Abstract: An immersible liquid densitometer is disclosed employing an immersible vibrator. The vibrator includes one or two masses which are resiliently supported and which contain perforations which fill when the vibrator is immersed in the liquid. When the vibrator is immersed, the frequency of vibration is affected in proportion to the density of the liquid filling the perforations. Thus, measurement of the frequency of vibration may be used to determine the density of the immersing liquid. For maximum accuracy, the configuration and vibratory mode of the masses are selected for minimum energy coupling to the liquid. Typically, a cylindrical configuration is selected vibrating in a rotational mode. Under these conditions, the drag during vibration is due primarily to skin friction and a high Q, high accuracy measurement is achieved.

Abstract: The invention relates to an arithmetic unit fabricated by large scale integration techniques and to an improved digital network of increased accuracy in which the unit finds application. The integrated circuit comprises an initial summing means, rounding means, full precision multiplication logic and three successive summing means, all elements being successively connected, and all except the first having both internal and external input terminals. The unit is flexible in respect to the length of the operands and their sign notation. The terminals are readily cascaded, permitting interconnection of the unit with like integrated circuit units and with external delay elements. The invention is applicable in a variety of complex operations including digital filtering, correlation, convolution, polynomial evaluation and squaring. In many of these applications, mixed precision and rounding provide increased accuracy in the resulting digital networks.

Abstract: A smoke detector comprising a smoke detection cell of the ionization type and an electrical network which provides for ac operation of the detection cell. The impedance of the smoke detection cell is very high (40,000 megohms) and changes in the presence of airborne combustion products. The network senses the impedance change by a measurement of the current through the chamber assuming an ac source under a short circuit load condition, a technique facilitating the use of bipolar transistors.

Abstract: The invention discloses an ignition system control circuit which may be mounted within a distributor housing such as is used with internal combustion engines. The ignition system control circuit is coupled to a direct current source and appropriately connected to the primary winding of the high voltage generating coil of the ignition system. Current through the primary of the high voltage generating coil is controlled by a Darlington power amplifier, the conduction and non-conduction of which is appropriately synchronized to the engine. The control circuit includes a constant current source connected to a biasing resistor network of the Darlington power amplifier, and the constant current source supplies the Darlington power amplifier with a value of current to assure saturation of the Darlington power amplifier to allow maximum current to flow through the primary winding of the ignition coil notwithstanding substantial variations in voltage of the direct current source.

Abstract: A smoke detector comprising a smoke detection cell of the ionization type and an electrical network providing for a.c. operation of the detection cell. The impedance of the detection cell changes in the presence of airborne combustion products and alters the operating frequency of the network. The frequency change is sensed to actuate an alarm. A.C. operation avoids the problem of d.c. instability in the high impedance detection cell circuit and simplifies sensing the electrical condition of the detection cell. The electrical network typically uses MOS-FET devices as the active circuit elements.

Abstract: The present invention relates to a solid state imaging system in which pattern noise is cancelled both electrically and visually. Pattern noise takes the form of a succession of variable amplitude pulses occurring as each light sensing element in a row of elements is read out. The pattern noise is duplicated from row to row. Since pattern noise is initially many times larger than the video signal, it must be reduced to a fraction of the video signal for satisfactory imager operation. In accordance with the invention, a first video signal is formed in which each row of sensors is first scanned with video and pattern noise present followed by a second scanning with video absent and pattern noise present.

Abstract: An alarm driver is described providing an audio frequency signal for operating the alarm of a smoke detector. The driver comprises a four transistor bridge in which the transistor input bias is momentarily interrupted at an audio rate to permit the bridge current supplied to the alarm to stop and change direction. Cross coupling is provided to achieve bistability in operation of the bridge, while commutation is achieved by utilizing energy stored in the inductance of the alarm to turn one pair of transistors on and the other pair off at each switching transition. The driver is designed for maximum reliability and minimum current drain and it is suited for battery operation. It is preferably fabricated by an integrated circuit process, typically using bipolar transistors and sharing the substrate with the other circuitry of the smoke detector.

