Abstract: A signal source which provides a carrier signal having a precisely set signal-to-noise ratio is provided. The carrier signal and its sideband noise components are attenuated below the equivalent thermal noise floor of an attenuator. The attenuated carrier signal and the equivalent thermal noise floor are then amplified in an amplifier having a known noise figure to produce a composite carrier signal having a usable power level and a precisely known signal-to-noise ratio. Since the equivalent thermal noise floor is a function only of temperature, the desired carrier signal-to-noise ratio may be set by setting the power level of the carrier signal and knowing the noise figure of the amplifier.

Abstract: An apparatus for measuring differential impedances which incorporates a CMOS timer in place of the sine wave generator in a typical AC bridge configuration. A toroidal signal transformer having its primary and secondary windings tightly twisted together and wound around the core lessens temperature drift characteristics. The differential bipolar current signal provided by the secondary winding is passed through an AC to DC converter which is switched by a field effect transistor, thereby eliminating the need for prior art inverter comparator circuits. Finally, by use of a bandpass filter after the signal transformer and by insertion of a capacitor before the AC to DC converter, the need for the active filter stage used in the prior art is eliminated.

Abstract: A cryogenic density and mass-flow measurement system incorporating a high-speed microprocessor-based cryogenic fluid density instrumentation that is based on the rigorous application of the molecular dielectric theory, using a dielectric susceptibility function in the application of the Clausinus-Mossotti formula, and the introduction of the quantitation of a new susceptibility parameter k which serves to bridge the gap between the theoretically rigorous molecular dielectric equation and the macroscopic dielectric equation. The operating principle is formulated on a differential dielectric measurement approach with a new algorithm which provides for automatic adjustments for polarizability and stray capacitance changes. High precision digital density measurement is achieved over a wide range of cryogenic fluid states ranging from supercritical through subcritical to the slush phase.

Abstract: A salinity measuring apparatus utilizes a specialized probe with dual electrode pairs, one of the pairs being used to pass current through the electrolyte, while the other picks up voltage drop across a region in the electrolyte and feeds it back to the current producing amplifier, which adjusts the current output until a stabilized, predetermined voltage difference occurs across the voltage electrodes. The circuit which drives the current between the current electrodes produces a positive pulse, and an ensuing negative pulse, which are sequentially applied across the electrodes so that two separate measurements are made using pulses of opposite polarity to cancel out electrode polarizations. An amplifier circuit receives a pulse from the voltage source and applies it to the electrodes.

Abstract: A fractional horsepower permanent magnet direct-current motor has a velocity indicating device positioned around the commutator, between the brush gear and the armature. The device comprises a conductor in the form of a square wave copper strip which is printed on a flexible support and centered on a circle about the motor shaft, and a magnet assembly mounted on the armature. Magnet assembly comprises radially extending blades which are formed from plastics bonded magnetic material. The blades are magnetized so that adjacent blades have opposite polarity. As the magnet rotates with the shaft, the blades move relative to the conductor and so induce an electrical signal in the conductor. The signal can be monitored to indicate the motor speed as is generally known. The blades also act as a centrifugal fan, helping to cool the motor.

Abstract: A circuit for testing a computer battery without removing it from the computer includes a plurality of serially connected resistors, and a transistor connected to saturate. The voltages at the junctions of the transistors is sensed by a logic device such as a buffer, for application to the data bus of the computer. The transistor may be controlled from the computer via a latch. The resistors have values to produce voltages at two sensed resistor junctions such that the corresponding logic levels applied to the computer are the same, at a first level, when the battery voltage is acceptable, are the same at another logic level when the battery voltage is unacceptable, and are different when the battery voltage is between acceptable and unacceptable voltage values.

Abstract: In a cross-coil moving-magnet measuring instrument having an approximately cylindrical core developed as winding form, a first coil and a second coil are wound crosswise one over the other. The second coil is necessarily arranged over the first coil in the region of the ends of the winding form and thus has a greater height of turn than the latter. Within the core there is furthermore mounted a moving magnet whose pointer shaft is brought out from an extension of the core. In order to reduce the errors in linearity of this measuring instrument and to permit a display over several quadrants, spacing elements are arranged on the core, they serving to guide turns of the coil, spaced from the extension of an core, around the latter in planes which are at right angles to each other.

Abstract: An instrument has a crossed-coil-type movable magnet in which a movable magnet rotatable about the shaft of a pointer needle is installed in a crossed coil unit and a measured quantity or the like is operated by supplying electric power to the crossed coil unit. The instrument includes an input unit to receive an input from a measurement object to be measured, an arithmetic section or ROM to set directions and time values for supplying electric current to the coils of the crossed coil unit, and a circuit section to deliver pulse signals with predetermined potential values to the crossed coils under conditions associated with the directions and time values, to provide a very broad angular range of the pointer needle.

Abstract: A self-contained electronic device for testing disparate storage batteries having any one of a fixed plurality of possible nominal voltages is disclosed. The testing device performs small-signal measurements of a battery's dynamic conductance and provides either a proportional numerical readout, displayed in appropriate battery measuring units, or a corresponding qualitative assessment of the battery's relative condition. Special voltage-sensing circuitry within the testing device identifies the particular one of the possible nominal voltages possessed by the battery and scales the dynamic conductance measurements accordingly. As a result, the quantitative or qualitative information provided to the user is automatically adjusted to comport with the nominal voltage of the battery undergoing test without the user having to actually input the battery's nominal voltage to the testing device.

