Abstract: A calibration circuit of an AC/DC converter which measures an AC voltage by converting the AC voltage to a DC voltage. The AC/DC converter measures the AC voltage with high accuracy with low cost by having a calibration circuit to correct the frequency response characteristic involved in an AC/DC conversion process. The AC/DC converter includes a signal generator for generating at least two calibration signals having the same energy level and different frequency spectrums, a switch for selecting the input signal to be measured or one of the calibration signals from the signal generator, an amplifier for amplifying the selected signal from the switch wherein the amplifier has a circuit arrangement for adjusting a frequency characteristic thereof, and an AC/DC conversion circuit for converting an AC voltage from the amplifier to a corresponding DC voltage.

Abstract: An object oriented architecture is used within individual monitoring units. The monitoring devices include circuitry which receives an electrical signal and generates at least one digital signal representing the electrical signal. Objects within such individual monitoring units include modules which perform a function and registers which contain the inputs, outputs and setup information for the modules. Methods can be invoked on all objects to change or query the operation or configuration of the device. At least one of the modules receives the digital signal as an input and uses the signal to generate measured parameters. Additional modules take measured parameters as input and generate additional parameters therefrom. The module may be linked in an arbitrary manner to form arbitrary functional blocks.

Abstract: A control circuit which regulates an ac power output device. The control circuit is operatively connected to the ac power output and measures the ac signal with a diode to generate a control signal stimulus. A second diode is operatively connected to the power measuring diode so that the two diodes have the same voltage drops associated with the quiescent operation of the diodes. Quiescent voltage changes in the power measuring diode are canceled by the matching quiescent voltage change in the second diode. In this manner, power measurement errors associated with diode quiescent voltage changes are minimized.

Abstract: A power-on control circuit which functions to inhibit and prevent turn-on of an external power supply to an aircraft, unless a continuity signal is received from the aircraft indicating proper mating of the external power plug in the aircraft socket, thus preventing the hazards of an improper connection. The invention power-on control circuit incorporates a subcircuit for generating an acquisition signal to confirm continuity of connection, and a sensing and detector sub-circuit to enable turn-on of an external power source supplying power to an aircraft. The control circuit contains high ohmic isolation between logic elements and the aircraft, and is not sensitive to coupling with extraneous signals.

Abstract: An object oriented architecture is used within individual monitoring units. The monitoring devices include circuitry which receives an electrical signal and generates at least one digital signal representing the electrical signal. Objects within such individual monitoring units include modules which perform a function and registers which contain the inputs, outputs and setup information for the modules. Methods can be invoked on all objects to change or query the operation or configuration of the device. At least one of the modules receives the digital signal as an input and uses the signal to generate measured parameters. Additional modules take measured parameters as input and generate additional parameters therefrom. The module may be linked in an arbitrary manner to form arbitrary functional blocks.

Abstract: A load measuring device includes a sensor for detecting power consumption surges by detecting a zero voltage point in the alternating voltage of an electrical apparatus, detecting the zero current point in the alternating current of the apparatus least remote in time from the detected zero voltage point, and measuring the interval between the two zero points. The zero-current point is detected by a current sensor which comprises a first rectifier coupled in series with the apparatus, a second rectifier coupled in parallel opposition with the first rectifier, and a voltage sensor coupled in parallel with both rectifiers.

Abstract: A level measuring set for low-frequency signals with superimposed direct voltage includes a low-pass filter, a measuring rectifier, and a subtractor. A low-frequency measurement signal is supplied to the low-pass filter, which outputs a reference potential (U.sub.B) which corresponds to the direct voltage. The reference potential (U.sub.B) is applied to a reference point of the measuring rectifier. The measuring rectifier forms a positive and a negative direct voltage component (+U.sub.M, -U.sub.M) superimposed on the reference potential (U.sub.B) for the positive and negative half-waves of the low-frequency signal, respectively. The subtractor receives at inputs thereof the positive and negative direct voltage components (+U.sub.M, -U.sub.M) superimposed by the reference potential (U.sub.B) and emits a level measurement value of the low-frequency measurement signal.

