Abstract: The invention relates to apparatus for the testing of high circuit density devices fabricated by large scale integration techniques. More specifically, the invention is directed to a test fixture used in a test system for determining the merit or electrical integrity of small semiconductor chips, diced from a semiconductor wafer having a large number of chips. Each chip being a high circuit density device, e.g., a small monolithic semiconductor structure having a large number of closely spaced circuits thereon and therein.

Abstract: A conductivity monitoring system including a temperature sensing means for sensing the temperature of a fluid and also providing a temperature compensated conductivity signal. Electronic circuitry is provided for detecting and indicating the inoperability of the temperature sensor.

Abstract: An a-c plasma display panel including apparatus for driving the keep-alive cell sustain signal circuits in a non-fixed relation with address pulses. By constraining the keep-alive cells to be sustained in a time relation dependent on the address of a cell being addressed it is possible to increase the margins for the address signals and, in general, permit a reduction in magnitude of such address signals.

Abstract: A self-tuning filter is provided through the employment of a voltage tunable filter circuit which simulates a series resistor-inductor-capacitor (RLC) circuit and which is tunable to vary or adjust its resonant frequency in response to the value of an input control voltage. The filter is made self-tuning through the provision of suitable circuitry, responsive to simulated inductance and capacitance voltages, to generate the input control voltage and hence render the voltage tunable filter circuit resonant at the frequency of an applied input signal.

Abstract: A light source device having an elongated baffle plate positioned between a light source and a cooling means for regulating a cooling flow from said cooling means. Said baffle plate has a slit and bent portions extending for covering said light source so that the bulb wall of the light source is evenly cooled.

Abstract: Operation of the release contact causes a capacitor in the light measuring circuit to be connected to the D.C. supply. The voltage across the capacitor is applied to the gate of a thyristor in the ignition circuit. Only when the voltage across the capacitor has reached a value for proper operation of the exposure control circuit which terminates the flash, is sufficient voltage applied to the gate of the thyristor in the ignition circuit to cause it to fire, thereby causing the flashtube to ignite.

Abstract: An improvement of the Wunsch test method for measuring pulsed-power failure thresholds of bipolar transistors and p-n junction diodes using short-pulse testing with pulse durations of 100 nanoseconds or less. A square pulse of reverse current is used to damage the p-n junction of interest, and the absorbed power is computed from oscilloscope traces of voltage and current. A constant-current pulse is used rather than the constant power pulse of the Wunsch test method, thereby limiting the damage done to the device and permitting a wide range of device parameter to be observed. The degree of device degradation is utilized to distinguish between true and false measurements of thresholddamage input-power and also to ensure that the individual failure levels of specimens of a sample actually are threshold failure levels rather than overkill levels, in order that the average of these levels represents, approximately, a 50% probability of failure for the sample.

Abstract: Method and apparatus for analyzing the harmonic distortion present in an input signal wherein first and second reference signals are generated differing by a small offset frequency. The first reference signal is mixed with the input signal to provide an intermediate carrier signal which is modulated with the second reference signal to provide a measurement carrier signal which in turn is modulated with the input signal to produce an output signal which is filtered to isolate a specific signal. By isolating a specific signal for each harmonic of the input signal to be analyzed, the proportion of each such harmonic is revealed as a percentage of the fundamental harmonic of the input signal.By adding a tunable oscillator to the apparatus, it may function as a wave analyzer, in which case the specific output signal represents the magnitude of any selected component of the signal to be analyzed.

Abstract: A multi-range electrical measuring or indicating instrument including a current sensitive movement adapted to provide an indication of an electrical signal. The movement is connected to contacts which make electrical connection with contact members on a printed circuit member. The printed circuit member includes circuit apparatus for controlling the sensitivity of the instrument, and is movable relative to the contacts to selectively connect the circuit apparatus to the movement.

Abstract: A low frequency electro-thermal filter includes a pair of thermally coupled transistorized differential amplifiers. One of the differential amplifiers comprises a pair of heater transistors and the other differential amplifier includes a pair of sensor transistors, each heater transistor and its associated sensor transistor being fabricated on a single semiconductor chip. The heater transistors in the first differential amplifier serve differentially to heat the sensor transistors in the second differential amplifier in response to an input signal. The differential heating of the second differential amplifier differentially affects the electrical parameters of the sensor transistors and tends to upset the current balance between the stages of the second differential amplifier. A feedback loop is provided around the second differential amplifier for reestablishing the current balance thereof.

