Abstract: A directional coupler with a first and second transformer, having their primary windings connected in series, provides a sample of the current flow through the series connected primary windings. A third transformer provides a voltage sample of the voltage that results from the current flow through the primary windings of the first and second transformers. The voltage sample and the current sample are vectorially combined by a vector adder to obtain a first signal that is representative of the reflected power components of the current and voltage samples and also to provide a second signal that is representative of the forward power components of the current and voltage samples.

Abstract: An electronic meter is disclosed, for measuring functions such as power and energy of an alternating current and voltage. For measuring electrical energy, the meter includes an analog integrator for computing the integral of the voltage and of the current over a selected period of the voltage waveform. Means including a digital microprocessor and a comparison circuit are provided for generating a voltage level equal to the magnitude of the current integral or the voltage integral. In this manner, the microprocessor determines the value of the voltage or current integral. Since the integral of a sinusoidal waveform is related to its amplitude and to the power factor, the microprocessor can make a computation of energy from the values of the voltage and current integrals.

Abstract: A circuit is disclosed for coupling a power line communications signal between two three-phase power lines, with the signal being transmitted in a balanced phase-to-neutral mode on the first line and in a phase-to-phase mode on the second line. The circuit includes two coupling transformers, one open-wye to open-delta, and the other open-delta to open-delta. The primary of one of the transformers is connected to one of the three-phase lines, while the primary of the other transformer is connected to the other three-phase lines. The secondaries of the transformers are connected together at one terminal of each and interconnected by a capacitor at the other terminal of each. Signal and power voltage ratios between the two power lines are matched, and the capacitor is selected to provide series resonance in the secondary loop of the coupling circuit at the power line communications signal carrier frequency.

Abstract: A service tool is provided for a fiber optic connection system in which a pair of facing fiber optic connector ends are collinearly aligned by a tubular alignment insert therearound, all within an outer concentric tubular connection sleeve. After withdrawal of one of the connectors, the tool serves as an extraction tool for removing the alignment insert around the connector end within the outer concentric sleeve. The tool has another side serving as a test gauge for determining the presence or absence of the alignment insert around the end of the fiber optic connector within the outer concentric connection sleeve without looking into the sleeve.

Abstract: A system and method are disclosed for encrypting a voice signal. The input signal is filtered to provide a signal in a first path with components in a higher frequency band and a signal in a second path with components in a lower frequency band. Analog-to-digital conversion is carried out at a rate such that the frequency composition of the higher frequency path is inverted and shifted into the lower frequency band. Signals from the two paths are intermixed and converted to analog form at a rate greater than twice the rate of analog-to-digital conversion, so as to provide a randomized sequence of time segments of signals from the two paths, interspersed with gaps.

Abstract: A logical AND and logical OR gate are utilized in conjunction with two signals forming bits to be added for ascertaining the value of generate and propagate signals. The generate signal is passed to the output whenever the carry input is a logic zero and the propagate signal is supplied to the output whenever the carry signal is a logic one. This simplification of the approach to generating ripple carry signals substantially reduces the number of transistor to a value of about one-half that utilized in the prior art.

Abstract: A capacitive transducer is disclosed which provides a measurement of acceleration. The transducer includes a semiconductor element having a mass ring suspended from an elastic diaphragm which is retained by a support. The mass ring is formed to have opposed parallel planar surfaces, each of which are spaced adjacent a metal layer deposited on a glass substrate to form a capacitive circuit. The metal layers are configured in the shape as the flat surface of the mass ring and are coupled to provide an electrical output. The semiconductor element forms a common capacitor plate disposed between the two capacitor plates formed by the metal layers. Movement of the mass ring in response to acceleration causes a change in the spacing between the mass ring and metal layers thereby changing the capacitance and providing a measure of acceleration.

Abstract: A locking handle is provided for mounting a circuit card module to a card cage or rack. The module is released from the cage by pulling the handle to flex and bow the latter to a release position disengaging the cage to allow removal of the module. Upon re-insertion, the handle is pushed flat against the front edge of the module by the operator such that the operator need not push against the raw circuit card module edge. After insertion, the handle is translated downwardly to a locking position engaging the cage to prevent removal of the module.

Abstract: Synchronously clocked gating apparatus is illustrated for time multiplexing signals into and out of a register simultaneously whereby a single pin can be utilized for the two sets of data transfer rather than the two pins required in the prior art.

Abstract: A drop and insert channel bank is provided for receiving data from and inserting data onto a multichannel digital transmission line, such as a microwave radio link, between end terminals. The channel bank has a plurality of single channel units which share common equipment, including a receiver and a transmitter from and to the transmission line and a switching unit therebetween. The switching unit includes user controlled selection circuitry enabling any channel on the line to be dropped to any of the channel units, and enabling any channel to be inserted on the line from any of the channel units. Through-traffic passes through the receiver, switching unit and transmitter of the channel bank in digital form without conversion to and from analog form. Unidirectional and bidirectional modes are disclosed, including various forms of each.

