Abstract: A relatively simple circuit for implementing a low-cost, low power, highly accurate capacitance-to-voltage converter by which to measure the unknown capacitance of a capacitor. The circuit is characterized by the ability to eliminate error due to stray capacitance sources. The circuit is implemented by a crystal controlled clock generator which produces multi-phase clock signals to control the operation of a pair of series connected field effect transistors and a buffer amplifier. The field effect transistors are alternately switched on and off to periodically charge and discharge the capacitor under measurement between a source of reference potential and the inverting input terminal of a precision operational amplifier. The output voltage of the operational amplifier tracks the capacitance of the capacitor under measurement, such that an accurate indication of its capacitance is obtained by merely reading the output of the operational amplifier.

Abstract: A magnetic/electric field measuring device is disclosed, which is provided with an electron beam generator for generating an electron beam finely focused; a sample table, on which a sample is placed; electron beam deflectors for sweeping the electron beam two-dimensionally along an end surface of the sample; two-dimensional semiconductor position detection element using a photodiode for detecting the incident position of the electron beam, which has passed along the end surface of the sample; and a display section for displaying the position signal coming from said two-dimensional semiconductor position detection element in synchronism with a scan signal for the electron beam.

Abstract: An apparatus and method for determining which one of a plurality of circuit breakers in a breaker box controls a given electrical outlet supplied by one of the circuits emanating from the breaker box. A transmitter is plugged into the electrical outlet of interest which imposes a low frequency RF signal on the power line. The transmitter includes an indicator for indicating whether power is present at the outlet of interest. A receiver is plugged into a second electrical outlet near the breaker box, the receiver being configured to detect whether the low frequency RF signal is present at the second outlet, and includes an indicator to indicate whether the signal is present at the second outlet. The receiver also includes an indicator for indicating whether power is present at the second outlet. Each of the circuit breakers are turned off and back on in sequence until the circuit breaker is found which causes the receiver signal indicator to go off, while the receiver power indicator remains on.

Abstract: A detecting element (6) comprising a solid zirconia electrolyte (6a), a reference electrode (6d), a detecting electrode (6c) and a diffusion member (6a) is provided, and also a driving circuit (1b, 4) for impressing a voltage between the electrodes (6c, 6d) of said detecting element so as to detect the threshold current of an oxygen ion pumping current (I.sub.p) is provided. The output of this driving circuit is delivered as a continuous output (V.sub.o) of an air fuel ratio of fuel gas comprising al the regions of rich, stoichiometric and lean air fuel ratios. On the other hand, an I.sub.p detection resistor (Rs) for detecting the pumping current flowing between the input/output terminals of the driving circuit is provided. The opposite-end voltages (V.sub.a, V.sub.o) of this I.sub.p detection resistor are compared by a comparator (5), and a step signal corresponding to the stiochiometric air fuel ratio (.lambda.) is outputted from this comparator.

Abstract: A load monitoring, indicating, and alarm system monitors electrical continuity through an AC electrical load coupled in a first electrical line with an electrical indicator such as an indicating lamp in a second electrical line coupled in parallel with the first electrical line. A first AC electronic switch such as a triac is coupled in series with the indicator in the second electrical line. The actuating gate of the first AC electronic switch is coupled to the first electrical line. The first AC electronic switch is therefore conducting and the indicator lamp on when there is electrical continuity through the load and power is being supplied to the load. A reactance control component is coupled in series with the load for adjusting the phase angle of gate current to voltage delivered to the gate terminal of the first AC electronic switch. The reactive component may be a second AC electronic switch coupled in series with the electrical load in the first electrical line.

Abstract: A reset coordinated fault indicator for indicating the occurrence of a fault current in a monitored conductor includes an electrically actuated indicator flag. A trip circuit within the fault indicator impulses the indicator flag from a normal reset-indicating state to a fault-indicating state following the occurrence of a fault current in the conductor. A reset circuit periodically impulses the indicator flag to the reset-indicating state upon restoration of power to the conductor. To preclude simultaneous actuation of the trip and reset circuits and consequent failure of the indicator flag to register a fault, the trip circuit, upon the occurrence of a fault, first actuates the reset circuit to render the reset circuit inoperative, and then actuates the indicator flag to provide a fault indication.