Abstract: An improved testing circuit is provided which includes a pair of comparator circuits each of which is disposed for comparing two minimum threshold amplitudes of responses from a device under test, and a multiplexer circuit coupled to the outputs of the pair of comparator circuits for switching between the outputs of the pair of comparator circuits. The use of a pair of comparator circuits and a multiplexer circuit allows continuous operation of the comparators thereby providing accurate testing at high speeds of operation.The improved testing circuit of this invention also includes a skew adjustment circuit which provides for adjustment of the leading and trailing edges of a test stimuli signal from one testing circuit with respect to the leading and trailing edges of test stimuli signals from other testing circuits incorporated in a circuit testing system.

Abstract: An automatic flash device comprising:A power source,A main capacitor to be charged to a certain level by said power source,A discharge circuit being connected to said main capacitor,A control circuit to make the amount of electricity discharged by said discharge circuit correspond to flash photographing information,A means to start discharging, which is actuated after a shutter release means of a camera is actuated to start the discharging of said main capacitor, andA means to cause a flash tube to emit light when the amount of electricity charged at the main capacitor reaches such a value as corresponds to flash photographing information.

Abstract: An anti-skid brake control system having two wheel velocity pick-up coils connected to respective common mode rejection circuits. A coil open detector including a Norton amplifier is also connected from the said circuits to disable the system controller should an open develop in one of the pick-up coils.

Abstract: A sense amplifier having three transistor stages. A balanced differential input stage with high noise immunity to capacitively coupled noise. A second threshold stage is provided with protection against an output being caused by a permanent potential on the input, false trigger protection circuitry, and protection against supply voltage and other minor variations. A differential output stage increases noise immunity of the amplifier output and protects against a short circuit in the output.

Abstract: Accelerator apparatus having an eccentric-shaped, iris-loaded deflecting cavity for an rf separator for a high energy high momentum, charged particle accelerator beam. In one embodiment, the deflector is superconducting, and the apparatus of this invention provides simplified machining and electron beam welding techniques. Model tests have shown that the electrical characteristics provide the desired mode splitting without adverse effects.

Abstract: A method of obtaining a distribution profile of electrically active ions, of one type conductivity, implanted into a semiconductor, of an opposite type conductivity, is carried out with the aid of an integral target of the semiconductor. The integral target is formed with a plurality of doped regions of different background impurity concentrations, respectively, therein. Each of the operations of annealing, angle-lapping, and staining the doped regions to determine P-N junction depths therein is carried out on all of the doped regions simultaneously. An enlarged photograph of the stained angle-lapped portions of the doped regions provides directly a histogram of the distribution profile.

Abstract: There is disclosed an electrical system and method for supplying operating potentials to gaseous discharge display panels and improving the performance characteristics of such devices. Write and erase operations are accomplished by means of controlling the level of pedestals which has the advantage over previous system in the improvement of sustaining and write/erase characteristics of gaseous discharge display/memory panels of the type disclosed in Baker et al. U.S. Pat. No. 3,499,167, which in turn produces a larger 100 percent operating window.

Abstract: A starterless circuit arrangement for the ignition and the operation of one or a number of series connected, low voltage fluorescent lamps which are connected with a stray field transformer coupled with a voltage source. The stray field transformer produces the no-load voltage needed for firing the lamps and possesses heating coils which are connected with the electrodes of the lamps. A cold conductor having markedly positive resistance characteristic is connected in parallel with at least part of the secondary winding of the stray field transformer in order to maintain the voltage applied to the lamp(s) at a value beneath the firing or ignition voltage for such length of time until the electrodes of the lamps are pre-heated.

Abstract: An arrangement is described for testing diodes serially interposed in parallel feed lines between the terminals of a voltage source and corresponding d.c. bus bars. The arrangement provides for in-circuit check out of the diodes by providing a first switching means positioned in the feed line between one side of the diode to be tested and its corresponding voltage source terminal. A second switching means is connected to the other terminal of the voltage source, through an ammeter, to the side of the diode to be tested which is nearest the voltage source. The first switching means is opened and then the second switching means is closed which impresses across the diode a reverse voltage substantially equal to the terminal voltage of the voltage source. The ammeter provides a reading of the cut-off current flowing through the diode. A parallel arrangement including a voltmeter and resistor are provided for doing a reverse voltage check on the diode and a calibration check on the ammeter as required.

Abstract: A planar transmission line comprising a Gunn effect semiconductor having an epitaxial portion as the propagating medium amplifies and switches r.f. signals and is not transit time limited in the direction of propagation. The spacing between the transmission line conductors and the dopant concentration of the Gunn effect semiconductor are selected to prevent the formation of domains and thereby prevent Gunn oscillations from occurring at E fields above the Gunn threshold.