Abstract: A RAM assembly, or card, includes a random access memory portion for the data bits, as well as a random access memory portion for corresponding check bits. The card includes a parity generator and a parity comparator to determine the presence of an error. There is also included a decoder to decode the output of the comparator to determine the nature and position of the error. The error is not only corrected in the transmission to the central processor but is also fed back to correct the error in the RAM itself. Thus the errors that would appear in the RAM do not accumulate.

Abstract: In a control circuit to prevent the overheating of a conductively backed recording medium, a closed loop control circuit is provided wherein heat is provided to the heating electrodes of the circuit by one subcircuit under the control of a speed responsive control subcircuit. A feedback loop to a summing junction in the latter subcircuits is monitored to determine a deviation from virtual zero at that junction. A deviation from such virtual zero at that junction is used to control a shutdown safety circuit.

Abstract: An electrographic recording system includes means wherein toner powder having electrical and magnetic properties is carried from a hopper to a recording station by a rotatable drum or shell. The shell is rotated about a magnetic core structure which produces a magnetic field to hold the toner powder onto the surface of the shell as it rotates. At the recording station, a dynamic bridge is formed of the toner powder between the periphery of the drum and a magnetically permeable member positioned a predetermined distance from the surface of the drum. A record member is driven along a path between the drum and the permeable member with the reverse side of the record member in contact with the permeable member. An array of recording electrodes are positioned to be in electrical contact with the toner powder in the bridge. The record member is backed up by an electrically conductive platen.

Abstract: A gas analyzing apparatus for determining the BTU or calorific content of a combustible gas uses a radiometer or optical pyrometer for measuring the temperature of a metal cup black body heated by a flame produced by a combustion of the combustible gas in a gas-air mixture and a valve controller responsive to a control signal for adjusting the air-gas ratio, thermistors for measuring the temperature of the gas-air mixture and the ambient temperature and a temperature monitor including means responsive to the output signals from the radiometer and the thermistors to produce an output signal representative of the temperature difference therebetween and a peak detector responsive to the output signal from the temperature monitor means to produce the control signal for controlling the valve controller to obtain a peak in the output signal from the temperature monitor, whereby to obtain a maximum temperature differential between the metal cup and air-gas mixture with the attained differential temperature being an

Abstract: A computer interface console includes a cathode ray tube display, an operators keyboard, and an engineers keyboard. The engineers keyboard is so mounted that it may be moved to a position in front of the console in substantial alignment with the cathode ray tube and the operators keyboard when it is desired to make changes in the computer data base. At other times, the engineers keyboard is moved to a retracted position below the work space of the console, under the operators keyboard. In that retracted position, the work space is clear and uncluttered by the engineers keyboard. Additionally, with the engineers keyboard in the retracted position, it is unobstrusive and unavailable to unauthorized operators. Thus the probability of inadvertent or unauthorized manipulation of the engineers keyboard is greatly reduced.

Abstract: A housing for an electroacoustic transducer includes a filling or access port for introducing an inert liquid into the chamber defined by the housing. The access port includes a bubble trap and a vent for extracting gaseous bubbles from the fluid fill. The structure of the access port also comprises a substantially zero spring pressure expansion cavity for the fluid.

Abstract: An indicating and control apparatus uses Hall effect elements arranged on one side of a non-magnetic wall separating the elements from selectively positionable respective magnets. The magnets are selectively positioned adjacent to the non-magnetic wall to energize respective ones of the Hall effect elements by a code disc which is selectively positionable and displaceable with respect to the wall. The code disc is attached to a manually rotatable knob projecting from a housing enclosing the selectively positionable magnets and having a dial face on the exterior surface of the housing to cooperate with an indicator on the knob. The Hall effect elements, in turn, are located on a printed circuit board and are connected to associated circuitry to bias the Hall effect elements and to utilize output signals from the Hall effect elements.

Abstract: A gas analyzer for determining the BTU or caloric content of a combustible gas uses a temperature measuring device for measuring the temperature of a metal cup which is heated by a flame produced by the combustion of the gas in an excess air environment. The supply of combustible gas is periodically turned off while the air supply flow is maintained to produce a periodic heating and cooling sequence of the metal cup during fixed respective time periods. A differential temperature monitor is arranged to monitor the temperature of the metal cup and the incoming fuel and air to produce a differential temperature signal during the heating and cooling sequence. In a second embodiment, the gas flame is continuously ignited and is supplied from a rotating gas jet in the excess air environment. The flame is sequentially applied to a series of metal cups to produce a heating and cooling sequence of each cup.

Abstract: A sensor correction circuit uses a programmable read only memory (PROM) for storing characterizing information for an associated sensor or transducer. The information is stored in the 1.times.2048 bit configuration. The programmable read-only memory (PROM) has its parallel outputs connected to corresponding inputs of a 2048 bit shift register. The programmable read-only memory and the shift register are located in an electronic circuit housing, along with a power supply and sensor signal handling electronics, attached to the sensor structure to form an integral package therewith. An isolation interface is mounted on the housing and is connected between the circuit within the housing and an external data processing and interrogating system which may include a microprocessor.

