Abstract: A tape transport control system for monitoring the amount of tape on a tape reel using a first transducer means to provide a signal representative of the rotational speed of the tape reel. A fixed frequency oscillator is arranged to provide signals to be counted by a programmable variable modulo counter. The counter is programmed to start a countdown at a count preset by a digital word applied from a speed control selector for the tape transport. An output signal from the counter indicative of a fully decremented count status is applied to a two input AND gate which has as a second input signal an output signal from the reel transducer. An output signal from the AND gate is applied to the speed control selector to produce an interruption of an energizing signal to a capstan motor drive.

Abstract: A calorimetric apparatus for determining the calorific content of a fuel gas uses a reactor for producing oxidation of the fuel gas and a combustion gas in the presence of a catalytic oxidizer. The catalytic oxidizer is mounted on one end of a thermo-electric element which element has a heat absorbing end and a heat emitting end when energized by an electric current to produce a Peltier effect. The catalytic end of the element is mounted within the reactor while the other end is located outside of the reactor. The temperatures of the ends of the element are detected by a controller and the difference therebetween is maintained at a predetermined level during the catalytic reaction by the controller developing a control signal to control the supply of the electric current to the element. A display control signal is derived from the control signal by the controller and used to control a display for indicating the calorific content of the fuel gas.

Abstract: An adjustable overload mechanism for a differential fluid pressure transmitter includes a first and a second overload control diaphragm and an adjustable spring pressure means for applying an adjustable preload pressure to the control diaphragms. The spring pressure means for each diaphragm includes a spring such as a Belleville washer spring located between a diaphragm back-up plate in contact with a side of the control diaphragm and a wedge shaped support for the Belleville washer spring. A wedge shaped drive means is arranged to be selectively movable with respect to the wedge shaped spring support while maintaining the sloping wedge surfaces in contact. An adjustable drive screw is connected to the drive wedge to provide a means for changing the relative position of the support wedge and drive wedge.

Abstract: A calorimetric apparatus for determining the calorific content of a fuel gas uses a reactor for producing oxidation of the fuel gas and a combustion gas in the presence of a catalytic oxidizer. The oxidizer is heated by a constant current supply to a catalytic oxidation temperature. The resistance of the catalytic device is measured before and during the oxidation reaction which produces an additional heating of the catalytic device. The change in resistance is used to control a valve arranged to determine the flow rate of the fuel gas to the reactor. A display control signal is derived from a valve control signal and used to control a display for indicating the calorific content of the fuel gas.

Abstract: A unitary thick film resistor structure includes a first thick film resistor element formed on one face of a substrate and a second thick film resistor element formed on the opposite face of the substrate. The resistor elements are of complementary, substantially equal and opposite temperature coefficient of resistance characteristics such that when the two elements are connected in parallel to form a unitary structure, the opposite temperature coefficient characteristics provide a stable, mutually compensated low net temperature coefficient of resistance, and exhibiting an immunity to subsequent baking operations incident to the provision of a sintered protective outer coating.

Abstract: In a data protection apparatus for a multiple CPU system having a common or multiported bulk memory, an interface structure is associated with each of the CPU's. The interface structure cooperates with a firmware engine which is, in turn, a part of the interface control means which controls the transfer of data between the common bulk memory apparatus and each of the several CPU's in the system. Signals generated by the individual CPU's indicative of an emergency situation are applied as input signals to the interface structure. The interface structure then translates those signals into an attention flag signal and signals identifying the source or nature of the emergency. The firmware engine then responds to those signals and effects the necessary measures to protect the data relative to the affected CPU.

Abstract: A programmable digital memory circuit uses a programmable read only memory (PROM) to correct code errors and permit expansion to additional PROM chips. Each code correction or expansion is made via enabling a portion of an overlay patch programmable read only memory (PROM) for a similar portion of the memory circuit at an address code burned into the overlay trap (PROM). Initially the overlay trap PROM is unprogrammed, and each bit location therein can act as an enable/disable selection to a 32 byte block in the overlay patch PROM. When a bit in the overlay trap PROM is programmed and when the memory address selects that location, the main memory is unselected and the patch PROM location is selected, i.e., substituted. The 256 bit locations in the overlay trap PROM can select 256 32 byte patches in the patch PROM for substitution in the main memory.

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: 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: Apparatus for determining the composition of mercury-cadmium-telluride or other alloy semiconductors by using a four-photon mixing phenomenon. Means are provided for a pair of colinear laser beams of different optical frequencies such that the colinear beams passed through a sample of Hg.sub.1-x Cd.sub.x Te or other alloy semiconductors to produce emissions beams of the original incident optical frequencies and two or more additional optical frequencies formed by an electron spin-flip interaction. A magnetic field means is employed for varying a magnetic field across the sample during passage of the colinear beam from the points substantially below to substantially above the resonant field of the sample to produce a spin-flip signal which has a peak amplitude. Detector means are adapted to receive the emission beams to identify the spin-flip signal peak from which the spin-level splitting factor can be measured. Upon measurement of the spin-level splitting factor, the value for x can be calculated in Hg.sub.

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 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: 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: 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.