Abstract: A tachometer for measuring and comparing the angular velocity of a first and a second wheel of a vehicle includes means for sensing and generating a train of pulses for each of the wheels wherein the repetition rates of the pulse train varies in proportion to the angular velocity of the wheel. For each of the wheels a frequency doubler is provided for doubling the repetition rate of the pulse train of the varying repetition rates having pulses of the same pulse width and amplitude. For each wheel the frequency doubled pulse train is then integrated to provide a DC output. The two DC outputs for the two wheels are then compared, selected and applied to corresponding output terminals of the tachometer.

Abstract: In combination with an asynchronous detector for detecting a particular digital word within a train of signals wherein the detector samples each bit in the train a plurality of times and provides a comparison signal in response to a predetermined number of correlations between the samples and a stored word, an analog to digital converter including signal conditioning means having first and second modes of operations for converting a received analog signal to a digital signal in both modes of operation and inserting periodic error pulses in the digital signal in the first mode of operation and switch means coupled to the signal conditioning means and the detector for switching the signal conditioning means between the first and second modes of operation in response to a comparison signal from the detector.

Abstract: A modulating and demodulating system for converting a plurality of baseband space division signals to a frequency division multiplexed signal. The baseband signals are sequentially sampled and converted in an analog-to-digital converter to a series of digital words. Predetermined mathematical algorithms incorporating digital filters, multipliers and shift registers are used to convert the series of digital words to a frequency division multiplexed digital signal. Aliasing of the baseband signals provides the required dispersion through a predetermined frequency range. A digital to analog converter coupled to a conventional balanced mixer and oscillator is then used to up convert the resulting signal to the desired frequency range. A high pass filter is used to remove the image frequencies. The resulting frequency division multiplexed signal may be transmitted by conventional means to a remote location where demodulation is accomplished essentially by reversal of the modulation process.

Abstract: A split collector lateral transistor wherein the amount of the emitter encircled by each of the collectors is unequal so that a greater current flows in one of the collectors and the base current plus the current flowing in the other collector is approximately equal to the greater current flowing in the one collector.

Abstract: In a method of an apparatus for forming a conductive layer on a substrate wafer by evaporative, sputtering or other similar processes performed under a controlled environment, there are provided means for holding the wafer at the edge portions thereof with minimal holding contact, means orbiting rotating the wafer about a first axis which forms an acute angle relative to the major surfaces of the wafer while the processes for forming the layer is in progress so that the layer is formed uniformly, and means orbiting the wafer about a second axis which is substantially orthogonal to said first axis.

Abstract: An audio compressor amplifier including an operational amplifier with compressor means connected from the output to the input for compressing signals at the output to a predetermined constant level in a predetermined attack time and including a plurality of diodes connected to reduce the series resistance in the compressor means for decreasing the attack time when the output signal exceeds the predetermined constant level by a predetermined amount, and a gain control feedback resistor connected from the output to the input of the operational amplifier and including a second resistor and a plurality of diodes connected in parallel therewith to reduce the gain of the operational amplifier and provide peak limiting action when a signal at the output exceeds a predetermined value in excess of the predetermined constant level.

Abstract: An FM radio receiver with a discriminator having the output connected to a first bandpass filter, tuned to a frequency above the audio but within the bandpass of the discriminator, and to a second bandpass filter tuned to a frequency above the audio, within the bandpass of the discriminator and adjacent the bandpass of the first filter. The outputs of the two bandpass filters are connected to a selector circuit for selecting, as an indication of the strength of signals being received by the radio receiver, the output having the lowest amplitude signal thereon.

Abstract: A mode selector device, such as might be used in a projectile, allowing a simple manual adjustment before firing time to enable a function upon firing. A safe, small, reliable, "fail-useful" mechanism using shock to activate a cutter which removes a particular short in the circuit for each of a plurality of functions.

Abstract: Two signals received by spaced antennas or equivalent diversity receiving systems and having identical data signals, phase modulated on frequency-identical suppressed carrier signals, are combined to produce a more nearly error-free data output. Each input signal, after heterodyning, is multiplied by a distinct feedback signal to produce a phase-coherent carrier and a recovered data signal. Each carrier is filtered by a narrow bandpass filter and connected to a separate adder. The two multiplier outputs are also added together, then filtered in a low pass filter to provide a combined recovered data signal. This combined data signal is added separately to each coherent-phase carrier to provide the two distinct feedback signals for the input multipliers. When each carrier is phase modulated in quadrature with the same two data signals, the signals are phase shifted, after heterodyning, to separate the quadrature components.