Abstract: A power measuring system includes a transformer that produces a voltage signal in response to the presence of a changing current within a power cable. An input circuit is electrically connected to the transformer for receiving the voltage signal, and produces an analog current signal representative of the changing current within the power cable, in response to receiving the voltage signal. A transmission line has a first end electrically interconnected with the input circuit so as to receive the analog current signal and has a second end electrically interconnected with an output circuit located at a location remote from the first end. The output circuit receives the analog current signal and produces a resultant signal in response to receiving the analog current signal. The resultant signal may be used to provide a meter display. A housing for a sensing transformer having a split toroidal core is disclosed.

Abstract: A meter measures a voltage across a quasi-diode, the voltage caused by a current flowing through a resistance which changes substantially exponentially with changes in a medium being sensed. The meter comprises a logarithmic current measuring circuit coupled to the resistance to provide a measurement output that is a logarithmic function of the current flowing through the sensing resistance. A switchable current source is controlled by a switching circuit to repetitively output first and second current values. A reference logarithmic circuit is connected to the switchable current source and is physically coupled to the logarithmic measuring circuit so as to be maintained at a substantially equal temperature value. The logarithmic reference circuit manifests a first voltage in response to the first current value and a second voltage in response to the second current value, both voltage values dependent upon the temperature of the logarithmic reference circuit.

Abstract: A direct current booster device has a booster which includes a plurality of N-channel MOS field-effect transistors (FETs) each having a gate terminal and a drain terminal joined together and connected in series in the same direction from the input side to the output side, and a plurality of capacitors to which two boosting clock signals of an opposite phase are provided, which are generated by a clock driver circuit and supplied alternately in a one-by-one corresponding relationship so that the two different boosting clock signals are inputted to each pair of adjacent gate-drain terminals of the FETs. A test circuit is provided, which has a plurality of N-channel MOS FETs, the source terminals of which are connected individually to the gate terminals of the FETs of the booster.

Abstract: A wide power range radiation monitor includes a pair of diodes with their cathodes interconnected and with an additional capacitor coupled in parallel to one of the diodes. The detector, of the radiation monitor provides two outputs, a low power output and a high power output, which outputs are connected to the anodes of the detector diodes. The arrangement of dual diodes and capacitance provide the diode detector of the monitor with a greater than 40 dB square law region.

Abstract: A wide power range radiation monitor includes a pair of diodes with their cathodes interconnected and with an additional capacitor coupled in parallel to one of the diodes. The detector of the radiation monitor provides two outputs, a low power output and a high power output, which outputs are connected to the anodes of the detector diodes. The arrangement of dual diodes and capacitance provide the diode detector of the monitor with a greater than 40 dB square law region.

Abstract: A superconducting circuit system comprises a biasing circuit for producing a bias current that changes periodically, and a superconducting rectifier circuit driven by the bias current. The superconducting rectifier circuit is supplied with a first pulse train including therein positive and negative pulses in synchronization with the bias current and produces a second pulse train of unipolar pulses in response to a transition of a Josephson junction caused by the pulses of the first pulse train.

Abstract: A wide power range radiation monitor includes a pair of diodes with their cathodes interconnected and with an additional capacitor coupled in parallel to one of the diodes. The detector of the radiation monitor provides two outputs, a low power output and a high power output, which outputs are connected to the anodes of the detector diodes. The arrangement of dual diodes and capacitance provide the diode detector of the monitor with a greater than 40 dB square law region.

Abstract: The crest value and RMS value of a signal are measured. The ratio of the two values, the crest factor, is calculated to provide a measure of the signal wave shape. The frequency range and accuracy of a commercially available RMS converter is improved by providing an improved rectifier ahead of the converter's internal rectifier. This improved rectifier is also used to form the absolute value of the input signal. A peak detector then provides the crest value (absolute peak value). The crest value and RMS value are multiplexed to a computer having an A/D converter. The RMS value, crest value and crest factor can be calculated and displayed and/or stored by the computer.

