Abstract: The present invention provides a system for detecting and analyzing at least one of an electric field and an electromagnetic field. The system includes a micro/nanomechanical oscillator which oscillates in the presence of at least one of the electric field and the electromagnetic field. The micro/nanomechanical oscillator includes a dense array of cantilevers mounted to a substrate. A charge localized on a tip of each cantilever interacts with and oscillates in the presence of the electric and/or electromagnetic field. The system further includes a subsystem for recording the movement of the cantilever to extract information from the electric and/or electromagnetic field. The system further includes a means of adjusting a stiffness of the cantilever to heterodyne tune an operating frequency of the system over a frequency range.

Abstract: An optical fiber for a sensor that can measure a current or a voltage precisely is provided. The optical fiber for the sensor 10 comprises: an FBG 12 wherein a refractive index of a core changes periodically; a metal layer 13 for sheathing the FBG 12; and a pair of electrodes 14 and 15 provided at the metal layer 13. The electrodes 14 and 15 are connected to an object to be measured in desired positions. Current flowing through the metal layer 13 is calculated based on variation in Bragg wavelength of the FBG 12.

Abstract: An electric measuring apparatus is constructed in such a way as to include a signal processing circuit equipped with at least a polarized light separating unit, Faraday rotators, a light source, a photoelectric conversion element, and optical fibers for a sensor. The optical fibers for the sensor are placed around the periphery of an electrical conductor through which electric current to be measured flows. Furthermore, the rotation angle of each Faraday rotator at the time when the magnetism of each Faraday rotator is saturated is set to 22.5°+?° at a temperature of 23° C., thereby changing the rotation angle of each Faraday rotator by ?° from 22.5°.

Abstract: In the field of the counting of objects, a use is provided of a photosensitive assembly comprising at least one photodiode or one photoresistor, and a source of uniform illumination for illuminating the assembly, the establishment of a reference current supplied by the photosensitive assembly for an illuminated region of this assembly corresponding to a given fraction of the surface of the assembly, the disposition of objects to be counted against the photosensitive assembly, the illumination of the assembly by the source, the objects masking a part of the surface of the assembly, measurement of the current supplied by the assembly, and determination of a ratio between measured current and reference current to deduce the proportion between the surface area of photosensitive element illuminated and the surface area masked by the objects disposed. From this ratio, information on the number of objects disposed on the photosensitive assembly is extracted.

Abstract: Provided is a technique for mass-producing a conductor to which is fixed a current detection head that detects the value of current flowing in the conductor, and in which the relationship between the detection value and the current value is stabilized. The head comprises a lens, a magneto-optical element, a conductor, and a fixing member, and the lens, the magneto-optical element, and the conductor are respectively fixed to the fixing member. An optical system is formed using the current detection head such that light is guided through the lens to the magneto-optical element, and light affected by a magneto-optical effect due to the magneto-optical element is guided to the lens. All of the members contributing to current detection are fixed to the fixing member, and therefore the relative positional relationships of all the members contributing to current detection are uniquely determined, enabling conductors with little variation in current detection characteristics to be mass-produced.

Abstract: A method of detecting irregular high current flow within an integrated circuit (IC) device is described. The method comprises obtaining infrared (IR) emission information for the IC device, identifying at least one functional component within the IC device comprising a high current flow, based at least partly on the obtained IR emission information, obtaining IR emission information for at least one reference component within the IC device, and determining whether the high current flow of the at least one functional component comprises an irregular high current flow based at least partly on a comparison of respective IR emission information for the at least one functional component and the at least one reference component.

Abstract: A device for attaching to an electric power line conductor includes a housing with an opening for accepting the power line conductor. The housing is configured to be grounded to the power line conductor. At least one magnetic core is configured to surround the power line conductor and power a power supply electronics module. A solar sensing element is configured to be mounted horizontally on the housing.