Abstract: A floating driver circuit. A power supply is connected through a signal source to an amplifier's input terminal. The power supply is also connected to a pair of power supply terminals of the amplifier, via at least one resistor for each power supply terminal, so that direct current flows from the power supply into the power supply terminals. Further, at least one capacitor is connected to each power supply terminal. A cable, preferably coaxial, has first and second conductors. The first conductor is connected to a signal output terminal of the amplifier. The second conductor is connected to the power supply terminals through the capacitors. A pair of these circuits is combined at opposite ends of an electrical component to enable measurement of the impedances thereof.

Abstract: In a level measuring device for electrically non-conductive liquids comprising a sensor which is positioned in a vessel and is in contact with the liquid, and further comprising an evaluation circuit connected to this sensor both compensation of a changing dielectric constant and a high degree of accuracy and resolution are achieved by placing a driver electrode 5 in the lower part of the vessel 1 at a position essentually coaxial to the sensor electrode 3, 4, and by placing a compensating electrode 6 between the driver electrode 5 and the wall 8 of the vessel 1, such that further capacitors are formed between the two electrodes 5 and 6 themselves as well as between them and the sensor electrode 3, 4 and between them and the wall 8 of the vessel 1.

Abstract: The ratio C.sub.1 /C.sub.2 between the capacitances of two capacitors is obtained by connecting them into the frequency-determining circuit of an oscillator in at least three different combinations, namely C.sub.1 along, C.sub.2 along and both or neither of C.sub.1 and C.sub.2 ; the resultant oscillation frequencies are measured, and a signal representative of changes in C.sub.1 /C.sub.2 is derived from the oscillator frequencies, preferably by means of digital circuitry. In one preferred mode C.sub.1 /C.sub.2 is obtained by forming signals proportional to ##EQU1## and in another preferred mode proportional to ##EQU2## In still another preferred mode C.sub.1 /C.sub.2 -1 is obtained from the expression T.sub.1 -T.sub.3 /T.sub.2 -T.sub.3 and used as the indication of changes in C.sub.1 /C.sub.2. In the foregoing, f.sub.1, f.sub.2, f.sub.3 and f.sub.4 are the oscillator frequencies produced respectively by connecting C.sub.1 alone, C.sub.2 along, neither C.sub.1 nor C.sub.2, and both C.sub.1 and C.sub.

Abstract: A plurality of electrically conductive plates, preferably ring-shaped, are spaced from one another and electrically insulated from a conventional conductive probe rod, but movable therewith. The sizes and spacing of the plates are selected to provide a desired variation in capacitance between the plates and the object as the probe rod and the plates are moved toward the object. The capacitance between the probe rod and the object also increases as the probe rod moves toward the object. By appropriately combining these two capactiances, a nearly consant net capacitance occurs when the probe tip is very near a desired distance from the object, for a range of object sizes.

Abstract: A battery check system for a device which can be supplied with power either from a battery pack or from a D.C. plug adapted to be connected to an A.C. source by way of an AC/DC converter is provided with a large current load check mode for checking the supply voltage under a large load condition and a small current load check mode for checking the supply voltage under a small load. There is provided a mode switching means for setting the mode of the battery check system to the large current load check mode when said device is to be supplied with power from the battery pack and to the small current load check mode when said device is to be supplied with power through the D.C. plug.

Abstract: A hot cathode ionization gauge with which neutral gas densities in the ra 10.sup.17 to 10.sup.21 m.sup.-3 can be measured, in particular under the conditions typical of fusion-orientated plasma experiments (magnetic field strength from 0 to more than 3 tesla, magnetic field direction varying by up to +/-20 degrees or more and strong plasma-induced noise background), and which is of robust design, reliable in operation and very compact and has a high sensitivity which depends in a reproducible manner on the magnetic field strength and is independent, in a certain degree which is predetermined and can be influenced by the construction, of the field direction and, within a wide range, of the gas density comprises the following electrodes arranged in mutually spaced relationship in the stated order along an axis: a cathode consisting of a tungsten wire at least 0.