Abstract: The present invention concerns a circuit processes the power signal emitted from an RF power sensor (SK) of a radio telephone to create a detector voltage which is proportional to the power level of the radio telephone transmitter. The circuit comprises a transistor (Q2) acting as an active rectifier, which in the ascending part of the positive half cycle of the power signal charges a capacitor (C3). During the descending part of the power signal the capacitor starts to discharge with a time constant which is remarkably greater than the cycle length of the power signal. The transistor is biassed by means of a transistor (Q1) so that it is conductive even at the lowest power levels.

Abstract: A radio frequency ("RF") power sensor providing RF signal power sensing with reduced dependency upon its input signal power level includes multiple series-connected diodes for detecting the power of an input RF signal and providing an output voltage representing that power. The multiple series-connected diodes couple the input node shunted by an input load resistor to the output node shunted by an output filter capacitor. Using multiple series-connected diodes results in reduced reverse bias voltages across the diodes (presented by the charged output filter capacitor), thereby increasing their junction capacitances. These increased junction capacitances, in turn, result in reduced fractional changes thereof (e.g. capacitance "modulation") over changes in the input RF signal power. This reduction in fractional capacitance changes as a function of input signal power variations, further in turn, results in reduced input signal power dependency of the sensors' impedances and sensitivities.

Abstract: A removable alternating current measuring circuit provides for measuring radio frequency currents produced in an AM transmitter-antenna system without draining any power from the system. A transformer couples the transmitter-antenna system with the current measuring circuit, which includes a first and second half wave circuits for operation during the positive and negative half cycles of alternating current. During the positive half cycle, a first diode directs current through a first load resistor and through a series combination including a second load resistor and a direct current meter. During the negative half cycle, a second diode in opposition to the first diode directs current through the second load resistor and through a series combination including the first load resistor and the current meter. Current always flows through the meter in the same direction.

Abstract: An apparatus and method are disclosed for measuring and displaying the percentage of ac voltage ripple present on a direct current input voltage. In addition, the apparatus can be set to activate alarms and trip relays when the percentage of ac voltage ripple meets or exceeds a preset value.

Abstract: A temperature compensated level detector is disclosed in which a voltage multiplying rectifier is provided for rectifying and smoothing a high-frequency input voltage to obtain a DC output, and a bias voltage generator is added to said voltage multiplying rectifier, for providing a forward bias voltage. The bias voltage generator has a temperature compensating function.

Abstract: A temperature compensated power detector utilizes a temperature compensating diode connected to an inverting input of an amplifier to enable the amplifier to substantially cancel out undesirable temperature effects caused by a power level detector diode coupled to the non-inverting input of the amplifier. As a result, the amplifier output voltage tends to remain constant over temperature in response to a fixed power level being applied to the detector. A lookup table is utilized to determine the power level corresponding to a power detector output voltage of a particular magnitude.

Abstract: Disclosed is apparatus and method for converting and displaying the total RMS and AC RMS values of a signal in a voltmeter. This conversion is accomplished in a system having a processor and a plurality of signal conversion stages. The first signal conversion stage comprises a low-pass filter to extract the DC component of the input signal followed by an analog-to-digital converter to convert the DC component into a digital value. The remaining signal conversion stages convert the AC component of the input signal to a series of smaller and smaller DC average values. Typically there are five of these AC conversion stages, each comprising a high-pass filter connected to a full-wave rectifier which is in turn connected to a low-pass filter followed by an analog-to-digital converter. The first AC stage high-pass filter is connected to the input signal and subsequent AC stage high-pass filters are connected to the output of the full-wave rectifier of the previous AC conversion stage.

Abstract: A line isolated current detector for detecting low frequency peak to peak currents on a high frequency chopped line with a first series diode and resistor detecting positive waves and a second series diode and resistor detecting negative waves. First and second capacitors across the first and second resistors, respectively, temporarily store positive and negative detected waves. A third series diode and resistor connected in parallel across the first series diode and resistor and a fourth series diode and resistor connected in parallel across the second series diode and resistor allows faster charging and slower discharging of the capacitors. This allow the capacitors to charge waveforms quick enough to use a high frequency current transformer sensing a high frequency chopped line and discharge waveform slow enough to reconstruct the low frequency waveform before high frequency chopping to allow accurate current measurements of direct current or low frequency currents using a current transformer.

