Abstract: Apparatus for turning off power-consuming appliances in rooms of a building having a private automatic branch exchange telephone system includes computer-controlled means at the exchange central periodically to apply short bursts of audio-frequency oscillations to telephone lines going to rooms in which power can be conserved. Detecting means in each room connected to the room telephone line provide an output on receipt of a burst which operates a line relay in the room, disconnecting power from the appliance in the room, for a predetermined time period greater than the time period between the periodic application of bursts at the exchange central.

Abstract: An eight-phase modem is described in which a 2900 H.sub.z carrier has eight phases each representing one of eight tri-bit symbols 000 through 111. The phase modulated carrier is restricted for transmission to a frequency band of 2900 .+-. 50 H.sub.z, and the modem can carry four time-division-multiplex 75-baud teletype channels at 250 bits per second at the upper end of a telephone voice channel without interfering with normal voice use of the channel. Or, the modem can carry eight channels at 500 bits per second in a frequency band of 2900 .+-. 100 H.sub.z. The modem operates reliably despite a carrier frequency translation or shift of up to .+-. 5 H.sub.z in the communications path. The modem extracts a carrier cycle spike from the received signal during each symbol period, and uses the spike to synchronize a locally-generated reference signal, and compares each spike with the reference signal to derive the corresponding phase-modulated tri-bit symbol information.

Abstract: A time division multiplex private automatic branch exchange includes a common interchange bus, and as many sampling circuits and associated recirculating shift registers as there are telephones. Two telephones are connected to each other through the bus when time-slot-determining outputs of the respective two shift registers actuate transmission gates in the respective sampling circuits. Other pairs of telephones may be connected to each other during other time slots. Additional sampling circuits and shift registers are provided to connect dial tones, ring tones, etc., over the bus to appropriate telephones in the same time division sampling fashion. All sampling connections are made under control of a computer by loading information into time slot stages of the shift registers.

Abstract: An article such as a plastic credit card contains concealed identifying information. The information is in the form of a series of binary information bits and it is stored in an electronic serial memory. The memory is on an integrated circuit chip imbedded in the credit card with electrical connections to two terminals on opposite surfaces of the card. The stored information bits are read out from the credit card by an apparatus which supplies current to the terminals to energize readout from the serial memory. The information bits read out are in the form of sequential variations in the current flowing to the credit card which are detected and accumulated in a shift register for utilization by a display device or a computer.

Abstract: A parallel-to-serial converter is described for use in translating a plurality of parallel line scan signals, derived from scanning a scene, to a serial signal suitable for application to a conventional television-type raster-scan display device. The parallel analog signals from a linear array of photodetectors scanned across a scene are simultaneously clocked into an equal number of charge coupled device (CCD) registers. The stored signals are later read out serially line-after-line and applied to a television type display. Two arrays of CCD registers are provided so that one can be loaded while the other is being read out. Each CCD register for a given line of video information consists of two parallel registers which alternate in receiving (and supplying) signals representing successive elemental areas along the line of the scene.

Abstract: The full-power condition of an internal combustion diesel engine is tested by an acceleration burst test in which the engine initially operated at idle speed is suddenly given full throttle and caused to accelerate to a maximum governed speed. A tachometer means coupled to the engine produces one electrical pulse per engine cycle. The time taken in going between a predetermined low speed and a predetermined high speed is accurately determined, despite irregularities in the engine, by adding a portion determined by interpolation in the time period between pulses at the low speed, and a portion determined by interpolation in the time period between pulses at the high speed, to the intermediate time periods.

Abstract: A flying spot scanner is disclosed for scanning an object document or scene with a spot of light, and producing an electrical video signal representing the object. The scanner can be operated under normal ambient light conditions without a light-shielding enclosure. A light beam is deflected in repetitive scanning fashion over the object. The light beam is modulated in amplitude (intensity) at a radio frequency f.sub.c such as 1.2 MHz. A photodetector is positioned to receive light from the object, and it produces an unwanted electrical ambient light noise signal having a maximum frequency f.sub.a, and an electrical information signal consisting of a carrier at frequency f.sub.c modulated by a video signal having a maximum frequency f.sub.m, where f.sub.c - f.sub.m is larger than f.sub.a. The information signal is separated from the ambient light noise signal by a filter, and the information signal is demodulated to produce a facsimile or video information signal free of noise due to ambient light.

Abstract: A tachometer includes a transducer for sensing pressure variations at the end of the exhaust pipe, or other easily-accessible point, due to explosions in an internal combustion engine. The transducer produces a corresponding electrical signal having a prominent selected frequency component which varies in frequency in direct proportion with engine speed. As the engine speed is increased and decreased, the electrical signal is passed through an amplifier with automatic gain control, and through a tracking filter to separate the prominent frequency component from other components. The separated component may be applied to a frequency-measuring device calibrated to display the revolutions per minute of the engine, or to a computer which computes and displays the result of an acceleration burst test.

