Abstract: The AFC gain of the local oscillator of an AM stereophonic decoder is linearized by the use of difference channel (L-R) information for controlling the capacitance of two varactor-type devices coupled across and in series with the oscillator inductance coil. The improvement helps to prevent "falsing" of the pilot tone indicator and the mono/stereo mode circuitry, particularly at the ends of the tuning range of a manually tuned receiver.
Abstract: After exposure to radiation photoresist may be developed by a dry process using a gas plasma, preferably an oxygen plasma. The process can be used for chemical milling, photolithography, printed circuit board and photomask manufacture and it is particularly advantageous in the manufacture of semiconductors. The plasma development process can be followed by plasma etch and strip processes without requiring removal of the work piece from the plasma reactor.
Abstract: A high-voltage power transistor is hereinafter described which is able to withstand fluences as high as 3 .times. 10.sup.14 neutrons per square centimeter and still be able to operate satisfactorily. The collector may be made essentially half as thick and twice as heavily doped as normally and its base is made in two regions which together are essentially four times as thick as the normal power transistor base region. The base region has a heavily doped upper region and a lower region intermediate the upper heavily doped region and the collector. The doping in the intermediate region is as close to intrinsic as possible, in any event less than about 3 .times. 10.sup.15 impurities per cubic centimeter. The second base region has small width in comparison to the first base region, the ratio of the first to the second being at least about 5 to 1.
Abstract: A peripheral interface adaptor (PIA) circuit for data processing systems contains memory elements or control registers allowing modification under program control of the logical functions of the PIA.A peripheral interface adaptor includes a plurality of data bus buffer circuits coupled to a bidirectional data bus and further includes peripheral interface buffer circuits coupled to a bidirectional peripheral data bus. A direction of data flow at the peripheral interface data bus is controlled by a data direction register. Data from the data bus buffer is entered into an input register, and is transferred from there to an input bus coupled to the control register, the data direction register and a data register. Data from the peripheral data bus the data direction register and the control register are transferred via the output bus to the data bus buffers.
Abstract: The IF amplifier combines the high frequency and low noise figure characteristics of a cascode stage with the large signal handling capability and accurate gain control of a direct emitter coupled amplifier controlled by a constant current source. The amplifier uses a technique of alternately stacked cascode stages which results in minimizing both the total current drain and the value of DC potential necessary to operate the amplifier. A current mirror, independent of power supply variation, is used to control the gain of the amplifier and is also used to provide temperature compensation for amplifier gain. Special bias techniques along with the current mirror minimize the variation of the amplifier gain with respect to DC power supply variations. Novel use of semiconductor devices minimizes the number of leadout connections on an I.C. chip needed for attaching large external bypass capacitors.
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: 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 method and apparatus for a thermal printer head which uses individual heater elements as switching devices is disclosed. The printer head consists of an array of individual resistors each capable of causing a dot to print on thermally sensitive paper. The use of heater elements as switches reduces the total number of lead outs required for the printer head. A system that uses such a thermal printer head is also disclosed. The individual resistor heater elements have a voltage-current switching characteristic which enables them to be used as switching devices in addition to their function as heating elements.
Abstract: A transistor switch having a square pulse with distorted leading and lagging edges and a distorted amplitude applied to the base thereof and the same pulse applied through two semiconductor junctions and a voltage divider to provide a voltage equal to the voltage applied to the base divided by one half with the voltage across a semiconductor junction subtracted therefrom and trigger the switch at one half the amplitude of the pulses applied thereto.