Showing papers on "Clock generator published in 1968"

Data synchronizing system

Abstract: A system is described for acquiring incoming serial data, particularly of PCM code types, and establishing synchronization between the incoming data and a local clock generator. The system includes input signal conditioning circuits which applies the incoming data to a phase lock loop containing the local clock generator. The phase lock loop includes circuits for acquiring the input data and synchronizing the local clock generator therewith in spite of low signal-to-noise ratios and the loss of a large percentage of the input data bits in transmission. The local clock generator circuits include circuits which compare the phase of the clock generator output with the phase of the incoming data bits on a maximum likelihood phase estimate basis. The local clock generator outputs are applied to detect the incoming bits and reconstruct them into a noise-free output data stream.

Automatic musical rhythm system with optional player control

Abstract: An electronic rhythm device including a clock generator of adjustable frequency, controls for the clock generator to produce evenly or unevenly spaced output signals, a ring counter driven by the clock generator and having controls to bypass some of the stages of the ring counter, a plurality of sound generator circuits, connecting means comprising a plurality of resistor matrices connected between the outputs of the ring counter and the outputs of the clock generator and the inputs of the sound generators, and an automatic follow circuit to control the clock generator rate and an alternative automatic follow circuit.

Pulse train extractor system

Abstract: This system consists of a clock generator which controls the rate at which pulses of an incident pulse train are advanced through a shift register. The input to and the output of the shift register are logically combined in an AND gate. When the clock frequency is adjusted to be related to the pulse repetition frequency (PRF) of the pulses so that a pulse is in the last stage of the shift register at the same time that a succeeding pulse is received at the input thereof, the AND gate produces an output pulse. This operation is repetitive resulting in extraction of the pulse train.

Delay line control gated micrologic clock generator

Abstract: A delay line and logic control gated micrologic circuit clock signal pulse train generator with each pulse waveform clock signal in synchronism with its initiating gate trigger signal. A NAND gate receives an activating gate trigger signal and immediately a voltage shift in NAND gate output with this is then passed through a delay line coil both to output path means and also back as an additional input inhibit for the NAND gate at a predetermined delay determined by the delay line. The immediately resulting voltage shift at the NAND gate output is again passed through the delay line coil with the same delay to then remove the inhibit signal from the NAND gate with again an immediate shift in the NAND gate output voltage, and with the pulse generating cycle continually repeating itself with precise pulse width and spacing between pulses in a pulse train in synchronism although delayed from the start of the activating gate trigger signal with the pulse train cycle generating action continued just so long as the activating gate trigger signal is applied.

Capacitive intrusion detection system

Abstract: Each time the capacitance of a protected aircraft is charged to a prescribed threshold voltage level by a constant current source, it is discharged and an event or count is recorded in a first counter which automatically resets when it is full to repeat this operation cycle. The presence of an intruder near the aircraft causes its capacitance, and thus the time to fill the first counter, to change. An up/down counter is responsive to the outputs of the first counter and a clock generator for first counting up the number of clock pulses that are produced. When the first counter is half-full, the second counter counts down (subtracts) from the contents thereof the number of clock pulses that are produced prior to reset of the first counter when it is full. A decoder network monitors the remainder count in the up/down counter and initiates an alarm indicating intrusion of the protected aircraft area when the absolute value of the remainder count exceeds a prescribed minimum count at the end of any operation cycle. The system is reset at the end of each cycle.

Improvements relating to beamed energy control systems

Abstract: 1, 111, 865. Photo-electric machine control systems. FERRANTI Ltd. Nov. 21, 1966 [Aug. 28, 1965; Oct. 14, 1965], Nos. 37102/65 and 43545/65. Heading G1A. [Also in Divisions B3 and G3] The point of impact of an electron, ion or laser beam on a workpiece in beam cutting or welding apparatus is controlled by a servosystem which maintains the image of the light spot produced by the beam on the workpiece centred upon a photoelectric cell. Means are provided to vary the position of the image on the cell in response to a demand signal whereby the beam is moved in accordance with the demand signal. The light spot is imaged by mirrors 55, 56 on to the photocell system 21 which gives X and Y signals on leads 23, 24 indicative of orthogonal deviations of the image from a reference point on the photocell sensitive surface. The photo-cell system is mounted on a carriage 20, the position of which is indicated by X and Y pick-off signals on leads 33 and 34. The X signals and the Y signals are combined and control the X and Y deflection coils 17, 18 for the beam. The demand signal is arranged to move the carriage, and the signals applied to the deflection coils 17, 18, make the beam 13 follow the movements. If the image of the light spot is not in the sensitive area of the cell system, the summed X and Y signal on lead 25 is below a predetermined level and the unit 41 connects a scan generator 42 to the deflection coils 17, 18 to scan the beam until the image is in the sensitive area. Alternatively, Fig. 2 (not shown) the scan signal may be applied to the carriage 20, in which case, the pick off signals are disconnected from the scanning coils 17, 18. The carriage may be fixed and the demand signal applied to a mirror in the optical system between the workpiece and the photo-cell, Fig. 3 (not shown). Photo-cell circuitry. The photo-cell system 21 may be a four sided reflecting pyramid with pairs of photo-cells differentially connected and viewing opposite faces of the pyramid. Preferably, however, it may comprise a single photo-cell of the type in which an electron image of the spot may be oscillated across an aperture 71, Fig. 4, by coils 73, 74. Circuits produce, under control. of a clock generator 75, alternate positive and negative going triangular waveforms with the result that the electron image makes excursions across the aperture in the +X; -Y; -X; +Y directions in sequence. The pulses generated as the image moves out to the edge of the aperture in each of these directions are separated by gating circuitry synchronized by the clock, and the difference between the +X and -X pulses is smoothed by integrating amplifier 102 and forms the X signal on lead 23, Fig. 1. The Y signal is produced similarly. Automatic beam focusing. The focus coils 16, Fig. 7, are fed from a potentiometer 133 fed with a steady D. C. at its ends and an A. C. signal from an oscillator 136. The X+Y output from the cell on lead 25 oscillates with the variation of focus and is fed together with a reference phase from oscillator, to a phase-sensitive rectifier 141 to produce a D. C. error signal magnitude and sense dependent upon the deviation of the focus from its optimum. The error signal optimizes the focus by actuating a motor 135 to adjust the potentiometer tap 134.