Abstract: An engine diagnostic apparatus includes a transducer for translating an exhaust pressure waveform emitted by an engine to a corresponding complex electrical signal having a prominent fundamental frequency component which represents the cylinder firing frequency and varies in direct proportion with engine speed, and having a subharmonic frequency component at a frequency which is a submultiple of the fundamental frequency. The subharmonic frequency component and the fundamental frequency component are separated from the complex electrical signal and from each other. A comparator compares the amplitude of the subharmonic frequency component with the amplitude of the fundamental frequency component to provide a measure of the unevenness of power strokes from individual cylinders of the engine.

Abstract: A tracking band-pass filter useful for locking onto, and passing, an input signal which changes rapidly in frequency. The filter has a frequency pass band controlled by a voltage which is derived from the output signal passed by the filter. The output signal is translated from a sine wave to a pulse wave. The period between each two successive pulses is measured by counting the cycles of a oscillator during each respective period. An inverter translates the time-representing count signal to a corresponding frequency-representing voltage which is applied to the filter to control its frequency pass band.

Abstract: A system for controlling communications between a plurality of computer devices via a common bus. The bus includes a multi-conductor data bus and lines for busy, strobe and acknowledge signals. The system involves one universal interface unit associated with each respective computer device. Each device can initiate access to the common bus, through its respective interface unit, on a first-come, first-served basis.

Abstract: An apparatus for, and method of, detecting the uneven operation of the individual cylinders in an internal combustion engine, and for diagnosing the cause thereof. The engine is operated at any convenient idle speed. Power cycle time periods between successive ignition times are measured, the deceleration rates between successive time periods are then computed, and finally the average deceleration rates for the respective cylinders are computed. Misfires occurring randomly in cylinders are detected when individual deceleration rates exceed the average deceleration rate for the corresponding cylinder by a predetermined limit amount. Repeated malfunctioning in an individual cylinder is detected when the average deceleration rate for the weakest cylinder exceeds that for the strongest cylinder by a predetermined limit amount.

Abstract: Apparatus for and method of measuring the ignition timing of an internal combustion engine while cranking the engine with the starter motor, and with the ignition inhibited. Starter motor current fluctuations are examined to determine the times of current peaks due to compression in individual cylinders. Means coupled to the ignition circuit determines the times of points openings. A time difference signal representing the lead or lag of the ignition relative to the starter current peaks is generated. The lead or lag is then related to the time of top dead center in terms of degrees.

Abstract: Apparatus for and method of determining the brake torque and horsepower of an internal combustion engine without connecting an external load. Means are provided to operate the engine at full throttle and with all but one out of n of successive ignitions inhibited, the value n being selected so that the engine operates with just enough power to equal the frictional load of the engine and maintain an equilibrium speed at the upper end of the engine speed range. The engine is then operated momentarily with full ignition, and then with no ignition, during which a determination is made of the rate at which the engine decelerates through the equilibrium speed. The deceleration rate is multiplied by the known inertia of the engine to determine the friction torque of the engine at the equilibrium speed. The friction torque is multiplied by n - 1 to predict the brake torque of the engine at the equilibrium speed when operated normally with external load. Horsepower is determined by multiplying torque and speed.

Abstract: Satisfactory or unsatisfactory engine compression is diagnosed by comparing the amplitude of the starter motor current, when cranking an engine having its ignition inhibited, with a reference value. The reference value is adjusted in accordance with the intake manifold absolute pressure, as determined from measurements during the test of ambient pressure and intake manifold vacuum.

Abstract: A circuit for converting into parallel output data a serial input data stream including characters of N data bits preceded by a start bit at one logic level and followed by at least one stop bit at another logic level. A shift register of N+2 stages in one embodiment has all of its stages preset to a logic level corresponding to the at least one stop bit. The circuit detects the presence of a start bit on the input line and serially clocks into the shift register the start bit, the N data bits and the at least one stop bit. The circuit responds to the detection of the start bit in a particular stage of the register to provide a strobing signal to indicate the availability of a complete character in the register for parallel shifting out. After the character is shifted out in parallel each stage of the shift register is reset to the initial condition.

Abstract: Means for and method of testing the power of an internal combustion engine. A tachometer means coupled to the engine generates one electrical pulse per engine cycle of the engine. While the engine is full-throttle accelerated, a computer means measures the time periods between successive pulses, each time period constituting the reciprocal of the average engine speed during the particular engine cycle. One-half of the time period corresponding with a low speed and one-half of the time period corresponding with a high speed are added to the intermediate time periods to determine an acceleration time period which is a measure of engine power. The acceleration rate is determined by subtracting the reciprocal of the time period corresponding with the low speed from the reciprocal of the time period corresponding with the high speed to determine the speed change, and dividing the speed change by the acceleration time period.