Abstract: An installation base is secured to part of outer peripheral surface of cylindrical container 1 which has electric conductor 2 arranged thereinside, and a case which stores a Faraday-effect element is detachably secured to the installation base. Faraday-effect element 10 having two optical fibers 24A, 24B of prescribed dimensions, to provide first and second optical paths 11A, 11B maintained in parallel with a predetermined interval therebetween and placed so as to intersect axial direction of electric conductor 2, and having mirror 12 which reflects linearly polarized light at one end surface of each optical fiber. Linearly polarized light from the same light source injected into each of the optical paths 11A, 11B, and current flowing in electric conductor 2 is measured base on the Faraday rotation angle of the linearly polarized light reflected and returned from mirror 12.

Abstract: A master-slave current sensor system for measuring, for example, differential current on a transmission line is described. The slave current sensor can be periodically recalibrated (or have a compensation value re-calculated) based on the master sensor's average output, and the slave sensor can be unpowered and remote from an electronics box which receives its measurements. Health monitoring and fault location can also be performed using the master-slave optical current sensor system, optionally in conjunction with one or more voltage sensors.

Abstract: In accordance with an embodiment, an inspection apparatus includes an electron beam applying unit, a voltage applying unit, a substantially flat component with a lattice pattern, and a first detector. The electron beam applying unit generates an electron beam and applies the electron beam to a sample at a first voltage. The voltage applying unit applies a second voltage to the sample. The polarity of the second voltage is opposite to that of the first voltage. The absolute value of the second voltage exceeds the absolute value of the first voltage. The component is provided at a position where the electron beam specularly reflected by the second voltage before reaching the sample is focused. The first detector detects a secondary electron generated from the component which the specularly reflected electron beam has entered and outputs a first signal.

Abstract: A system is provided. The system includes a fiber optic current sensor, and a fiber optic current transducer optically coupled to the fiber optic current sensor and configured to receive polarized light from the fiber optic current sensor, generate an electrical signal from the polarized light, and isolate a direct current (DC) component of the electrical signal. The system further includes a monitoring circuit communicatively coupled to the fiber optic current transducer and configured to receive the DC component from the fiber optic current transducer, and generate an output signal based on the DC component, wherein the output signal is indicative of an operational state of the fiber optic current sensor and the fiber optic current transducer.

Abstract: A method of measuring fluctuations in electric fields is disclosed, the method comprising the step of: placing a Liquid Crystal Device in communication with the electric field, the device having disparate orthogonal polarization sensitivity to an external electric field; utilising an optical probe beam having a known polarization state to interrogate the liquid crystal of the liquid crystal device to produce a response beam; and analyzing the polarization state of the response beam to provide an indicator of the corresponding fluctuations in the electric field.

Abstract: Systems and methods related to optical current and voltage sensors and, more particularly, to filters for use in such sensors. A fiber optic current sensor comprising: a light source; a polarization beam splitter connected to said light source having a reciprocal port and a non-reciprocal port; a Faraday rotator connected to said polarization beam splitter; a first quarter-wave plate connected to said Faraday rotator; a polarization maintaining fiber connected to said first quarter-wave plate; a second quarter-wave plate connected to said polarization maintaining fiber; a sensing fiber connected to said second quarter-wave plate; a detector connected to said polarization beam splitter via said non-reciprocal port and having an output; and an adaptive filter for filtering said output.

Abstract: An optical receiver includes a light reception element for receiving an optical signal, a bias voltage supply/monitoring circuit for supplying a bias voltage to the light reception element and generating a monitoring voltage indicating magnitude of an output current of the light reception element, and a constant current source. The bias voltage supply/monitoring circuit is supplied with a remaining current obtained by subtracting the output current of the light reception element from an output current of the constant current source. The bias voltage supply/monitoring circuit converts the remaining current to the monitoring voltage.

Abstract: System and method for implementing a Vector Network Power Meter (VNPM) as a new class of electronic test instrument that uses a novel topology based upon a reflectometer to combine the functionality of a Power Meter with that of a Vector Network Analyzer (VNA). The VNPM overcomes application limitations of the two existing classes of test instruments, including parallel and simultaneous measurement capability, in-circuit operation, and improved accuracy and repeatability by eliminating the calibration of interconnecting cabling. Also provided are alternate implementations of a correlator for the reflectometer which reduce the size and complexity of the correlator while extending its frequency range without limit.

