Abstract: In a parallel resonant circuit having an inductor connected in parallel with a capacitor, a sensing resistor is connected in series with the inductor to sense the current in the resonant circuit. The voltage drop across the sensing resistor is applied to an operational amplifier and the amplified output voltage is fed back to the circuit loop out of phase with the sensed voltage drop so as to reduce the effective circuit resistance and thereby increase the circuit Q.

Abstract: An oscillation system includes a pair of differentially connected oscillator transistors having a resonant tank circuit connected between collector electrodes and a current source transistor connecting both emitter electrodes to ground. The collectors and base electrodes of the oscillator transistors are cross connected to provide regenerative feedback and matched resistors connect each collector to a source of operating potential. A shunt transistor is connected to the collector of one of the oscillator transistors and a series transistor connected to their common emitters. The currents of the shunt and series transistors are combined in a second current source transistor. Control signals applied to the base of the series transistor vary the oscillator current (and thereby its frequency), and produce opposite current changes in the shunt transistor, thus maintaining the DC component of the oscillator output signal at a constant.

Abstract: An arrangement for simultaneously producing signals having a decreasing frequency and signals having an increasing frequency. In this arrangement the signals have frequencies which are complementary relative to the double value of a central frequency. The arrangement includes a pair of voltage-controlled oscillators controlled by signals supplied by a control generator. The arrangement is characterized in that for each oscillator there is provided with a phase control loop and that the control generator is of the digital type designed to supply two pairs of digital signals. One pair is applied to the frequency dividers and the other is applied to the oscillators so as to tune them to such a frequency that they are in the operating range of the phase control loop.Use: Radio-electric transmission of data.

Abstract: Disclosed is a circuit for locking a harmonic-rich oscillator, such as the crystal-controlled type, to provide as its output, a signal at a designated frequency characterized by minimum harmonic content and high stability. The circuit includes a combination of gates in the oscillatory feedback path controlled by single-shot multivibrators with time constants such that any tendency of the period of the output signal to compress or expand is overridden by the respective expansion or compression thereof by the appropriate single-shots.

Abstract: A bucket brigade device (BBD) circuit is used to delay the output of the limiter in an FM receiver for use in a coincidence-type FM demodulator to which the undelayed limiter output is also supplied. The BBD circuit is stepped forward by a fixed frequency oscillator of a frequency conversion stage additional to the tunable converter of the receiver and the amount of delay is determined by a frequency division operation as well as the BBD length. The fixed frequency oscillator can be used also for automatic fine tuning and an arrangement for disabling the BBD stepping provides a good form of muting or blanking. The circuits are integrable in monolithic form.

Abstract: An amplitude modulated transmitter is disclosed for use in the frequency range generally below 50 mega-hertz. The transmitter is provided with a series diode modulator which is provided with a corrected modulating signal which biases the diode in proportion to the modulating signal. The modulating signal is derived from comparison in a difference amplifier between the desired audio input signal and a signal derived from the output of the output amplifier by means of a directional coupler. The directional coupler samples the magnitude and phase of the current and voltage at the output and feeds a signal proportional to the inciden as contrasted to any reflected component, of the output signal.

Abstract: To demodulate an incoming oscillation consisting of a succession of distinct signal frequencies, particularly in a data-transmission system using an alternation of two keying frequencies, the incoming oscillation is squared and then passed through a differentiator deriving a pair of closely spaced trigger pulses from any zero crossing of the incoming oscillation. The first trigger pulse causes the transfer of the contents of a buffer register, receiving the reading of a pulse counter, into a digital/analog converter whose output is compared with a reference voltage in a threshold circuit; the second trigger pulse resets the counter which receives locally generated clock pulses whose cadence is high compared to the signal frequencies.

Abstract: A one-piece sheet metal base for a tubular lamp having pinch-sealed ends is adapted to be simply pushed onto the lamp end by hand. It comprises a flat portion having longitudinally extending side wall portions exceeding slightly in height the thickness of the pinch seal with inwardly turned underbeveled extensions which resiliently grip the pinch seal for frictional retention. A distal end wall portion has a forwardly turned lip adapted to overlie a pigtail attached to the inlead. Mitered corners on the underbeveled extensions and on the end wall provide a passage for threading the pigtail through the base.

Abstract: A pulse amplitude modulator which has particular utility in analog-to-digl and digital-to-analog converters of the continuous variable slope delta (CVSD) modulation type. A CVSD analog-to-digital modulator first compares an incoming analog signal with a synthesized signal. The error signal is periodically sampled, with the output of the sampler being a clocked binary signal having the same polarity as the error signal. This binary signal, which is the output signal for the CVSD modulator, is simultaneously tested for patterns of similar bits and utilized to correct the amplitude of the synthesized signal in the pulse amplitude modulator. The pulse amplitude modulator utilizes C-MOS transmission gates and filter circuitry to synthesize a digital signal which, when integrated, approximates the analog input signal.

Abstract: An oscillating apparatus allowing for synchronization to an external sinusoidal source, and in which a unidirectional element is so located that the oscillating device may be replaced without the necessity of altering circuit elements to maintained synchronization and the desired nominal frequency of operation.