Abstract: A contacting thickness gauge for measuring the caliper of paper includes a U-shaped pole piece on one side of the paper with a return path being provided by a simple ferrite slab on the other side where the magnetic reluctance of the gaps provides a measure of the caliper. The pole piece has one leg of relatively small diameter contacting the paper; the other larger leg of the U-shaped pole piece being spaced from the paper by either jewel or air bearings to minimize the contact with the sensitive surface of the moving sheet material. The area ratio provides for an insensitivity of the gap of the large leg. In addition, the stray self inductance of the windings is eliminated due to the use only of a mutual inductance measurement to determine the final resonant frequency which is a measurement of the caliper.

Abstract: A combination caliper/moisture sensor in the form of a scanner in the cross-direction of sheet material being manufactured by a papermaking machine includes a pair of capacitive plates on opposite sides of the moving sheet material and in substantial contact with it which are utilized for measuring capacitance between the juxtaposed plates which are spaced in accordance with the caliper of the paper. Then a magnetic circuit which provides a flux path through the paper is utilized for measuring caliper which is the independent variable of the capacitance equation which, when solved, yields the dielectric constant. Since there is a known relationship between percent moisture and the dielectric constant, the percent moisture of the sheet material can be determined.

Abstract: A speed control system comprises a speed control unit and a test unit. The control unit has a Hall effect transducer for producing a signal representative of vehicle speed and a comparator for comparing that signal with a voltage reference source from which a control signal may be produced to control the vehicle throttle in the event of a disparity so as to maintain vehicle speed at a preset limit. The test unit is employed to set the voltage reference source.

Abstract: Non-magnetic metallic spacers are welded into the auxiliary air gaps of a voltage stator using welding passes arranged in a predetermined sequence. The presence of the spacers stabilizes the auxiliary air gap against change in light load adjustment. Sequences of welding passes are disclosed effective for holding inherent light load error at nominal values, or biasing it positively or negatively.

Abstract: Coupling unit for the operational monitoring of the high-voltage winding (SW) and the connected electric output lines in electric high-voltage machines and apparatus, particularly of three-phase stator windings in turbo-generators including their generator output lines (5.1, 5.2, 5.3) and/or in transformers and converters by means of determining partial discharges and measurement of the breaking spark in the high-frequency range, where the above-mentioned machines and apparatus are connected via generator output leads or other connecting line to each other and are connected to ground potential via network protection capacitors. The respective coupling unit (AE1, AE2, AE3) is coupled to one each of the three legs (5.1, 5.2, 5.3) of the generator output lead (5), and the network protection capacitor (C.sub.1, C.sub.2, C.sub.3) of each phase are connected to ground potential (B) via a measuring impedance. Furthermore, the shielded measuring lines (4.1, 4.2, 4.

Abstract: A machine for the automatic testing of electric motor rotors comprises a system for checking various characteristics of rotors arriving from a line of production thereof, in which system there are preset theoretical values of the various characteristics to be detected which are compared with the values detected on each rotor. Also provided in the machine is a display apparatus and/or a printer of the detected values, as well as a system of identification, in the tested rotor, of the type of characteristic whose detected value differs beyond an acceptable field of tolerance from the preset theoretical value.

Abstract: A gas sensor includes a pair of lead strips, a sensing element preferably comprised of a metal oxide semiconductor, such as SnO.sub.2, and extending between the pair of lead strips in the form of a bridge, a heater driver for supplying a heating current to at least one of the pair of lead strips, a detector for detecting a predetermined property of the sensing element, and a control circuit for controlling the operation of the heater driver and the detector. In one form of the invention, the detector is activated in a time period in which the heater driver is not activated. In another form of the invention, the pair of lead strips are connected in parallel or in series when the heater driver is to be activated. In a further form of the invention, the heater driver is normally operated periodically, but when the detector first detects a predetermined condition, the heater driver is operated continuously.

Abstract: A method for testing and measuring distortion in electrical devices is provided. For signal processing and carrying devices, a signal generator generates a signal having known phase, amplitude and frequency, which is provided both to a device under test and a measuring unit. The measuring unit measures the amplitude, frequency and phase rotation of an output of the device under test and provides these measured values to a suppression signal generator. The suppression signal generator generates a suppression signal which is added to the output signal from the device under test for suppressing the fundamental wave of the output signal. This suppressed signal is then provided to the measuring unit, for comparison with the original output signal from the device under test for determining distortion factors.