Abstract: A sensor apparatus for measuring a plasma process parameter for processing a workpiece. The sensor apparatus includes a base, an information processor supported on or in the base, and at least one sensor supported on or in the base. The at least one sensor includes at least one sensing element configured for measuring an electrical property of a plasma and may include a transducer coupled to the at least one sensing element. The transducer can be configured to receive a signal from the sensing element and convert the signal into a second signal for input to the information processor.

Abstract: An apparatus is provided for highly accelerated life testing (HALT) of multi-junction solar cells according to a method that utilizes a high vacuum chamber, as well as lenses and windows transparent to broad spectrum solar radiation from typically a single source to house packaged solar chips and temperature monitoring and control means during testing, thereby allowing substantially greater control of environmental variables such as temperature, atmospheric composition, and light spectrum than is currently available.

Abstract: A system and method for fiber magneto-optic detection are provided, which belongs to the optical application field. The system comprises: a reference device (300) for generating a reference magnetic field signal with known amplitude and shape at a measurement point; a magneto-optic probe (100) for detecting a magnetic field signal of the measuring point, converting the magnetic field signal into an optical signal, and transmitting to a power supply and signal processing module (400) the optical signal sent by the magneto-optic probe; the power supply and signal processing module (400) for transmitting laser light, and converting the optical signal into an electrical signal after receiving it, and demodulating and analyzing the electric signal to acquire the magnetic field information and/or the current information of the measuring point.

Abstract: A determination circuit for measuring a current is reset each time the integration value of the current exceeds a threshold until expiration of a predefined maximum integration time. This increases the accuracy of integrating a current and also increases the dynamic range of currents that can be integrated. To further increase the dynamic range of currents, the determination circuit may further include circuits having different gain factors.

Abstract: An defect detection system includes an exoemission sensor having a conductive layer and an insulating layer. The exoemission sensor is mountable to a material of interest and configured to receive exoemissions from the material while in an atmosphere. The exoemission sensor outputs a signal based upon the received emissions. An analysis device is configured to receive the signal from the exoemission sensor and determine whether a defect is present in the material based upon the signal.

Abstract: A measuring method and device for characterizing a semiconductor component (1) having a pn junction and a measuring surface, which has a contacting subarea, covered by a metallization. The method including: A. Planar application of electromagnetic excitation radiation onto the measuring area of the semiconductor component (1) for separating charge carrier pairs in the semiconductor component (1), and B. spatially resolved measurement of electromagnetic radiation originating from the semiconductor component (1) using a detection unit. In one step A, a predetermined excitation subarea of the measuring surface has a predetermined intensity of the excitation radiation and at least one sink subarea of the measuring surface has an intensity of the excitation radiation which is less than the intensity applied to the excitation subarea. The excitation and sink subareas are disposed on opposite sides of said contacting subarea and adjoin it and/or entirely or partially overlap it.

Abstract: A laser protective wall element for a housing in laser machining stations with which increased protection, in particular for the eyes of living beings, can be achieved. In a laser protective wall element for a housing at laser machining stations, an intermediate layer is present which has hot conductor properties. The intermediate layer can be formed between electrically conductive plate-like elements, an electrically conductive plate-like element and an electrically conductive coating or also two electrically conductive layers or can be arranged there. The electrically conductive plate-like elements, the coating and/or the layers are connected to an electrical voltage source as well as a measuring instrument which detects electrical current, electrical resistance and/or electrical capacity and whose measured signal change can be used for the condition monitoring of the laser protective wall element.

Abstract: A polarizing optical system (15, 16) is disposed perpendicular to an optical axis of incoming light from a light source (12), having the optical axis (12) as a center axis, and configured for polarization of incoming light to a prescribed reference state, an electro-optical device (17) is disposed perpendicular to the optical axis, having the optical axis as a center axis, and adapted, as a voltage to be measured is imposed thereon, to respond to the imposed voltage by polarizing light polarized by the polarizing optical system (15, 16), and an analyzer (18) is disposed perpendicular to the optical axis, having the optical axis as a center axis, and adapted for detection of light polarized by the electro-optical device (17), to irradiate a detector (21) configured for conversion of incoming light into an electric signal.