Abstract: Spark plugs having electrodes formed from combinations in defined proportions of tungsten, vanadium, depleted uranium, rhodium, iridium, palladium, nickel, chromium, copper, barium aluminate, iron, and thoria. Various advantageous electrode configurations are described, as well as methods of constructing the spark plugs.

Abstract: A gas discharge tube for efficiently generating ultraviolet radiation, which is transmitted through a portion of the tube envelope for spectrographic use. The tube is filled with hydrogen or deuterium at a low pressure. The tube envelope is formed of a glass envelope which has a cylindrical envelope portion about the anode and cathode discharge path which is circumferentially thinned to from about 0.005 inch to 0.020 inch.

Abstract: A pulse width modulated signal amplifier including a signal input circuit, a clock pulse generating circuit, a pulse phase modulating circuit and a pair of pulse transformers. The pulse phase modulating circuit is supplied with the output signal of the signal input circuit and the clock pulse signal in such a manner as to produce a pair of pulse signals having a phase difference which is proportional to the output signal level of the signal input circuit. Each primary coil of the transformer is supplied with a pair of pulse signals, and the secondary coils are connected so as to add and subtract the pulse signals respectively. A rectifying circuit is supplied with the output signals from the secondary coils so as to produce the finally constituted pulse width modulated signals where the width of the pulse is proportional to the output signal level of the signal input circuit. At the same instance it is applied to a load through a low pass filter.

Abstract: An instrument for measuring and testing wet cell storage battery charge levels including the total charge level and the charge level of individual cells. The instrument has an autopolarity feature and utilizes a diode rectifier circuit with a DC voltmeter connected across the terminals. Separate circuits may be selected to provide two voltage readout scales including a scale for measuring the total charge level and a scale for measuring the charge of individual cells. The device has unique conductive probes at the ends of the test leads, the probes being adapted for immersion in the electrolyte of the cells in order to measure the charge level of individual cells. The probes are also used to provide electrical contact across the battery terminals for the total charge test. The probes are elongated steel rods coated with cadmium plating and having the outer ends ground off so that a roughened steel end surface is exposed to the electrolyte.

Abstract: An oscillator circuit is provided which employs a single active element. In particular, the circuit utilizes a novel four-terminal semiconductor device which is able to act as a transistor with three of its terminals and, in case of use as the transistor, has the emitter-grounded current amplification factor h.sub.FE controllable with a voltage at its fourth terminal. When the novel four-terminal semiconductor device is connected so as to operate as an emitter-grounded transistor, voltage changes at its output terminal, which corresponds to the collector of the transistor, is the same in phase as voltage changes at its fourth terminal. This fact is utilized in the present invention to cause oscillation by the generative feedback from the output terminal to the fourth terminal.

Abstract: A circuit for the repetitively pulsed operation of a xenon arc discharge lamp. A first SCR is responsive to a first control circuit when fired to allow the charging of a capacitor through a first inductor from a DC energy source. A second SCR is responsive to a second control circuit, and when fired connects the capacitor through a second inductor to a lamp to provide an operating current pulse for the lamp. Also, upon firing of the second SCR, the capacitor supplies a voltage pulse to a pulse transformer which in turn generates a high voltage pulse for ionizing the lamp. The first SCR is responsive to its control circuit to be conductive only when the capacitor is discharged and the second SCR is responsive to its respective control circuit to be conductive only when the capacitor is fully charged. In actual operation, one SCR must have been non-conducting for a predetermined time before the other SCR is allowed to become conductive thereby to prevent shoot-through.

Abstract: In a display device having a plurality of signal lamps, each lamp is coupled to a signal contact through a first decoupling diode and a test voltage having a voltage lower than that of the signal voltage is coupled to each lamp by means of a series resistance and second diode to generate a current acting both to pre-heat the lamp and for use in indicating lamp failure with a further diode coupled to the second diode providing an input to testing means giving an indication of a lamp failure.

Abstract: The invention utilizes a four-port hybrid junction in which a signal to be amplified or a low level stable reference signal is coupled to a first port in which a pair of similar or matched amplifiers or oscillators are coupled to the respective second and third ports of the hybrid, and in which the resulting amplified or coherent stabilized power of the two amplifiers or oscillators is provided at the fourth port of the hybrid junction.

Abstract: A demodulation system for digital information, recorded by an FM or PM system, which provides a clock output pulse whose pulse width is proportional to the time length of the preceding bit frame and said clock output signal is utilized for demodulating the recorded data. Said pulse width can be controlled either by an analog or a digital circuit and thus, the present invention has the advantage that the information is demodulated stably though the moving speed of the recording medium is changed or deviated.

Abstract: A reference carrier signal is combined with a phase modulated signal of the same basic frequency to generate an output signal the amplitude of which varies in accordance with the phase difference between the phase modulated signal and the reference carrier. The permissible modulation angle is increased by vectorally adding the phase modulated signal with a reference signal having a phase different from the comparison reference carrier. The vector sum signal is amplitude-limited so that the signal produced by the comparison will only be responsive to phase angle and not amplitude.