Abstract: When a state machine such as a computer is inoperative, the flow of data can occur in so many different ways that it is at times difficult to ascertain the portions of the state machine that are causing the problems. Whether the problems are caused by original design or later failure of components, the present invention can determine at least the general area of the problem and often the specific bit introducing the problem, by setting a predefined control bit pattern into a register and ascertaining whether or not the bit pattern returned to the register after a predefined sequence of operations matches design expectations. As illustrated, this may take the form of serially inserting data into a normally parallel operated register to form the predefined control bit pattern, which then is applied to a sequencer whose output address is used to address a word in ROM, and the addressed word as well as the address itself, is loaded into the register.

Abstract: Circuits for bi-directionally bypassing a delta-wye transformer with a balanced phase-to-neutral power line communication signal, using passive components. The circuits include a set of three capacitors connected in a wye configuration, each having one side connected to one of the three-phase power lines on the delta side of the transformer. The circuit further includes a network connected from the node of the wye configuration of capacitors to neutral, the network including an inductive reactor with one side connected to neutral and the other connected to the node of the wye windings of the transformer. Component values are selected so that the circuit is resonant from the three phase lines on the delta side of the transformer to neutral. Further, the voltage transformation ratio of the communication signal from the delta side to the wye side is made the same as the corresponding power voltage ratio of the transformer.

Abstract: An improved microwave circuit is disclosed for enabling impedance tuning for power coupling in IMPATT diode and other similar oscillator and amplifier circuits. An electrically conductive support plate forming a ground plane is machined to form a channel for slidably receiving an air-stripline transmission line and a resonator therein. An IMPATT diode is positioned within the channel through an opening extending through the support plate generally perpendicular to the channel and is positioned in contact with the resonator. An electrically conductive bias filter is coupled to the resonator and to an adjusting mechanism for moving the resonator along the channel and providing a DC bias to the diode for oscillation. An electrically conductive cover member retains a spring biased electrically non-conductive projection for maintaining the resonator in contact with the diode.

Abstract: An extraction tool is provided for removing a locking latch from a snap-in socket of an electrical connector housing. The tool has a fork-like portion insertable into the socket for spreading the latter, and has an extendable hook portion for engaging and removing the latch from the connector housing upon spreading of the socket.

Abstract: An electronically tunable band reject filter rejects only frequencies of a signal that are in the reject band around its center frequency. The band reject filter includes an input directional coupler for sampling of the signal that is to be filtered and provides a first and second signal thereby. The first signal is filtered by a bandpass filter that passes only frequencies of the signal that are around the center frequency of the bandpass filter. An output directional coupler combines the second signal with the filtered signal and obtains on a difference port the difference between the second signal and the filtered signal. The frequencies of the signal that are centered around the center frequency of the bandpass filter are thereby rejected.

Abstract: Lookahead carry circuitry is provided for use with the consecutive bit stages of a digital adder whereby the computational throughput of an arithmetic logic unit can be increased (in other words reduced in time of operation). This is accomplished by reducing the number of gates required in the serial switching path to minimize the time delay for generation of carry output signals.

Abstract: Circuits are illustrated using CMOS design techniques for incorporating N and P channel transistors into a circuit to obtain the functions of exclusive OR and exclusive NOR signal generation. This is accomplished by utilizing a given logic value signal as a control signal to pass the other input signal for three of the four possible logic value conditions. The fourth condition must generate the output signal from a selected one of the input signals, through the use of an inverter.

Abstract: A transformer coupled DC-to-DC converter provides a regulated output with only one active switch. The converter includes a switch, a diode and an inductor coupled to the primary of a transformer in a way which provides symmetry to the transformer as the duty cycle of the switch changes for regulation. The circuit may be current-fed by supplying an input voltage higher than the transformer ratio would indicate, or may be voltage-fed by providing an input voltage lower than the transformer ratio would indicate. The circuit is operated to charge an inductor through the switch and half the primary of a transformer and discharge the inductor through the other half of the primary so that equal energy is provided through the transformer during charging and discharging, thereby providing a symmetrical signal without the need for more than one switch.

Abstract: An aircraft attitude indicator employing a gyro driven tape display. The tape takes the form of a closed loop stretched about a carrier mechanism, and includes a viewable horizon indication. The tape further includes a set of perforations which, preferably, are engaged and driven by sprocket teeth borne on a sprocket wheel member attached to the pitch gimbal of the gyro. The tape travels in response to tilt of the gyro spin axis relative to the aircraft, and in a direction so that reversed pitch sensing is accomplished.

Abstract: A variable voltage control oscillator can have its output frequency varied over a wide range of frequencies with a high degree of accuracy at each frequency and a rapid tune time is achieved when there is a reference signal source that runs at a constant frequency and is held to a high degree of accuracy and a counter for normalizing the output frequency of the VCO and a coincidence detector which compares the reference frequency to the normalized output frequency and provides an error correcting signal that adjusts the VCO to change the frequency very rapidly without having a frequency overshoot.