Abstract: A cleaning head for cleaning the slats in a window blind includes a manifold for receiving cleaning fluid, a plurality of spaced apart fingers arranged in a row on the manifold and at least one orifice defined in each finger for spraying the cleaning fluid onto the slats. Cleaning pads may be disposed on the fingers to contact the slats. The manifold may be divided to provide a source of vacuum to a second plurality of fingers with apertures defined therein for removal of excess cleaning fluid. Another embodiment of the cleaning head has couplings extending laterally from the fingers, and spacing elements may be interposed between the couplings to vary the spacing between adjacent fingers. Yet another embodiment of the cleaning head utilizes an enclosed compartment with slots defined in upper and lower surfaces for receiving a slat through the compartment.

Abstract: Apparatus for improving the performance of conventional electromagnetic reclosing relays under continuous lower magnitude ground or phase faults in electrical power distribution systems. An incomplete sequence relay is connected to the reclosing relay to render the timing drum or cam of the reclosing relay operative when the contacts of the circuit breaker are open, and to reset the reclosing relay after a selected time interval when the breaker is closed. This arrangement prevents timing problems associated with lower magnitude faults which otherwise keep the reclosing relay from reaching its lockout condition.

Abstract: A digital communication system including an encoder and decoder for the transmission of digital information over a transmission medium, the system having automatic frame synchronization and error correction requiring a minimum of tansmission bits and decoding time. The encoder processes a data stream and generates a transmission bit stream of N bits using convolutional encoding, autosynchronization sequence combining, and bit interleaving. The multi-phase sequential decoder decodes the received coded data, corrects transmission errors and automatically achieves frame synchronization from P selected phases of the received data. This is accomplished by selecting the phase of the received data with the best metric, bit de-interleaving, removing the autosynchronization sequence and comparing the received data of the selected phase with the extended code word subsets from the node having the best metric.

Abstract: An internally generated raster scanning circuit includes self correction for pincushion distortion by multiplying the horizontal parabolic wave form by the vertical saw-tooth wave form. The multiplier is biased to provide the required 180.degree. phase shift at the midpoint of the waveform. The multiplied signals are coupled back to an input of the existing power amplifier and a corrected current is then supplied to the vertical yoke coil, requiring no added reactor transformer. The balance or ratio of the top and bottom correction currents can be adjusted as required by a simple control in the multiplier circuit.

Abstract: This invention relates to a process for servo-controlling a magnitude TI depending on a parameter .theta., whereby: the variations in time of a second magnitude TG which varies as a function of the parameter .theta. and to which the magnitude TI is related are monitored; a control signal TGE=TDS+TER is provided, TER being a function of the deviation between the reference value TR and the real value TI of the first magnitude, and the value of TDS being equal to the arithmetical mean between maximum and minimum values, TGEMX and TGEMN respectively, of the second magnitude TG determined previously; and the value of the parameter .theta. is adjusted to servo-control the second magnitude TG by the calculated value TGE.

Abstract: An acceleration fuel enrichment system is disclosed in which if the rate of increase of throttle position is determined as exceeding a predetermined minimum threshold (V.sub.1), asynchronous acceleration enrichment fuel control pulses are developed and effectively added to steady state synchronous base fuel control pulses provided by an engine control microprocessor. When the rate of throttle position increase falls below a preset level, the development of the asynchronous fuel control pulses is terminated and synchronous acceleration enrichment fuel pulses are provided which are effectively added to the base synchronous fuel control pulses. The durations of these synchronous acceleration enrichment pulses are initially fixed, but when a decrease in engine manifold pressure is sensed, these durations are determined in accordance with the rate of change of the magnitude of sensed engine manifold pressure.

Abstract: Any offset error in the throttle position sensor reading of a fuel injection circuit can be corrected by determining the actual reading at a time when the reading should correctly be zero, then adjusting subsequent readings by the error figure. The error calculation is continually updated during periods of nearly-closed throttle, and is maintained between such periods. If the error exceeds a limit value, an "error" signal is provided.

Abstract: A television transmission system for asynchronously transmitting a television picture as a plurality of video samples over a narrow bandwidth medium from at least one remote transmitting site to a receiver at a base station. Improved synchronization between the transmitter and receiver are achieved by a dotting pattern consisting of alternating logic ones and zeros being sent by the transmitter to precede the video samples such that a sampling clock at the receiver synchronizes to the phase of the dotting pattern and thereafter samples the video signal. The video signals are also preceded by at least one predetermined digital word which identifies the particular remote transmitter and prepares the receiver to begin receiving the video samples. DC restoration circuitry determines the average value of the incoming video signals and to add an appropriate DC offset to the video signals to correct for any change in the gray scale of the video samples.

Abstract: The volume of gases in a container or the volume of liquid in the container is determined by creating cyclic pressure waves in the gases and detecting the waves by a second transducer. The signals produced by the second transducer are a function of the volume of gas in the container, and the volume of any liquid can be obtained by simple calculation. The signals can also provide detection of an open container and, when coupled to signals relating to the velocity of a vehicle, can provide other data such as a miles-per-gallon reading.

Abstract: A semi-duplex communication system provides high channel efficiency by having the base station transmit a reference signal which each terminal uses as a sync signal. Each unit having data to send to the base responds with a very brief signal such as a burst of silent carrier transmission during an assigned time slot in a queue of slots. Only those units which responded thus are polled during the subsequent polling cycle. During the transmission time slots, the base can be sending acknowledgments to those terminal units having sent messages during the previous polling cycle. While polling for data or acknowledgments or sending acknowledgments, the base can also be listening for the respective responses. The address code of a terminal unit is further encoded to carry other required information in both directions.

