Abstract: A servo-system is provided for self-balancing systems using an ac servomotor capable of maintaining loop gain substantially constant irrespective of span adjustment and without capacitor coupling. It includes a direct-coupling dc amplifier for comparing input and comparison signals and amplifying the result, a servo amplifier having a differential direct-coupling amplifier with inverting and non-inverting input terminals, with feedback from its output to the inverting input terminal and a switch to the non-inverting input terminal operating at the same frequency as the ac power source for the servomotor, to maintain the loop gain constant irrespective of span adjustment, and means causing the ac servomotor to move a slide resistor to bring the compared signal into balance with the input signal.Provision is also made for receiving input signals from thermoelectric or resistance thermometers and balancing the system using these signals.

Abstract: To detect the density of a measurement component of a sample gas, infrared light is directed alternately through a measuring-light optical system and a reference-light optical system to a heated light sensor. The measuring-light optical system includes a sample cell, a first filter for transmitting infrared rays of a fixed wave-length band, and a temperature compensating cell having a gas which has a part of its absorption wave-length band within the transmission wave-length band of the first filter but has a spectrum different from the spectrum of the measurement component. The reference-light optical system includes a light throttle, an interference cell having a gas containing a fixed density of the measurement component, an adjustable-length interference compensating cell filled with the sample gas, and a second filter for transmitting rays of a wave-length band that includes the major part of the transmission wave-length band of the first filter.

Abstract: An effective-value converting circuit comprising a rectifier circuit of which four arms are composed of diodes to rectify an a-c input, a temperature compensating diode connected between the output terminals of the rectifier circuit in series with a plurality of resistance elements for principally determining break points, a resistance element whose one terminal is connected with one output terminal of the rectifier circuit and whose other terminal is connected with the other output terminal of the rectifier circuit through an integrating capacitor so as to determine the fundamental inclination of a broken line, and series circuits consisting of inclination-determining resistance elements and diodes connected respectively between the integrating capacitor and the individual voltage-division points of the inclination-determining resistance elements.

Abstract: Computations are performed on the digital representation of an analog signal in a digital processor. The output of the processor is applied through a digital/analog converter to a sample and hold circuit. The analog signal is applied to the processor through a comparator which receives at a second input the output of the digital/analog converter. In a mode other than the computation mode the processor controls an analog/digital conversion by means of a loop including the processor, the digital/analog converter, and the comparator.

Abstract: A two-color electrostatic printing apparatus capable of producing two-color images printed on a sheet of paper with two colored toners. The apparatus comprises a paper feed mechanism for driving the paper at a predetermined speed, a charging part for selectively forming positive and negative electrostatic latent images on the paper, a developing part for attracting positive-charged and negative-charged two colored toners simultaneously onto the latent images so as to render the latent images visible, and a fixing part for thermally fusing the toners attracted onto the electrostatic latent images.

Abstract: A detector to be inserted into a flowing conductive fluid, e.g. sodium coolant in a nuclear reactor, comprising at least one exciting coil to receive an a-c signal applied thereto and two detecting coils located in the proximity of the exciting coil. The difference and/or the sum of the output signals of the detecting coils is computed to produce a flow velocity signal and/or a temperature-responsive signal for the fluid. Such flow velocity signal or temperature signal is rectified synchronously by a signal the phase of which is shifted substantially .+-. 90.degree. with respect to the flow velocity signal or temperature signal, thereby enabling the device to detect voids in the flowing fluid without adverse effects from flow velocity variations or flow disturbances occurring in the fluid.

Abstract: An electric controller system includes a comparator at the input of a processor, the processor including a program memory, an operation control unit and a data memory. A digital/analog converter is provided at the processor output. Analog/digital conversion is by means of a loop including the processor, digital/analog converter and comparator. The digital/analog output is also received by an analog signal hold means, the output of which is fed back to the comparator. A manual control circuit operable only in a manual control mode provides an alternative input to the analog signal hold means. Computations in the processor are thus based on a manual input through the hold circuit and comparator only during the manual control mode. Bumpless switching from the manual mode to an automatic mode is provided while further providing for a manual output with failure of the processor. Further embodiments include a multiplexer at the input, a plurality of hold circuits and parameter setting circuits at the input.