Abstract: An apparatus for monitoring alternating currents and providing a signal representative of the current. The signals are rectified by a modified full wave rectrifier to provide a power source, a positive signal associated with the positive range of the current, and a positive signal associated with the negative range of the current. The two positive signals serve to preserve the polarity information associated with the current being monitored. The apparatus also provides for combining the negative signals to produce other signals useable by a microprocessor and an analog logic circuit.

Abstract: A high voltage pulse regulator which is capable of measuring and correcting voltage perturbations on the top of a high voltage square wave pulse is disclosed. The regulator uses: a rectifying diode, an oscilloscope, a variable zener diode, a variable biasing current source and pulse capacitor. The rectifying diode receives and rectifies the high voltage square wave pulse from a high voltage pulse source to produce a rectified square wave pulse. The rectified square wave pulse is received and regulated to a voltage level acceptable to the oscilloscope by the variable zener diode pulse capacitor, and current source, which are connected together in a parallel circuit and act as follows. The variable zener diode is activated by the biasing current.

Abstract: A transformerless line powdered digital AC voltmeter for selected voltage ranges is disclosed which takes a minimum of electrical power from the AC line being measured. The AC input is firstly directed to an AC/DC converter to furnish a source of DC operative voltage, the AC/DC converter possessing external electronic circuitry to assure that an adequate minimum voltage appears as its input for any selected voltage range the invention measures. The AC voltage input to be measured is first halfwave rectified, and then voltage divided and smoothed before directed to the input of an A/D converter. The A/D converter has specific external circuitry added to it to assure that the output is accurate over the range of the voltages to be measured. The output of A/D converter is directed to a liquid crystal display which visually indicates the AC voltage measured. A external electronic circuit determines the decimal point for the voltage range measured.

Abstract: A method for measuring the difference between two voltages with a time-controlled measuring cycle includes feeding two voltages with opposite polarity to one integrator, initially integrating up one of the voltages and subsequently integrating down the other of the voltages with the integrator in an integration cycle, and delivering a voltage corresponding to the mean valve of the difference between the voltage at an output at the conclusion of the integration cycle.

Abstract: DC magnetic flux bias imposed on a magnetic core of a current transformer is compensated in response to an indication of the amplitude and duration of opposite polarity secondary winding current components. In a second embodiment, the magnetic bias is compensated by responding to the integral of the secondary current. The integral of the secondary current is a measure of the magnetic core flux variations. The durations of the positive and negative flux variations are compared.

Abstract: A digital integrator for sensors which takes a time varying current or charge flow signal and converts it into a proportional voltage varying signal. The voltage varying signal is then preferably passed through an active full wave rectification subcircuit to provide an absolute value of the time varying voltage signal. The voltage signal also is analyzed by a zero crossing detector. The absolute value signal is converted into a proportional frequency varying signal which is counted either positively or negatively to produce an integral of the current flow with time. The integrator can be used with sensors such as piezoelectric crystals to indicate force on a real-time basis. The integrator is described as part of an animal hoof force detection system.

Abstract: A voltage measuring device for accurately sensing the AC load voltage at remote, distal end of a long, two-conductor cable, the measuring device comprising a parallel arrangement of an AC source and a DC voltmeter, located at the proximal, source end of the cable, and an AC load in parallel with a passive, DC producing module at the distal, load end of the cable, the passive module further comprising a passive, DC producing voltage divider, the output of which is proportional to the AC load voltage drop.

Abstract: A device for detecting voltage fluctuation including a first amplifier for amplifying an input voltage signal, a second amplifier for amplifying the same input voltage signal with a fixed delay time relatively to the first amplifier and a voltage comparator for comparing the respective amplified output voltages to produce a high-level output at the time of increase or decrease of the input voltage signal.

Abstract: A circuit testing device, including a casing having opposite ends, a single probe rigidly projecting from one end of the casing so that the casing may be manipulated to forcibly insert the probe into an electrical power socket, the casing carrying a first socket terminal, and there being a second probe connected with the socket terminal, circuitry in the casing including at least one Zener diode and at least one half wave rectifier interconnecting the single probe and the socket terminal, a presence-of-voltage circuit in the casing and electrically connected with the single probe, the circuit including a presence of voltage indicator and rectifier and amplifier elements electrically connected between the single probe and the indicator, the rectifier element including a rectifier bridge having two terminals connected across the Zener diode, there also being a voltage level indicating meter connected in series with such circuitry.