Abstract: A circuit for removing the DC or background representing charge component of a signal to be retrieved from a charge-coupled device to individually compensate for variations of each charge-coupled device circuit. A threshold gate is interposed in a charge flow path between a charge integrating well and an output charge transfer gate. The threshold gate is connected to a potential level which is automatically adjusted to compensate for DC variations in a fixed level of the charge to be extracted from the integrating well. A feedback connection between the threshold gate and the integrating well adjusts the potential level during the integration of a reference charge between the integration of an information signal charge.

Abstract: A housing for an acoustic transducer includes means for dispersing internal reflections within the housing to minimize the incidence of such internally reflected acoustic pulses on the transducer itself, thereby avoiding the generation of spurious electrical signals for transmission to the translating circuitry.

Abstract: A voltage buffering coupling circuit for coupling a ground-referenced control signal to a high voltage biased CRT includes all solid state elements, thereby avoiding the tendency of the arc breakdown characteristic of gaseous voltage regulator tubes. The circuits include temperature compensating elements of opposite thermal coefficient characteristics.

Abstract: In a magnetic tape recording/playback system, there has here been provided a phase sensor circuit wherein a recorded square wave signal, when played back, produces a signal which includes a predominant first and third harmonic. A filtered sample of the relative amplitude of the resulting peaks is compared and a difference signal is indicative of a phase shift error. That signal may then be used to effect a control to correct the phase shift error.

Abstract: In a computer control system a central processor unit (CPU) is provided as a primary control center. A data bus interface controller is connected to interface between the CPU and a serial data communication bus. The interface control unit controls the traffic on the data bus as well as interfacing the format between serial data on the data bus and the parallel data receivable by the CPU. A plurality of process interface units are connected to the serial data bus. Each of these process interface units (PIU) has a plurality of process input/output devices connected thereto and controlled thereby. The PIU's exercise a significant amount of control capability including having an internal microprocessor unit. By performing many of the functions heretofore provided by the central processor unit, the PIU significantly reduces the amount of data which must be transmitted via the serial data bus to the CPU.

Abstract: A multivibrator circuit having a pair of capacitor cross-coupled transistors arranged to form a flip-flop circuit. The base and collector currents for the flipflop transistors are concurrently varied by respective current sources controlled by a multivibrator input signal. The circuit has a constant Beta requirement for the transistors over a wide frequency range while maintaining a high speed operation.

Abstract: A differential pressure to electrical signal transmitter has a pair of barrier diaphragms and a central control diaphragm located between the barrier diaphragms. Input fluids are applied to respective chambers on the outside of the barrier diaphragms while the chambers between the control diaphragm and the barrier diaphragm are filled by corresponding substantially incompressible fill liquids. The fluid pressure of the two fill fluids are conducted by corresponding fluid channels to respective sides of a displacement sensing element to produce an electrical signal representative of differential pressure. The control diaphragm is biased by spring loaded spacers located on corresponding sides of the control diaphragm. The spacers have fluid passages to permit the respective fill fluids to reach the control diaphragm.

Abstract: A fluid circuit device provided with a fluid circuit formed by a base member and a thin sheet integrally electrocast on said base member and methods for producing the fluid circuit device with parallel and non-parallel fluid circuits.

Abstract: A chromosome detector using a scanning microscope system is used to detect the presence of a chromosome spread in a slide specimen and to produce a signal usable by the scanning microscope system to automatically operate the microscope system whereby the detected chromosomes are centered in the field of view, are automatically focused and their location converted to coordinate data which is stored in a memory system whereby the system may be used to re-examine the detected chromosome by the use of the stored X-Y coordinates. The detector performs an amplitude and frequency analysis of a cell find signal produced by a slide scanner in the scanning microscope system and produces, in turn, an output signal representative of a detected chromosome spread and compatible with the scanning microscope control circuit.

Abstract: A signal isolator has an acoustic transmitting medium with a first pair of acoustic transducers thereon for transmitting an input signal through the medium at a first frequency. A first transmitting and receiving circuit is used in combination with the first pair of transducers. A second pair of transducers is located on the acoustic medium to transmit a power supply signal through the medium at a second frequency. Power supply means associated with the power supply signals are used to energize the transmitting and receiving means on opposite sides of the medium.

Abstract: An apparatus and method for separating components of a fluid mixture of materials uses an acoustic or sonic generator attached to one end of a hollow tube, or column having a uniform internal diameter, to produce standing sonic waves within the column. The sonic waves act as so-called chromatographic plates with the plate height being equivalent to the wavelength, and the plate number in the column being equal to the total number of nodes in the column. The effective column length can be controlled by the use of moving sonic waves which by changing the direction of wave motion can enhance or attentuate the separation process to produce a variation in the apparent column length without changing the physical length of the ultrasonic column. A sample to be separated and a carrier fluid are introduced into the end of the column adjacent to the sonic generator while a fluid exit is provided in the other end of the column.