Abstract: A monitoring system that is configured to monitor a property is disclosed. The monitoring system includes a sensor that is configured to generate sensor data that reflects an environmental condition of the property and an electrical monitoring device coupled to an electrical cord that provides power to an electrical device located at the property. The electrical monitoring device is configured to generate electrical data that reflects electricity that flows through the electrical cord. The monitoring system includes a monitor control unit that is configured to: receive, from the sensor, the sensor data; receive, from the electrical monitoring device, the electrical data; and analyze the sensor data and the electrical data. The monitor control unit is configured to: based on analyzing the sensor data and the electrical data, determine a status of the electrical device; and based on the status of the electrical device, perform a monitoring system action.

Abstract: An apparatus and method of removing common mode noise in the case of measuring a biosignal using a capacitive coupling active electrode (CCE) is provided. A frequency band of a common mode signal may interact with a shield voltage and thus, a frequency band of a biosignal may be compensated for.

Abstract: A method for monitoring the function of a sensor module including sensor which generates a measurement signal for a physical quantity to be determined and applies the measurement signal to an output terminal in an unchanged form or in processed form. In addition, a test signal is generated whose spectrum lies outside the spectrum of the measurement signal. The test signal is supplied at a place in the sensor from which it reaches the output terminal in unchanged form or in processed form only in the case of a functional sensor. An output signal present at the output terminal is compared with the test signal and a diagnosis signal is generated, which indicates whether the test signal is present at the output terminal. The test signal is filtered out of the output signal and the remaining signal is applied as the measurement signal at an output of the sensor module.

Abstract: A safe powerline communications instrumentation front end device including a voltage input for receiving a line voltage from a powerline, a voltage reducer for reducing the voltage of the line voltage, a filtering system for extracting a Power Line Communications (PLC) signal from the line voltage, and an analog output for outputting the PLC signal as an analog signal for communications test equipment

Abstract: An analyte sensor apparatus and a corresponding fluid medium, the analyte sensor apparatus comprising a sensing element, the external surface of which comprises a membrane to inhibit exposure of the sensing element; the corresponding fluid medium comprising a receptor species and an activatable species, the receptor species for interacting with an analyte to activate the activatable species, activation of the activated species causing increased porosity of the membrane of an in-contact analyte sensor apparatus to correspondingly increase exposure of the sensing element to allow for production of a detectable electrical signal which can be used to sense the presence of the analyte.

Abstract: Electrical current sensor comprising a measuring circuit (6) and an inductor (4) for measuring a primary current IP flowing in a primary conductor (2), the inductor comprising a saturable magnetic core (10) made of a highly permeable magnetic material and a secondary coil (12) for carrying an alternating excitation i configured to alternatingly saturate the magnetic core, the coil being connected to the measuring circuit. The measuring circuit is configured to supply a positive or negative voltage to the inductor, to switch off the voltage when a condition signalling saturation is reached, to measure the time to saturation t1 in one direction and the time to saturation t2 in the other direction of the magnetic core and determine therefrom a value of the primary current for small current amplitudes, the measuring circuit being further configured for evaluating the average value of the excitation current i and determining therefrom the value of the primary current for large currents.

Abstract: Techniques for calculating a real power delivered to a transmit load of a transceiver. In an aspect, two distinct voltages are sampled from a matching network coupling the transmit load to an amplifier output. The voltages are coupled by configurable coupling elements to the down-conversion mixers of the transceiver, and are subsequently converted to digital form for processing by a baseband processor. The baseband processor may calculate a coefficient relating the calculated real power to an actual power delivered to the load. The coefficient may be stored and subsequently applied to a transmit element during normal signal transmission by the transceiver. Note the coupling elements may be configured to decouple the sampled voltages from the down-conversion mixers during normal signal reception by the transceiver, thus avoiding unnecessary loading on the receive signal path.

Abstract: The invention presents a method for determining the copper concentration of the substrate using the photoconductivity method in a new manner, the method comprising steps in which the photoconductivity property of the substrate is measured for a first time by an arrangement, the surface of the substrate is illuminated by illuminating means emitting photon radiation, the photoconductivity property of the substrate is measured for a second time by an arrangement, and the copper concentration of the substrate is determined from the change between the first and second time of measurement on the basis of the illumination. The invention also presents an arrangement and a software product for determining the copper concentration.

Abstract: Power supply device and an image forming apparatus having the power supply device are provided. The power supply device includes an input unit to input alternating current (AC) power, a converter to convert the input AC power to direct current (DC) power having a preset level and to output the DC power, and a sensor to be connected to the input unit in parallel and to sense whether the AC power has been input. The sensor includes a transformer to receive the AC power and to output a sensing signal having a level reduced more than a level of the AC power, and a resistor unit connected to the transformer in series so that a current of the AC power input into the transformer is lower than or equal to a preset current.