Abstract: An electric field sensitive probe capable of measuring both CW and pulsed signals with consistent efficiency using a diode detector connected to a dipole antenna in which a shunt capacitor is connected in parallel with the dipole and one or more resistive elements are connected in series between the diode and the dipole.

Abstract: A current sensor assures the detection of a current flowing through a welder conductor without requiring a particular power source, and indicates the current state with the aid of a lamp. In one embodiment, a welder conductor penetrates a toroidal core across which connects a slider resistor whose sliding arm connects through a rectifier circuit, and a parallel circuit of a capacitor and a resistor, to a lamp. A second embodiment imterposed between the parallel circuit and lamp wherein a series circuit of a second resistor and a Zener diode, and a transistor base is connected to a connection point between the second resistor and a Zener diode, and the emitter-collector circuit of which transistor drives the lamp. A third embodiment adds a further series circuit of another lamp and resistor across the parallel circuit and across the series circuit of the second resistor and the Zener diode.

Abstract: An indicator apparatus has multiple stages to effectively handle data processing, particularly raw data from a mechanical load cell, such as those used to monitor loads in the mechanical workings of a torque arm reducer. Processing of such raw data is split into parallel operations relating to both signal level and signal polarity functions. This multi-staged approach enables increased precision as to both functions due to tailoring of the data inputs to different stages. Use of staged circuitry to effect the separated functions also readily permits the presence of an unobtrusive monitor level signal output. Combined with other features, a limit detector and alarm permits accurate provision of both a stable response to low frequency steady state mechanical data and to fast-acting high frequency transient/dynamic data contained therein. Indicated polarity changes signify alternating tension and compression in the mechanical couplings of a load cell.

Abstract: The invention consists in using current transformers incorporated in the electronic relays of a switchboard protective device and in connecting thereto current measurement indicators located on the front face of the switchboard.

Abstract: An ammeter apparatus and method of taking current reading includes current inputs receiving a signal from a current source through a suitable gate. A conversion circuit having a preamplifier and an amplifier, in inverted configuration, produce a signed voltage proportional to the current signal. The signed voltage is passed, to both a rectifier and a polarity indicator through another gate. A comparator switches the polarity indicator gate and a third gate upon receipt of a threshold value rectified voltage from the rectifier. The third gate interconnects the rectifier and a charge-retaining element, and a meter outputs a display corresponding to the charge thereon. A fourth gate connects the charge-retaining element to ground in order to discharge the retained charge. A timing circuit with a manual override operates the input gate and the fourth gate, and a timed power supply provides operating voltage for the circuit.

Abstract: An electric field probe array including several dipole probes, each including a diode connected between two conductors with the diodes being collectively connected to at least two probe terminals. Also disclosed is a system for heating a target with electromagnetic radiation that includes a central control unit, a source coupled to the control unit with the source generating the electromagnetic energy at a frequency and power in response to the control unit, a radiation apparatus coupled to the source for transferring the electromagnetic energy from the source to the target and input circuitry connected to the control unit for indicating the status of the target whereby the operation of the system is controlled by the control unit as a function of the target's status.

Abstract: A unique diode sensor adapted for responding with pre-established sensitivity over a range of relatively low frequencies. A diode is connected to a dipole antenna having both conductive and resistive portions. Lumped impedances are connected in parallel with the diode and the values of these impedances are selected in coordination with the characteristics of the diode and antenna to control the sensitivity of the sensor as a function of the frequency of the illuminating energy.

Abstract: An analog-digital conversion circuit apparatus connectable to a microcomputer for measuring electric voltage and current of a vibrator of an ultrasonic wave oscillator is disclosed. An analog high-frequency wave voltage value signal and an analog high-frequency wave current value signal acquired from a vibration system are alternately input to a conversion-transmission section. A digital high-frequency wave voltage value signal and a digital high-frequency wave current value signal, which have been converted in the conversion-transmission section, are transmitted to the microcomputer for various uses connected with the electric voltage and current of the vibrator of the ultrasonic wave oscillator.