Abstract: A circuit providing a known change in a parameter of a function without interfering with the basic operation of the function is utilized in an audio circuit "loudness contour" control. Bass and treble controls function independently of the volume setting while desired contours are obtained at each volume control setting.

Abstract: A pushbutton tunable radio having an integral audio graphic equalizer is disclosed. During a tuning mode of operation for the radio actuation of any of five presettable pushbuttons results in the selection of a predetermined radio channel frequency within the AM or FM band, and a five digit display is provided indicating the selected channel frequency. During an equalizer mode of operation caused by actuation an equalizer mode selecting pushbutton, the radio remains tuned to the previously selected radio channel, but the frequency indicating display is now replaced by an electronic display indicating the relative emphasis of a plurality of subbands for the corresponding audio signals produced in response to the received radio channel. In the equalizer mode, actuation of any of the presettable radio pushbuttons results in selecting a corresponding one of the audio subbands for adjustment of its relative emphasis.

Abstract: A visual display mounting assembly is provided wherein a substantially rectangular parallelopiped central body 18 of a display module 17 is sandwiched between a planar surface 29 of a printed circuit board 23 and a substantially planar chassis wall 15 having a rectangular opening 16 therein for a front viewing surface 19 of the display module. The chassis wall opening 16 is formed with two opposing planar edge portions 32 of the chassis wall and two opposing nonplanar edge portions 33 of the wall comprising bent portions of the wall projecting towards the module. Peripheral portions 34 of the front surface 19 of the display module are positioned in pressure contact with the planar edge portions 32, and the front surface 19 is positioned between the non-planar edge portions 33 of the chassis wall. The display module 17 is held in place by retaining twist tabs 24 fixing the circuit board to the chassis wall and thereby having the circuit board press the display module body against the chassis wall.

Abstract: During engine cranking and after cranking if engine coolant temperature has not yet exceeded a minimum value, an air bypass valve (dashpot) provides maximum additional air to the engine fuel mixture in addition to the air provided in accordance with engine throttle position. During normal engine run conditions with the throttle not effectively closed, the dashpot provides minimum additional air to the fuel mixture. During deceleration when engine throttle is effectively closed, if engine speed is at least a maximum speed IDLEH and then declines, effective dashpot actuation will be 100% (maximum additional air) for engine speeds at least equal to IDLEH, 0% for engine speeds below a minimum speed IDLEL, and for engine speeds between IDLEH and IDLEL, the change (decrease) in dashpot actuation will be proportional to the change in current engine speed and substantially independent of time. If during deceleration engine speed decreases to IDLEL, then dashpot actuation remains at a minimum.

Abstract: A preconverged color display station is disclosed which is compatible with a computer controlled control unit that provides electrical convergence control signals. Compatibility is obtained by causing the control unit to transmit the electrical convergence signals to the screen storage memory RAM (random access memory) which normally stores information defining the character and character attributes to be visually provided by the display station CRT screen. The stored convergence signals are read back to the control unit from the screen RAM. After all of the convergence signals have been received by the display station and prior to the transmission of character and character attribute information signals to the screen RAM, the contents of the screen RAM is erased. Subsequently, the contents of the screen RAM, which now contains character display information signals, is read out and utilized to define a visual display on a CRT.

Abstract: A degaussing system in a CRT device detects a trigger pulse and provides a timed control pulse which controls a power circuit "on" time. The power supplied to the degaussing coil is gradually reduced by the increasing resistance of a PTC thermistor in series with the degaussing coil, then turned off by the end of the control pulse. Degaussing can be initiated manually or automatically as often as desired, and may be triggered automatically in response to a predetermined period of device inactivity.

Abstract: A remote unit can be controlled by sensing the change of impedance in the power line of a control unit as the control unit is turned on. The power line circuit includes a portion of an oscillator which is damped by the turn-on. Functions such as power turn-on and temporary audio muting are possible with minimal voltage drop in the power line.

Abstract: A scanning CRT visual display system is provided in which the operation of the CRT controller which provides video blanking pulses and horizontal and vertical sync pulses for controlling the CRT display is temporarily halted when a larger than normal vertical spacing between horizontal scan lines is desired. During the time that the operation of the CRT controller is halted, which is accomplished by the selective blocking of clock timing pulses to the controller, an auxiliary synchronous counter circuit effectively counts the clock timing pulses and provides a substitute horizontal sync pulse for the CRT display such that during the implementation of a larger than normal vertical step for the scanning CRT display system, horizontal sync pulses are always provided even though the operation of the CRT controller is temporarily suspended during this time.

Abstract: An atmospheric differential pressure sensor is disclosed comprising a pressure transducer, having a diaphram, mounted within a two piece protective transducer housing. An ambient atmospheric pressure receiving cavity is formed by the housing and coupled to the transducer diaphragm by a pressure transmitting tube that has a isolating oil drop within the tube to keep atmospheric contaminants away from the diaphram. The atmospheric pressure receiving cavity has external openings extending peripherally over more than 180.degree. of rotation about a central axis of said housing, and the ambient cavity provides a non-linear directional path between the end of the tube connected to the cavity and the exterior of the housing.

Abstract: One circuit, providing a feedback signal from the horizontal output transistor to the horizontal drive circuit, prevents damage to the output transistor in the event of a disruption or noise in the input signal, and also prevents "spot burn" of the CRT screen if the input signal should fail while there is still a charge on the CRT.