Abstract: A system and device for measuring voltage in a conductor having a voltage provides a first electrode surrounding and spaced from the conductor, and a second electrode surrounding and spaced from both the conductor and the first electrode such that there is no contact between the conductor and the electrodes or between the first and second electrodes. The first electrode is connected to a first input of a differential amplifier circuit and the second electrode is connected to the other input of the differential amplifier circuit. The output of the differential amplifier circuit provides a voltage signal in proportion to the voltage of the conductor, thus providing a non-contact means for measuring the voltage of a conductor without requiring a connection to ground while simultaneously providing a high level of rejection of external interference.

Abstract: A bidirectional voltage differentiator circuit comprises start-up circuitry, sensing circuitry, and output circuitry coupled to logic circuitry. The start-up circuitry acts to start-up the sensing circuitry when the circuit is powered on, and accelerates the response of the sensing circuitry thereafter. The sensing circuitry senses variation in an input voltage applied to an input node. Responsive to the voltage variation sensed by the sensing circuitry, the output circuitry produces a state change at a first or second output node. The logic circuitry receives the states of the output nodes and produces a logic output signal to indicate the occurrence of the variation sensed in the input voltage. The voltage sensing circuit is operable to sense variation of the input voltage regardless of whether the voltage is rising or falling and without regard to the DC value of the input voltage.

Abstract: Electrical currents are detected and analyzed across structural members in a structural joint, such as a fastener of a vehicle. In some aspects, printed circuit boards etched with Rogowski coil circuits are inserted proximate the structural members in the structural joint. The Rogowski coil circuits may detect an electrical current as it flows through the structural joint. An integrator may integrate a transient current to generate an output signal, such as when the vehicle is subjected to an electrical charge. The output signal may be transmitted to an Integrated Vehicle Health Management (IVHM) system for analysis. In various aspects, the IVHM system may enable recording and reporting of various aspects of the current to enable maintenance, inspection, or real time/near real time health assessment of the vehicle.

Abstract: A circuit for measuring current drawn by a self-powered electronic protection device. The circuit monitors current in a polyphase alternating current (AC) power source by measuring current in a rectified secondary winding of a current transformer coupled to a phase current of the power source. The measurement circuit includes a measurement burden connected between the cathode of the current transformer rectifier and a switch. Closing the switch references the voltage drop across the measurement burden to a reference potential. A controller closes the switch while receiving measurements of the voltage drop. Because the voltage drop is referenced to a reference potential, it can be analyzed in a controller to detect a fault condition without being conditioned with an inverting amplifier or a difference amplifier.

Abstract: The invention concerns a high frequency non-linear measurement system for analysing the behaviour of a high frequency device, for example a device for use in a high power, high frequency amplifier, such as an amplifier for use in a mobile telephone network or other telecommunications-related base-station. An embodiment of the invention provides a high frequency non-linear measurement system including one or more multiplexer circuits. Each multiplexer circuit comprises a first signal-combining circuit and a second signal-combining circuit. Each signal-combining circuit comprises a pair of directional couplers connected via a pair of signal filters arranged in parallel.

Abstract: According to one embodiment, a voltage measuring device that measures an input voltage signal includes a divider, a filter, an adder, and an analog-to-digital converter. The divider divides the input voltage signal into a first signal and a second signal. The filter filters the first signal and attenuates a direct current component of the first signal less than a predetermined frequency component of an alternating current component of the first signal. The adder adds an output signal of the filter to the second signal. The analog-to-digital converter converts an output signal of the adder into a digital signal. The divider adjusts the amplitude of at least one of the first signal and the second signal such that the level of a direct current component of the output signal of the adder is in the input range of the analog-to-digital converter.

Abstract: A residual current detection device comprising a plurality of resistive shunts for connection in respective ones of a plurality of lines though which current can flow to and from a load, and detector means sensitive to the voltage developed across each of the shunts to detect any imbalance between the currents flowing though the shunts.

Abstract: Monitoring method and monitoring device for a filter mounted upstream from a electric circuit which has at least one filter component with a filter characteristic. With these method and device, a time characteristic of at least one filter current flowing in the filter and a time characteristic of at least one filter voltage present in the filter are recorded during the operation of the electric circuit. At least one filter characteristic is then determined from the time characteristics.