Abstract: An electromagnetic field detector adapted to display potential hazard to humans and other animals arising from illuminating electromagnetic energy over the frequency range determined to be hazardous by the American National Standards Institute; the detector being designed with various sensing means to create a sensitivity vs. frequency response that is the inverse of the A.N.S.I. protection guides.

Abstract: An RF wattmeter is disclosed of the type using an "insertion-type" pick-up element to produce a voltage wave signal corresponding to the measured power in the coaxial transmission line. The induction loop in the pick-up element is connected to a principal detector, and a secondary detector is connected in opposition to the principal detector. Both detectors are located in close proximity to each other and are subject to the same thermal environment. A sine wave generator supplies a wave signal to the secondary detector in opposition to the wave signal supplied to the principal detector from the inductive loop. The d.c. portion of the resulting signal representing the difference between the opposed signals is integrated, and the integrated output is used as the amplitude in the generated sine wave. When the circuit is in balance, the integrated output matches the amplitude of the inductive wave form and can be used as an output indicating measured power in the coaxial transmission line.

Abstract: In a DC current detector, a current to be detected is applied to a current detecting resistor connected in series with a first diode, a voltage across the current detecting resistor is amplified by a transistor and the detected voltage is output from a collector resistor connected to the collector of the transistor. The voltage across the current detecting resistor is provided across the emitter and base of the transistor via an emitter resistor, and a second diode. A resistor the resistance value of which is selected so that the forward voltage of the second diode and the base-emitter voltage of the transistor may become equal to each other, is connected to the base of the transistor. The current detection accuracy is improved.

Abstract: This portable microwave radiation monitor utilizes an antenna formed in a dual Archimedean spiral. The power density of the electric field is indicated on a meter coupled to diode means connected across the inner terminals of the antenna by inductance means selected to resonate with the variable capacitance of the diode, substantially at the frequency of the field being monitored.

Abstract: This portable microwave radiation monitor utilizes an antenna formed in a dual Archimedean spiral. The ellipse ratio of the spiral is minimized by selective placement of resistive means over a portion of the antenna and the power density of the electric field is indicated on a meter connected via diode means to the inner terminals of the antenna.

Abstract: A self-powered ammeter is disclosed. A metering circuit receives an a-c current to be tested and then generates a d-c voltage whose magnitude is proportional thereto. A display circuit receives the d-c metered voltage and provides a visual indication of the magnitude of the measured current. The current to be measured also drives a current transformer which, in turn, has an output burden circuit which produces a regulated power supply for the metering and display circuit components.

Abstract: A radiation detector for free space microwave radiation uses thin film resistive strips, having an equivalent surface resistivity that is large compared to the characteristic impedance of free space, and diode circuits in series with the strips for deriving d-c signals monitoring the radiation intensity over a broad frequency range. In part of that range, the strips operate like a short dipole antenna. The diode circuits are constructed to operate with a uniform response over the entire frequency range.

Abstract: A non-contact device for monitoring electrical pulse signals includes a sensing means responsive to variation with time of the electromagnetic field produced by the monitored pulse signals, an amplifier connected to the sensing means, a rectifier connected to the amplifier via a network including an aperiodic circuit and a differentiating circuit connected in series, and an indicator unit connected to the rectifier.

Abstract: A monitor for a polyphase power line continuously compares the voltage on each phase of the power line with reference voltages that are selected percentages above and below the average of the power line voltages to detect voltage unbalance and with fixed voltages to detect high or low voltage conditions. The monitor is also responsive to phase sequence.

Abstract: Power measuring apparatus for electric appliances including interconnected male and female connectors for attachment to a source of power and to an appliance to be measured, a transformer having a primary winding in series with one of the conductors interconnecting the connectors, a potentiometer having a resistance element connected with the secondary winding on said transformer and a movable contactor, and an indicator connected between the contactor and one end of the resistance element, the potentiometer being calibrated in terms of cost per kilowatt-hour and the indicator being calibrated in terms of cost per hour.