Abstract: A dc power supply system comprising two or more voltage regulator units connected in parallel to a common load, there being at least one more regulator unit provided than is required to meet the rated load current requirement. The spare or redundant regulator assumes the load automatically if another regulator fails, and does so in a manner such that it does not interfere with operation of other regulators when they are operating normally and such that its own operation is not affected by the others in the event of their failure.

Abstract: The present invention relates to an AM-FM receiver suitable for integrated circuit fabrication and having improved mode conversion means. The AM-FM receiver had a d.c. coupled IF broadband IF amplifier comprising a plurality of stages of emitter coupled transistor pairs. A d.c. feedback network is provided to balance the individual stages and to generate a control potential for further use in mode conversion. In the FM mode, the IF amplifier operates with a high, stable gain at the FM IF frequency with gain reduction for noise suppression purposes below the FM IF frequency. Frequency dependent noise suppression is provided by a capacitance associated with the degenerative network. In the AM mode, the IF amplifier operates at a controllable, medium gain with the degenerative effect on IF gain restored at the AM IF frequency by the addition of capacity to the degenerative network.

Abstract: Electronic apparatus is disclosed suitable for integrated circuit fabrication and comprising shunt voltage regulation. The electronic apparatus may be a radio receiver which uses an unregulated current source for its supply voltage. The power amplifier of the audio amplifier has a pair of conventional large area push-pull output transistors which are connected in shunt with the supply. In accordance with the invention, shunt voltage regulation of the supply voltage is achieved by sensing a change in the supply voltage using a zener diode for a voltage reference and then altering the idling current in the output transistors in response to changes in current flow through the zener diode. In consequence of increases in idling current, the output stages shift from class B toward class A operation and shunt regulate the supply voltage. The zener diode is arranged to provide both stabilization of the full supply voltage and the centering voltage of the push-pull output amplifier.

Abstract: 1. In an undesired signal canceller, a main signal transmission channel having an output terminal, a plurality of auxiliary signal transmission channels having output terminals, means for cross coupling each of said auxiliary channels separately to said main signal transmission channel, means for generating error signals representing the relative amplitude and phase of each undesired signal in the auxiliary channels cross-coupled with undesired signals in the main channel, compensating cross feed networks capable of adjustment for minimizing cross coupling at said main channel output terminal, and means responsive to said error signals for adjusting said cross feed networks in order to minimize cross coupling.

Abstract: A data acquisition system is provided for acquiring acoustic information from an array placed in a body of water and for transmitting the information through a single transmission line to remotely located data processing equipment. The array includes a plurality of sensors, a plurality of sub-multiplexers, a master multiplexer and an A/D converter. The sensors are arranged to receive acoustic signals from objects submerged in the water and each sensor provides an analog electrical signal representative of the acoustic signal received thereby. Each sub-multiplexer has a plurality of inputs and a single output with each of the inputs being connected to a corresponding one of the sensors. The sub-multiplexers sequentially sample signals received at their inputs from the sensors connected thereto and transmit these samples to a single output provided on each sub-multiplexer.

Abstract: This disclosure is directed to an Automatic Gain Control (AGC) circuit wherein the AGC loop which generates the gain control signal is separate from and not closed through the amplifier whose gain is controlled. Such arrangement permits design of the AGC loop to follow a sampled data reference signal and yet have a response time much shorter than the period between samples.

Abstract: An FM tuner having an improved automatic frequency control circuit and designed for use in an AM-FM receiver is described. The tuner employs a mixer transistor and an oscillator transistor connected in circuit so that they form a single series path across the bias source. This feature permits one to control conduction in both transistors by control of one and thus simplifies both biasing and mode conversion. Preferably, the transistor bias source and the source of AFC control potential are consolidated to save decoupling components. When the base of the mixer transistor is connected to the source through a low d.c. impedance, the AFC potential is transferred (less the mixer junction drop) to the collector of the oscillator transistor, where it provides sensitive automatic frequency control action. The circuit design uses a minimum of components.