Abstract: An apparatus and method for measuring electric current. The apparatus includes a conductive shunt for developing a voltage drop in response to current flow through the shunt, a temperature sensor for sensing the temperature of the shunt, and an amplifier for amplifying the voltage drop across the shunt. The voltage drop developed by the shunt has a known dependence upon the temperature of the shunt. The amplifier has an output for producing a current signal indicative of current flow through the shunt and has a gain dependent upon the temperature of the shunt, to compensate the current signal for changes in the voltage drop across the shunt due to the known dependence upon temperature of the voltage drop developed by the shunt.

Abstract: This invention is an inexpensive probe apparatus operating at high precision that can be used for both low-frequency and high-frequency measurements. A line with a first and second conductor is extended from a probe connected to a circuit component. A low-frequency or high-frequency device is alternately connected to the line. A third common conductor runs parallel to the aforementioned line and a resistor and capacitor is connected between the probe end of the aforementioned second conductor and the aforementioned common conductor.

Abstract: A hand-held detector for determining whether the exposure to electromagnetic fields resulting from electric power lines, faulty wiring, and electrical and electronic appliances is within acceptable limits. The device includes a shielded pickup coil, a filter circuit having a transfer function which provides a distinct response in two frequency bands, a summing circuit which provides a voltage indicative of the detected levels of electromagnetic flux density in the two frequency bands, and a display circuit, to provide a visual indication of the detected energy level. The filtering circuit preferably includes a first, extremely low frequency (ELF) amplifier having an upper cutoff frequency of approximately 2 kHz, and a second, very low frequency (VLF) amplifier having a lower cutoff at approximately 6 kHz.

Abstract: The invention discloses a magnetic field radiation monitor which comprises at least one sense coil adapted to sense magnetic flux from the electromagnetic field to be measured for both ELF and VLF type of fields. The sense coil is coupled to a detection circuit wherein an EMF generated in the sense coil will be amplified and frequency compensated in the circuit to give an extremely flat frequency response allowing accurate detection of complex magnetic fields. The circuit consists of an ELF and VLF stage, both selectively coupled to the sense coil and incorporated into the circuit by a user activated switch. The output of either the ELF or VLF stages is further processed and the output is provided to a display to indicate the magnetic field strength measured. The magnetic field radiation monitor may be calibrated to yield a true RMS measuring platform using a RMS detector circuit which will give an accurate indication of magnetic energy content for complex waveforms.

Abstract: In this digital signal measurement apparatus, an approach is employed to deliver a measurement signal from a measurement signal generator to a measured circuit to transform the signal on the time base through the measured circuit to a signal on the frequency base by a frequency base transform circuit and to further obtain a signal on the time base by a time base transform circuit. Thus, a difference between the signal on the time base through the measured circuit and the signal on the time base from the time base transform circuit is employed. Thus, for example, even if the measured circuit is a linear system, a measured result in the digital region and a result of the analog measurement can be in correspondence with each other. Accordingly, gain correction of a measurement signal is unnecessary, thus making it possible to prevent an increase in an error of a measured result of S/N.

Abstract: A heterodyning lock-in amplifier in which the reference signal is shifted up in frequency (as in prior art designs), but then shifted back down in frequency prior to mixing with the input signal.

Abstract: A portable instrument for locating and measuring harmonic distortion in a conductor. The instrument permits voltage and current harmonics to be easily read while the load is changing. Thus, the instrument may provide a great deal of insight as to the source of problem causing harmonics.

Abstract: A device for noise peak suppression during a potentiometer evaluation has a potentiometer located between a reference voltage and mass and having a slider with a slider output, a control device adapted to receive a signal from the slider output of the potentiometer, and an amplifying unit located between the potentiometer and the control device so that a signal picked up from the slider output is amplified in the amplfying unit before being supplied to the control device.

Abstract: A meter drive inhibit circuit is provided whereby an erroneous jump of the meter pointer upon system power-up or subsequent microcomputer reset operation is inhibited. A pulse generator is utilized to produce output pulses relating to the rate of rotation of a drive shaft in a typical tachometer application. Such output pulses are provided to a meter drive circuit which in turn provides an output to an electromechanical meter. Such electromechanical meter will display an output related to the time average value of pulses input to the meter drive circuit. An inhibit circuit stage is connected to the meter drive. A microcomputer is utilized to sense the power-up condition of the meter circuit and activate the inhibit stage. When activated, the inhibit stage will prohibit the meter drive from providing an output to the meter and thereby prevent the erroneous jump of the meter pointer upon system power-up.

Abstract: A current transformer and copper sulfate water resistor are combined to provide a probe capable of measuring very fast, high voltage pulses. The resistor is connected in series with the primary winding of the current transformer and consists of an elongated plastic tube filled with an aqueous solution of copper sulfate. The series arrangement of resistor and current transformer primary winding is applied across the source of voltage to be measured and the current transformer secondary winding output is a function of the measured voltage. The current transformer secondary output is applied to and displayed on an oscilloscope.