Abstract: A thermal noise thermometer operating on the principle that the temperature of a resistor is related to the magnitude of the thermal noise signal produced in the resistor. The thermoseter comprises a temperature-sensing resistor, a shot noise source, means for selectively applying shot noise signals from the shot noise source to the resistor, a DC amplifier for amplifying the DC signal produced in the resistor, an AC amplifier for amplifying the AC signal produced in the resistor, and means for calculating the temperature to be measured from the output signal of the AC amplifier produced when the shot noise signal is applied to the resistor, the output signal of the AC amplifier produced when no shot noise signal is applied to the resistor, and the output signal of the DC amplifier.

Abstract: A simplified, compact, inexpensive portable self-balancing recorder to be used in the monitoring of data relating to pollution and/or environmental protection. The recorder is about 650 cubic centimeters in volume and weighs about 5 kilograms; it comprises a minimal number of constitutent components and may be operated without certain costly options (e.g. alarms and controls) if desired. The recorder uses printed circuit board circuitry to monitor and process input signals from the measuring points, and these components can conveniently and easily be removed from the recorder for adjustments or replacements. The recorder includes means for adjusting the ink pressure according to recording conditions and provides an inking system with an hermetically sealed pen point to prevent introduction of bubbles into the ink.

Abstract: A control system of the type used in process control and comprising a controller which provides a control signal on a signal line, and a DC output circuit for converting the control signal on the signal line into a DC current output signal varying in a range of, e.g., 4 to 20 milliamperes, which is supplied to a current loop including one or more load devices. The control system is characterized by open circuit detecting means for detecting an open circuit condition in the load current loop by detecting the fall of the DC current output signal below a predetermined minimum value, and shorting means in the DC output circuit for shorting the signal line in response to detection of an open circuit condition. Level detecting means are provided for detecting the shorting of the signal line, and thus an indication of an open-circuited load condition may be supplied back to the controller without requiring added signal carrying lines.

Abstract: A process control system of the type arranged to accept varied forms of analog sensing signals from field sensing devices, to digitally process data represented thereby, and to supply varied forms of analog control signals to field control devices. The system is characterized by signal converter means which convert data between the varied analog forms generated by the field devices and a standard form of intermediate signal, e.g., a pulse-width signal, which carries data as a function of duration. The intermediate signals facilitate signal transmission, editing, and isolation, and permit the process control system to have a simple, noise-free, easily adaptable structure. Digital interface means then convert data between the intermediate signals and digital signals in a form suitable for use by digital data processing means.

Abstract: A multipoint recorder of the type used to monitor a number of measuring instruments and including a mechanism having a group of contacts for sequentially selecting signals from a number of measuring points, a self-balancing circuit having a balancing motor for intermittently measuring each of said signals, and an indicating and recording mechanism operated in synchronism with said selection mechanism for indicating and recording, e.g., on a strip chart, the group of measurements supplied by said self-balancing circuit. The multipoint recorder is characterized by a group of auxiliary contacts in said selection mechanism interspersed with the group of measuring point selection contacts, said auxiliary contacts being switched with a given delay behind switching of the measuring point selection contacts so that the auxiliary contacts are sequentially closed as the selection mechanism switches between measuring point selection contacts.

Abstract: A differential-pressure transducer of the type comprising a measuring diaphragm supported at its peripheral edges and its sides presented to respective internal chambers filled with a pressure-transmitting liquid, the chambers and the diaphragm being contained in a body mounted within the interior space of an outer housing, there also being provided a pair of seal diaphragms remote from the measuring diaphragm and establishing liquid-filled isolation chambers communicating with said internal chambers respectively, the opposite sides of the seal diaphragms being adapted to receive the pressures whose differential is to be measured, and the peripheries of the seal diaphragms being secured to the housing.