Abstract: The present invention relates to semiconductor amplification means, which may be fabricated as a monolithic semiconductor structure, for use in an automatic gray scale control circuit for a color television receiver. During the blanking interval, the control circuit senses the cut-off voltage of each gun of a three gun color cathode ray tube and stores that voltage. During the video field, the stored voltage is used to energize the driver for the individual gun and to bias that gun. The AGS control function for each gun requires two amplifiers of high current gain, high inverse impedance, only one of which is on at a time, and a consolidation of the sensing and output functions in two terminals. These functions are achieved in a four transistor configuration in which two cascaded pairs of emitter follower transistor amplifiers are connected in a closed loop.

Abstract: The invention relates to an integrated arithmetic unit for computing summed indexed products and suitable for fabrication by large scale integration techniques. The arithmetic unit comprises a vector adder and a vector multiplier. The vector adder includes a pair of serially connected summers each with one sign controlled input. The vector multiplier comprises two single precision multiplication logics whose outputs are each provided with a sign control. The appropriately signed outputs of the two multiplication logics are then summed to provide the output of the arithmetic unit. The input data are introduced and the processed output data, both of which may be complex, are derived from the unit in bit serial, word parallel computation when a greater speed of computation is required and used repetitively with suitable multiplexing provisions when a lesser speed of computation is required. A major application of the arithmetic units is in the computation of multiple point Fast Fourier Transforms (FFT).

Abstract: The present invention relates to a novel automatic gray scale control circuit for a color television receiver. The circuit senses the cut-off voltage of each gun during the blanking interval, and uses a voltage equal to the cut-off voltage to energize the driver and bias the gun during the video field. The effect is to standardize the emission of each of the three guns against variation in gun cut-off voltage and to produce improved gray scale accuracy at the lowest emission levels. Since the gray scale adjustment is optimized at the lowest emission levels, where the eye is most intolerant to error in hue, one may avoid the need for manual adjustment of the cut-off point, and in cases where the gain does not vary widely from gun to gun, avoid the need for separate gain adjustment. Thus, the circuit may be used either to simplify or eliminate the color set up process at the factory when the receiver is manufactured. It may also reduce or avoid the need for readjustment after periods of use.

Abstract: The present invention relates to a regulated high voltage d.c. supply having an output voltage in the range of from 50 to 150 kilovolts such as is required for medical X-ray apparatus. The high voltage d.c. supply is constituted of a plurality of lower voltage d.c. to d.c. converter modules, whose output voltages are summed to produce the high voltage output. The converters are of a type which permits rapid activation and inactivation or "modulation". The modules are subjected to dynamic control to eliminate a.c. ripple, to regulate the high voltage output against supply line and load variations, and to turn the high voltage on and off in accurately timed intervals.

Abstract: A transformer designed to operate with a pair of power switching transistors in a d.c. to a.c. inverter is described. The transformer has an assembled core whose closed magnetic path is branched. A flux steering winding is used to ensure the prior saturation of a first branch associated with a regenerative feedback winding. Prior saturation of this branch reduces the forward drive on the switching transistors prior to full core saturation and avoids the consequent switching stresses on the transistors. The cores of the transformer are made from parts which abut at the branches so that both preformed power and preformed control windings may be used in assembling the transformer. The transformer may be assembled from conventional core configurations, and is thus of relatively low cost. A core arrangement is also disclosed in which the cross-section of the individual branches of the core may be adjusted.

Abstract: The present invention relates to an accumulation mode charge injection device utilizing the extrinsic photoconductivity of a doped semiconductor material to sense infrared radiation. The device is operated at cryostatic temperatures to preclude thermal ionization of the impurity sites and majority carriers are produced by IR photons interacting with these sites. The device utilizes a metal-oxide-semiconductor structure to accumulate the IR photon induced majority carriers at the semiconductor oxide interface under a first bias condition. When the bias is reversed the accumulated charges are injected into an output electrode. The sensor may be used singly or in arrays of similar sensors.