Abstract: A method and device for testing inductive pulse generators of the type used as wheel-rpm feedback transducers in anti-wheel-lock action in automotive braking systems. Within a portion of the range of frequencies at which such inductive pulse generator produces output voltage pulses, the amplitude and frequency of such pulses vary approximately in proportion to each other. In accordance with the present invention, a quality characterization signal is derived which varies similarly to the ratio of pulse amplitude and pulse frequency. Thus, within such frequency range, or equivalently within the corresponding range of wheel rotation speed in the context specified above, the value of the quality characterization signal will be independent of the frequency or wheel rpm at which the test happens to be performed.

Abstract: A probe adapted for selectively measuring either symmetrical or asymmetrical interference voltages or interference voltages between terminal and ground and utilizing first and second transformers having interconnected primary windings and tightly magnetically coupled secondary windings connectible with the interference measuring set for optionally measuring either symmetrical or asymmetrical voltages or voltages against ground, is disclosed. When measuring a balanced (symmetrical) voltage the terminals of the first transformer primary winding are coupled to the opposite poles of the specimen under test. When measuring an unbalanced (asymmetrical) voltage or a voltage with respect to ground, both terminals of the first transformer winding are connected in common to the pole of the specimen under test. In an cases a single ground terminal of the probe is connected to the ground of the specimen under test.

Abstract: Apparatus for measuring a high voltage in an ignition circuit, in which voltage dividing means has a first arm for connection to a point of measurement in said circuit and a second arm connected to a rectifying means. The output of the rectifying means is connected to means for matching impedance at the rectifying means to a direct current voltage display means connected to the output of the impedance matching means such that a displayed voltage is related to the high voltage in the ignition circuit. Low voltage measuring circuitry is also present which is connectable directly to the display means without the use of an impedance matching circuit.

Abstract: A capacitor divider type high alternating voltage monitoring apparatus incorporating a filter with a switchable gain/frequency characteristic for removing the effect of d.c. voltage error arising from trapped charge on the capacitor divider.

Abstract: To measure the level of test signals over a frequency range of variable bandwidth B, bounded by a lower frequency f' and an upper frequency f", these signals are heterodyned with a variable modulating frequency to produce a frequency spectrum encompassing the pass band of an intermediate-frequency filter of fixed bandwidth b.ltoreq.B, centered on a frequency f.sub.c. By periodically shifting the modulating frequency between a minimum value of f'-f.sub.c +(b/2) and a maximum value of f"-f.sub.c -(b/2), either continuously or in steps, the frequency range of bandwidth B is scanned by a window of bandwidth b transposed to the pass band of the filter as the midfrequency f.sub.m of the window varies in a sweep cycle between f'+b/2 and f"-b/2. The signal level in the output of the filter, integrated over the sweep cycle, is weighted with a corrective factor B/b.

Abstract: An electrical circuit for digitally displaying an input electrical signal to minimize fluctuations in the output and maximize the speed of response to changes in the input signal whereby the input signal is applied to a first low pass filter and a second low pass filter having both a lower threshold frequency and a slower response time to changes in the input signal than the first filter. The outputs of the two filters are applied to a differential amplifier to produce a differential signal which is applied via a pair of serially and oppositely connected Zener diodes to the output of the second filter, which is also connected to the digital display, to cause rapid response to signal changes. The frequency of a unijunction oscillator is also controlled by the differential signal to increase the measuring rate of the digital display whenever the input signal charges by more than a predetermined value.

Abstract: The noisy amplified signal from a photoelectric device is passed through an electronic low-pass filter before having its direct current component read on a meter. The cut-off frequency of the low-pass filter is adjusted in known manner by rotation of a control knob, so as to suitably match the cut-off frequency to the noisiness of the signal with a view towards speeding up the stabilization of the meter reading. To overcome the sluggishness of the system, the same control knob is briefly pushed, thereby overriding the low pass control. The method of using the system to speed up meter reading is described.

Abstract: The logic circuit tester probe system described herein incorporates noise filter and data discrimination capability by comparing the duration of pulses received with the duration of the output of a one-shot. The probe system also incorporates misprobe detection capability which alerts the user that his probe is not making electrical contact with the circuit node under test whenever the input of the probe assumes the magnitude of a reference voltage rather than the magnitude of the voltage at the circuit node.

Abstract: A spectrometer is scanned across a desired frequency range. A selective filter is automatically varied to alter its characteristics according to the spectrometer's scanning rate by a single control voltage; to assure that the filter's characteristics are optimum for both fast and slow scanning rates.This invention relates to spectrometers and more particularly to apparatus for enabling automatic tracking of filter characteristics during the scanning of a spectrometer.