Abstract: In a plasma reactor having pulsed RF plasma power sources, measurements by RF sensors of nulls attributable to pulse duty cycles are replaced by non-zero measurements synthesized from prior non-zero measurements, to prevent feedback control system instabilities.

Abstract: A method for conditioning a photovoltaic module for testing includes setting an effective irradiance of a continuous light source at a target plane, configuring a test photovoltaic module to operate at a substantially maximum power point configuration, positioning the test photovoltaic module adjacent to the target plane, and configuring the test photovoltaic module for testing by removing the light source, cooling the test module to a testing temperature, and reversing the substantially maximum power point configuration.

Abstract: A handheld fiber optic current and voltage monitor for applications in high voltage environment. A light source generates constant optical signal that is split by a fiber optic splitter into two paths. One path feeds a DMEMS based current sensor that is driven by a current to voltage conversion device that converts the current in a conductor into a voltage. The other path goes to a DMEMS based electric field sensor driven by a condenser antenna that converts the electric field near a high voltage power line conductor into a voltage. The output optical signals from the current sensor and the electric field sensor are received by respective optical receivers and converted into electric signals. A signal processing unit processes the signals, and a display screen displays the results. All these are mounted on a plastic mast for handheld operation.

Abstract: An evaluation system 1 according to the present invention includes: a light source 2 for exposing a pulsed white light or a pulsed laser light onto a sample; a microwave exposing and detecting unit 8 for exposing a microwave onto an organic material 12 and for detecting the intensity of the microwave which has passed through the organic material 12; a microwave passing unit 7 for making the microwave pass through the organic material 12 a plurality of times; and an evaluating unit 10 for evaluating the photoelectric conversion characteristics of the sample based on the intensity of the microwave which has passed through the organic material 12 when the pulsed white light or the pulsed laser light is exposed and the intensity of the microwave which has passed through the organic material 12 when the pulsed white light or the pulsed laser light is not exposed.

Abstract: A test apparatus for a power supply unit is provided, which includes a body unit configured to define a space to receive a light emitting diode (LED) and to provide a test environment to test a supply state of power applied to the LED; and a test unit mounted in the body unit to face the LED and configured to detect flicker of the LED occurring when a power supply is abnormal. According to the foregoing structure, power supply with respect to the LED may be regularly detected and analyzed, thereby increasing quality of power supply with respect to the LED.

Abstract: A system for fiber DC magneto-optic detection and method thereof are provided. The system comprises a power supply and signal processing module (400), an optical fiber device (200), a magneto-optic probe (100) and a reference device (300). The reference device (300) is mounted in the system, and the measured signal can be corrected via a reference magnetic field pulse signal generated by the reference device (300) so as to eliminate the influence that the environmental factors caused on the measurement, and to obtain accurate measurement data, thus improving measurement accuracy of the system.

Abstract: Exemplary embodiments are directed to characterizing a solid state photomultiplier (SSPM). The SSPM can be exposed to a light pulse that triggers a plurality of microcells of the SSPM and an output signal of the SSPM generated in response to the light pulse can be processed. The output signal of the SSPM can be proportional to a gain of the SSPM and a quantity of microcells in the SSPM and a value of an electrical parameter of the SSPM can be determined based on a relationship between the output signal of the SSPM and an over voltage applied to the SSPM.

Abstract: The invention relates to a current determination apparatus for determining an operational driving current for driving a light source of a group of light sources. A same color shift function defining a light color shift depending on a driving current can be provided for all light sources of the group. An operational driving current is determined based on the color shift function such that the light color (43) of the light source of the group of light sources is shifted from a nominal color, which may be specific for each light source, to a light color (45) within a target color window (41). Since for the different light sources the same color shift function can be used, a determination of individual operational driving currents such that the light sources of the group emit light having substantially the same color can be simplified.

