A digital data demodulator for detecting binary information which is encoded upon an amplitude modulated or a phase modulated carrier wave. A specific example is presented for both a straight four phase and a modified four phase differentially coherent phase shift keyed (DCPSK) signal. The exemplary four phase DCPSK demodulator employs a discrete Fourier transform filter which provides updated Fourier coefficient values I + jQ during each sample interval. The I and Q values are rotated by 45.deg...

The disclosure relates to a phase and frequency discriminator which is especially adaptable to digital communication receiver systems. The discriminator consists of a duty cycle generator having two input terminals. Each one of the terminals is fed from a different pulse generator, and one of the pulse generators is activated by the input signal while the other is activated by the second input signal. One of the pulse generators activates the duty cycle generator while the other one deactivates ...

Disclosed is a servosystem including a servo motor which shaft is positioned in response to digital command signals. A comparator or error generator produces a pair of digital output signals respectively representative of an error magnitude and direction signal necessary to rotate the shaft in the desired direction to reduce the error, the digital output signals being converted to a bidirectional analog signal which is combined with a time derivative signal, the resultant signal being applied to...

Electronic governors for controlling the speed of prime movers wherein signals corresponding in frequency to actual speed and desired speed are compared to produce an error signal for controlling a prime mover actuator in accordance with the time integral of the period difference between the compared signals, the rate of integration and overall gain of the governor servo loop being completely independent of the actual speed of the prime mover. Alternative governors are disclosed which include dr...

A digital voltmeter wherein the DC voltage to be measured is converted into a linear current which in turn is converted into a proportional voltage used to drive a voltage tunable oscillator producing an output pulse train with a repetition rate proportional to the input voltage, a digital counter system being utilized to count the pulses and record the count on a digital display. In one embodiment, the voltmeter measures positive input voltages in voltage increments producing 1 Hz pulse rate ch...

Electronic governors for controlling the speed of prime movers wherein signals corresponding in frequency to actual speed and desired speed are compared to produce an error signal for controlling a prime mover actuator in accordance with the time integral of the period difference between the compared signals, the rate of integration and overall gain of the governor servo loop being completely independent of the actual speed of the prime mover. Alternative governors are disclosed which include dr...

A digital tachometer which is compact, highly reliable, and economically implemented with conventional circuitry including in combination with transducer means for generating a pulsed signal, a decade counter, timing means for determining a timing period, and control means whereby said counter accumulates count during the timing period. Display means receives and displays the count at the end of a timing period, and monitor means receives and compares the accumulated count with programmed set po...

A digital watch or timepiece with a cam disk seated upon a cannon pinion and provided with an indexing or switching cam for the stepwise indexing or rotation of an hour dial equipped with an indexing or pillar wheel. A security gear is rigidly connected with the pillar wheel, the security gear having teeth which are offset by one half of a tooth spacing with respect to the teeth of the pillar wheel. A circular security disk is rigidly connected for rotation with the cam disk, the security disk b...

A tracer for use with a profiling machine or the like has a tracer head which is excited with a source of alternating current to produce an output which varies in amplitude and phase in accordance with the direction and magnitude of deflection of the tracer stylus. The a.c. signal from the stylus is converted into a pulse encoded in time to be representative of the direction of stylus deflection. The time position of the pulse is converted into a digital representation of the angle of the stylus...

A plurality of number carrying blocks, each in the form of a rectangular parallelopiped, are supported in a display housing. The housing has a plurality of adjacent windows positioned at, and open to, mutually perpendicular block receiving areas. The windows are defined, in part, by generally angular wall sections arranged so that the blocks positioned in either one of the block receiving areas project through the windows. Two numbers are provided on each of the side walls of each body and a sin...