Abstract: An impedance measurement circuit and method is disclosed that uses a differential amplifier to amplify a DC voltage value developed across a device being measured. The device is biased between potentials of a source of electrical energy by first and second bias resistors. A switchable current source is connected to the device to, when actuated ON, connect the device to the source of electrical energy through first and second associated resistors. The ratio of the values of the first to second bias resistors is substantially equal to the ratio of the values of the first to second resistors associated with the switchable current source. A microcomputer calculates the resistance of the device by subtracting the value of the output signal from the differential amplifier when the switchable current source is OFF from the value when the switchable current source is ON.

Abstract: Disclosed is a system for individually monitoring the condition of a single battery or each battery and related supply cables in a multi-battery battery pack. The system includes a means for positively indicating the condition of each battery in the battery pack. To monitor the condition of each battery, the system includes a means for comparing the voltage applied at the two terminals of each battery in the battery pack, and if this comparison reveals a deviation from a normal voltage difference, the system will indicate that the battery or related cables are faulty. For a properly operating battery the system will provide an indication that the battery is supplying the proper voltage, and when the voltage of any one of the batteries deviates from the standard, a system provides an indication that the particular batteries so deviate and will continue to show a deviation until reset even though the defective battery shows a normal voltage under a no load condition.

Abstract: This invention provides a polar device measuring apparatus which can bias a device under test in a proper polarity. The measuring apparatus is computer-controlled and automatically selects the polarity of the bias voltage based on the measured value of voltage across the device.

Abstract: A microwave system for determining the volume fraction of water in a fluid. In the described application, the fluid is crude oil, and the system is used to determine the volume fraction of water in the crude oil. A microwave beam having a frequency which varies with time is transmitted through the liquid, and absorption losses are calculated. The volume fraction of water is determined according to the absorption losses.

Abstract: A method for partial discharge detection and breaking spark measurement in a dynamo-electric high-voltage machine, especially for monitoring insulation status during operation of a stator winding and connected electrical output lines in a turbo-generator. The generator includes a stator having a stator winding and a stator housing, a rotor with an exciter winding and a shaft, defining an air gap between the rotor and the stator. At least one oil lubricated slide bearing supports the shaft of the rotor with a bearing shell being electrically insulated from the ground. The method includes decoupling the frequency spectrum of high-frequency electromagnetic oscillations resulting from the occurrence of partial discharges or breaking sparks and delivering the frequency spectrum of high-frequency electromagnetic oscillations to a partial discharge measurement apparatus.

Abstract: A method and an apparatus for determining angular velocity from two voltage signals which are produced by an angle transmitter (1) having a sinusoidal function with respect to the angle of rotation of a rotatable member and are shifted in phase by 90 angular degrees. The amount and sign of the angular velocity (.omega.) are determined by the division of the derivative of a first voltage signal with respect to time by the second voltage signal when said second voltage is above zero. In that signal range in which the second voltage signal passes below zero, the derivative of the second voltage signal with respect to time is divided by the first voltage signal. Alternatively, the amount of the angular velocity (.omega.) is determined from the vector sum of the derivatives of the two voltage signals with respect to time. The sign of the angular velocity is determined from the two voltage signals and their derivatives.

Abstract: Disclosed is a system for detecting and processing an abnormality in electromagnetic shielding for use in an intelligent building which is constructed using an electromagnetic shielding material for the skeleton and openings such as windows and doorways so that the whole of the building is formed into an electromagnetic shielding structure in order to carry out radio communication inside the building. The system has radio wave detecting means for detecting an external radio wave inside the building, level judging means for judging the level of an external radio wave detected by the radio wave detecting means, and processing means for detecting and processing an abnormality on the basis of an output from the level judging means, whereby an abnormality in the electromagnetic shielding performance is detected on the basis of the intensity level of a detected radio wave intruding into the building from the outside.

Abstract: A microwave system for determining the volume fraction of water in a fluid. In the described application, the fluid is crude oil, and the system is used to determine the volume fraction of water in the crude oil. First and second microwave beams, differing in frequency, reception location, or both, are transmitted through the liquid, and respective absorption losses are calculated. The volume fraction of water is determined according to the absorption losses. Different reception locations are used to detect the passage of a large slug of water.

Abstract: Disclosed is a radio wave leakage diagnosing system for use in an intelligent building which is constructed using an electromagnetic shielding material for the skeleton and openings such as windows and doorways so that the whole of the building is formed into an electromagnetic shielding structure. The system has a radio wave detector disposed outside the building for detecting a predetermined radio wave transmitted from each floor of the building, so that a floor, togethere with a specific position, where there is a leakage of radio wave is detected on the basis of the intensity of the detected radio wave. With this arrangement, a predetermined radio wave is transmitted from each floor of the building and the transmitted radio wave is detected by the radio wave detector.

Abstract: An apparatus for measuring the resistance in a closed loop electrical circuit without breaking or otherwise disturbing the circuit includes a detachable connector for joining the measuring apparatus to a closed circuit. The connector is linked to a circuit that induces, through the detachable connector, an electrical current in the circuit whose resistance is to be measured and then detects and displays the resistance of the tested circuit.

Abstract: A method and apparatus for detecting rotor faults in an induction motor. Such induction motors have a stator and a rotor comprising a multiplicity of rotor bars. The flux around the rotor bars is detecte at a predefined flux detection point in the motor, generally by using a coil wound around one of the stator teeth. A synchronization signal is generated once per revolution of the rotor when a predefined position on the rotor is closest to a stator reference point, usually the flux detection point. The detected flux signal is filtered to reject signals in a predefined frequency band around the frequency at which the rotor bars pass the flux detection point, and then it is synchronously time averaged. Averaging requires that corresponding portions of the flux signal, for a series of rotor revolutions, be added, and the synchronization signal is used as a reference for matching corresponding portions of the flux signal.