Abstract: Phase adjustment techniques are disclosed for use with signal multipliers and the like. A system and method is disclosed for producing selected phase relationship product values in signals which are to be multiplied electronically. In one embodiment, a signal is modulated and then delayed in time by digital shifter prior to multiplication with a second signal. Techniques are disclosed for producing any desired time delay by digital shifter. A system for producing a phase lead in a modulated signal is also disclosed.

Abstract: A communication system for use in a network of interconnected communication paths such as electrical power lines utilized for distributing electrical power. The system includes two or more remote units and a master unit, each having an associated address, which are connected to the network. The remote units are each capable of initiating a down link message sequence wherein a data package containing data, such as data relating to power consumption, is transferred from one of the remote units to the master unit. The down link message sequence may include the transmission of one or more messages containing the data package by the remote units with the particular path taken being a function of network conditions. The master unit acknowledges receipt of the data package by initiating an up link message sequence wherein the remote units transmitting during a down link sequence are informed of the receipt. In addition to addresses and data package the messages include information regarding network conditions.

Abstract: Apparatus and method for estimating a signal-to-noise ratio figure of merit of a received digitally-encoded binary sequence. The data sequence originates from a source which transmits the data with transitions between logic states at the source occurring only at predetermined epoch time points. The apparatus includes circuitry for producing transition signals whenever a transition is detected in the received data. Circuitry for generating reference signals from the received data indicative of the predetermined epoch time points of the transmitted data are also produced. The transition and reference signals are used to produce deviation data which represent the time difference between the transitions in the received data and the epoch time points. Typically, the reference signals are used to allocate the transition signals into deviation data groupings in accordance with the time in which the transition occurs. The deviation data groupings are then characterized to produce a figure of merit value.

Abstract: A telephone interrupter for use in a telephone system having low priority and high priority telephone equipment sharing a common telephone line. The low priority equipment is connected to the line by way of a bilateral switch. Sensing circuitry is provided for sensing when the high priority telephone equipment is in use and for causing the bilateral switch to automatically disconnect the low priority equipment from the line. When the sensing circuitry detects that the high priority equipment is no longer using the telephone line, the low priority equipment is automatically reconnected to the line.

Abstract: A system and method is provided for producing digital signals proportional to selected parameters of an input signal supplied to a modulator. The modulated output of the modulator is supplied to a delaying bistable circuit, and both the original output and the delayed output are then supplied to a gate, together with a clocking signal. The output of the gate includes pulses only when the modulated signal and the delayed modulated signal are simultaneously at the same level. As such, the digital output of the gate is a representation of the amount by which one level of the modulated signal exceeds the other, and is directly proportional to the magnitude of one polarity of the signal input to the modulator. Techniques are described for extracting digital signals proportional to the magnitudes of both the positive and negative half waves of the input signal, full waveform magnitude, and waveform offset and polarity.

Abstract: A modulator is provided for converting an analog input to an output pulse train having an average amplitude proportional to the input signal. The modulator circuit employs delta-minus-sigma modulation in which the output pulse train controls the selection of reference signals which exactly balance the input signal, over time. Instantaneous differences between the reference signals and the input signal are accumulated and measured by an integrator/comparator circuit. A high level of accuracy is achieved in the integrator/comparator because the system employs offset compensation to correct for voltage offset in one or more of the operational amplifiers. Several embodiments of the offset compensation system are disclosed. A method of modulation is also disclosed.

Abstract: A demodulator for frequency shift keyed carrier signals is described. A conditioned F.S.K. signal is simultaneously fed to a pair of rising edge triggered single shot voltage generators, such carrier signal being inverted prior to being fed to one of such single shots. The single shots are each triggered upon receipt of a cycle edge to initiate an output pulse having a duration falling between the time intervals distinctive of the cycles of the two possible carrier signal frequencies. The next rising edge received by each causes the respective single shots to retrigger, and latches the previous output of each into the first element of an associated serial memory device. The successive elements of each of the serial memory devices, store the state output signals of adjacent cycles of the carrier signal, with the states in one of such devices being one-half cycle apart from the states in the other.