motor transfers from one balanced state to another in order to provide additional starting torque and disconnects the energizing source from the motor when the motor is in its balanced state in order to conserve energy.

Abstract: An analog isolator includes a circuit wherein a power transformer has a primary winding for connection to an A.C. source, a first and second power take-off secondary windings and a first and second signal secondary windings. The A.C. signal of the first signal secondary winding is compared with an input signal to provide cross-over pulses. Those pulses are applied to control an isolator device such as a photocoupler. The output signal from the photocoupler is applied as gate control signals to control the selective gating of the signals from the second signal secondary winding. The selectively gated signals are applied either to a sample-and-hold arrangement or to an integrating smoothing circuit to provide effectively a reconstruction of the input signal but conductively isolated from the input circuit.

Abstract: A slack tape loader for a tape transport apparatus has a signal generator selectively energized by a tape loading control switch to produce an enabling signal for a reel motor control servo circuit. The enabling signal has a duration which will energize the reel motor control servo for a short period of time to load the slack tape on tape storage reels. Concurrently, the tape transport is operative to detect a tensioned state of the tape. The enabling signal is recurrently produced by the signal generator in response to the tape loading control switch until the desired tape tension is detected by a tape tension sensing means to produce an output signal for disabling the signal generator.

Abstract: A servo-motor control system varies a set point input signal to a comparator between predetermined limits in order to establish three detectable output conditions. When the difference between the feedback signal and the set point signal exceeds the average deviation of the set point input to the comparator, the comparator produces a characteristic output signaling rotation in one direction. When this difference signal is less than a negative quantity equal to the average deviation, the comparator produces a characteristic output which signals rotation in the other direction. If the difference signal is less than the absolute average value, then a third characteristic output is produced which causes a cutoff in the energization of the motor.

Abstract: A noise abating plug for a fluid control valve includes a perforated sleeve that forms one end portion of the plug and a plurality of spaced apart perforated discs that extend between a hub portion of the plug and the inner wall of the sleeve portion. The perforations in the sleeve and in the multi-perforated discs form a varying number of restrictive passageways for the fluid under control as the plug is moved between its open and closed positions and thereby maintain the pressure reduction occurring at the perforated sleeve and perforated discs at values which minimize the noise created by the fluid as it flows through the valve.

Abstract: An optical gauging apparatus includes structure defining a pair of light beams. One of the beams comprises a reference beam while the other is a measuring beam. An object to be gauged is positioned to partially interrupt the measuring beam. The partially interrupted measuring beam is compared with the reference beam as the object to be gauged is run through the gauging process.

Abstract: A selective addressing means for a plurality of signal modules includes a plurality of electrically identical component units each arranged to contain a plurality of the modules. Each component unit includes apparatus for internally establishing a self-address code at the input side of each of the component units. Also included in each of the component units is a structure which effectively modifies the address code found at the input side thereof and applies the modified code to the output side thereof. An interconnection is provided for applying the modified code from the output of the preceding component unit to constitute an overriding address code to the input of the next succeeding component unit. Logic circuitry is provided to correlate the thus established series of address codes with corresponding address signals from a central processor to access the selected module.

Abstract: A two-wire voltage to current converter and transmitter for extremely high output impedance transducers has an input which floats with respect to the power supply ground potential and is referenced to the power supply ground potential by means of a level shifting comparator.