Abstract: Digital data, differentially phase shift keyed on a suppressed carrier, double side band transmission, is recovered by multiplying the input signal by a signal derived from regenerative feedback and consisting of the sum of a phase-coherent carrier and the recovered data signal. The phase-coherent carrier is derived by alternate phase reversals of the incoming carrier, produced by the polarity changes in the data. The phase-coherent carrier and the recovered data signal are components of the multiplier output and are separated by bandpass and low pass filters respectively, the output terminal of the low pass filter also being the data output terminal. When a carrier has been phase modulated with two distinct signals in quadrature, the received carrier is phase shifted to produce two signals in quadrature, then each of the resultant modulated carriers is demodulated as with the single signal carrier, using one common bandpass filter.

Abstract: A remotely situated detonator is acoustically triggered to detonate explosives. Conduit means capable of propagating an acoustic wave is used to transmit a precoded acoustic wave signal from a transmitter to a receiver. The receiver is provided with means for converting the precoded acoustic wave signal to an electrical output signal to actuate the detonator and decoding means for discriminating against noise signals. For safety reasons, time delay means may be provided to delay generation of the acoustic wave signals until after a predetermined time period. The aforedescribed detonation system may be utilized to rejuvenate or activate subterranean petroleum, gas, geothermal steam, or water and the like.

Abstract: A system for differentiating between targets containing non-linear metal element junctions and their surrounding non-metallic environment. A spread spectrum illuminating transmitter is used in conjunction with correlation circuits in a receiver to enhance its signal to interference ratio and reduce required peak power level in the illuminator/transmitter.

Abstract: A time delay mechanism for projectiles utilizing angular acceleration to control the flow of a granular material. The angle of the path of the flow with respect to the radius vector is used to differentiate between constant angular velocity and angular acceleration. There are at least three modes in which this capability can be utilized in a projectile: (1) inert material may be moved from an initial location to provide "unlatching" action, (2) active or high energy material may be moved from one location to a second location for utilization at the second location, or (3) inert material may be moved from a location such as a firing chamber where it provides "safing" action and, simultaneously, active material may be moved into the chamber.

Abstract: A digital system for measuring a phase relationship between two noisy signals of a given period wherein the phase difference measurement may lie in the range of from 0 to 360 degrees. The noisy signals are amplified and limited so that the processed signal only contains noise in the time vicinity around the zero crossing points. Time interval counters are utilized to measure the time delay between signals and the time period of the reference signal. Phase relationship may be determined by multiplying the ratio of the two digital numbers produced by 360.degree.. Errors in digital outputs are minimized by digitally integrating the counter input during the noisy zero crossover periods. The measurements are completed within two period times of the signals being measured and may be repeated in each of the succeeding two period times.

Abstract: Apparatus and system for controlling the gate threshold settings of MNOS memory devices is disclosed. Positive or negative pulses depending on turn-on or turn-off of relatively large amplitude and relatively low frequency are applied to the gate of the MNOS device whose threshold is to be set and to whose gate a bias value equal to the desired setting has been applied. A feed back circuit, in response to the change in current conduction condition of the test MNOS device caused by the application of the pulses, reduces the magnitude of the pulses to a low value as the gate threshold value reaches the desired set value.

Abstract: A matched transmission line coupling an RF generator to an antenna and receiving Doppler altered reflected signals from the antenna. A pair of diodes coupled to the transmission line 90 electrical degrees apart at the RF frequency and oppositely poled so that the RF signal from the generator and the reflected signal from the antenna are heterodyned in each diode to produce a heterodyne signal which is in phase. The heterodyne signals are band limited, filtered and passed through threshold detectors separately to provide separate in phase pulses which are applied to a coincidence gate to provide an output. Amplitude modulation is rejected because it produces out of phase signals and frequency modulation is rejected because the transmission line is substantially flat. The RF generator may be frequency modulated and the output of the coincidence gate is applied to a shift register to insure the triggering thereof by only a true Doppler signal.