Abstract: A process control system of the type arranged to accept sensing signals from field sensing devices, to digitally process data represented thereby, and to supply control signals to field control devices. The system is characterized by a centralized maintenance backup system for supplying backup control signals to selected field control devices while their normal control signals are interrupted during servicing of various system components, e.g., signal conversion units. A maintenance backup device, centrally located at a control station, includes means for providing an adjustable backup control signal, a selector unit having jack terminals connected through prewired leads to a plurality of field control devices, and jack plug means for connecting the backup control signal means to a selected jack terminal and the field control device corresponding thereto. Servicing of circuit boards used, e.g.

Abstract: A resonance thermometer utilizing nuclear quadrupole resonance, nuclear magnetic resonance or like resonance-absorption phenomenon. The thermometer includes an oscillator for oscillatively detecting a resonance in a resonant material, a means for modulating the oscillation frequency of the oscillator at a low frequency, a first detecting means with a short time constant for detecting a component from the modulated output of the oscillator, and a second detecting means with a long time constant for detecting a component from the modulated output of the oscillator. The oscillator frequency is swept in linear ramp fashion at high speed until an output from the first detecting means occurs, at which point the frequency sweep is stopped. The precise resonance-absorption frequency of the resonant material then is found by using the output of the second detecting means, and the temperature is derived from the precise resonance-absorption frequency.

Abstract: An analog-to-digital converter arranged to accept an analog input signal and to convert it into an output having digital form. The converter is characterized by a reference random noise source which generates random noise signals with uniform amplitude occurrence probability density in a given range, and by an amplitude comparator arranged to repeatedly compare the amplitude of the random noise signal with the amplitude of a signal varying with the analog signal to be converted. The amplitude comparator supplies output pulses in accordance with the comparisons, e.g., whenever the analog signal amplitude is greater than the random noise amplitude, and the number of pulses from the amplitude comparator in a measurement interval then digitally corresponds to the value of the analog signal and may be utilized, as in a display.

Abstract: A long-scale moving coil instrument of the type comprising a frame, means including an arcuate core member secured to the frame for forming a magnetic circuit path, and a mounting member carrying a moving coil over the core member and being suspended for rotation relative to the frame by means of tension bands secured to bosses on the mounting member. The instrument is characterized by a pair of boss-stoppers made of an elastic, electrically insulating material. Each boss-stopper supports a tension spring, lies in a through-hole provided in the frame, and has a central passage through which the tension bands extend for connection to the tension springs, the passages additionally receiving the bosses on the coil mounting member to limit movement thereof. With this arrangement, electrical connections to the moving coil may be effected by means of the tension bands while maintaining the electrical connections isolated from the frame with the electrically insulating boss-stoppers.

Abstract: A redundancy system for data communications upon two duplicate communication channels, each having transmission and reception circuits, characterized by a switching circuit for selecting one of said two communication channels, a single error detection circuit for detecting an error in the signal transmitted, and a control circuit for the switching circuit arranged to cause said two communication channels to alternately transmit signals when both the channels are in normal operation, and to cause one of said two channels to be selected when the other fails. The two channels share the error detection circuit and the control circuit and can therefore be built at a reduced cost and operated efficiently. Since the two channels are regularly checked for errors, they are operated with increased reliability.

Abstract: A graphic display device of the type which receives data and instructions from an external computer and displays graphic patterns such as alphanumeric characters, symbols, etc., upon a cathode ray tube in accordance therewith. The graphic display device has a pattern generator for storing luminance data controlling the formation on the cathode ray tube of predetermined patterns, and a refresh memory for receiving and storing data designating the particular arrangement of patterns to be displayed, and is characterized by an arrangement reducing the required capacity of the pattern generator memory.

Abstract: A digital controller comprises digital operating and processing means including an offering signal input terminal, an answerback signal input terminal, a data output bus, an input and output device designating bus, and a control signal bus; a plurality of output registers; a flip-flop circuit for storing an offering signal; a decoder circuit responsive to signals from the input and output designating bus and from the control signal bus to produce a control signal corresponding to a code signal for the decoder circuit when the code signal is designated and to reset an output register designated by a particular bit of the data output bus in response to a signal generated by a signal impressed upon the answerback signal input terminal to reset the flip-flop circuit for storing the offering signal; said plurality of register circuits being connected to receive an output signal from the operating and processing means designated by a particular bit of the data output bus; an offering signal holding circuit to hold