Abstract: An arrangement for measuring an internal clock within an electricity meter includes an optical communication circuit within the meter, an optical detector external to the meter, and a frequency counter. The optical communication circuit within the electricity meter is operably coupled to receive a pulse output of the meter's internal clock, and is further configured to generate a corresponding optical pulse representative of the pulse output. The optical detector is configured to detect the pulse output via an optical port of the electricity meter. The frequency counter is operably coupled to receive from the optical detector a signal that is representative of the detected pulse output.

Abstract: The invention provides an in-line power monitor for an RF transmission line that is capable of being calibrated in-line during live conditions at the exact power level and frequency where it is used. This device uses forward and reflected directional couplers and a non-directional coupler to sample the RF voltage on the transmission line. The RF voltage of the forward and reflected channels are each split into two paths, one going to a test port and the other leading to additional circuitry which prepares the signals of the forward and reflected channels for output to power displays. Additionally, the monitor allows the user to compensate for any voltage offsets introduced by various circuitry components. Further, the monitor also allows to user to individually calibrate the output of the forward and reflected channels by applying an adjustable gain ratio correction to each channel.

Abstract: A current sensor (1) that is used to detect a current that flows through a bus bar (100) includes: a base (10) that is attached to the bus bar (100); a magnetic thin film (20) that is mounted on the base (10); a luminescent device that irradiates light to the magnetic thin film (20); a photoreceptor device that detects light that is irradiated from the luminescent device to the magnetic thin film (20) and that is reflected from the magnetic thin film (20); a differential amplifier that converts an optical signal, detected by the photoreceptor device, into the current that flows through the bus bar (100); and an accommodation member (30) and pins (40) that restrict relative rotation of the magnetic thin film (20) with respect to the bus bar (100).

Abstract: DC current in a high voltage AC/DC or DC/AC converter station can be measured via the Faraday effect in one or more loops of an optical sensing fiber located at the base of a bushing extending through a wall of the hall. This arrangement can exploit the base of the bushing being at ground potential, which can simplify mounting work and maintenance.

Abstract: The present invention relates to a Faraday sensor assembly comprising a first light guiding element adapted to guide electromagnetic radiation along a first propagation direction, and a second light guiding element adapted to guide electromagnetic radiation along a second propagation direction, the second propagation direction being essentially oppositely arranged relative to the first propagation direction. The Faraday sensor assembly further comprises a measurement region arranged between the first and second light guiding elements, the measurement region being adapted to receive an electrically conducting element having, in the measurement region, its primary extension direction in a direction being essentially perpendicular to the first and second propagation directions. The present invention further relates to methods and systems for stabilizing output signal from the sensors, and to methods and systems for processing signals from the sensor assembly.

Abstract: A time-stretched enhanced recording scope (TiSER) is described using time stretch analog-to-digital conversion in a real-time burst mode. A chirped optical signal is modulated in response to receiving segments of an input signal. The optical signal with its modulated input signal, is stretched through an optical medium and digitized to represent the waveform segment. TiSER provides ultra-fast real-time sampling within short segment bursts of the original input signal while providing an ability to detect non-repetitive events. Methods and apparatus are also described for providing real-time information about inter-symbol information (ISI), rapidly determining bit-error rates (BER), performing time-domain reflectometry (TDR), generating eye diagrams for serial data, facilitating digital correction of data, clock recovery, optical carrier phase recovery, and otherwise increasing the speed and/or accuracy of a diverse range of high-speed signal measurement and processing activities.

Abstract: A voltage gradient detector provides notice when a potentially hazardous voltage gradient is present in water, employing at least one pair of spaced-apart electrodes connected to an LED. The electrode spacing is selected such that, when exposed to a sufficiently large voltage gradient, the voltage between the electrodes causes activation of the LED. The LED can provide visual illumination, or can be a part of a switching device such as a photoMOS relay that in turn activates an alarm device such as an audible sounder or a high-intensity light. Sensitivity in multiple directions can be attained by employing a pair of LEDs between the electrodes, and by employing three pairs of electrodes and associated LED pairs, with the pairs of electrodes being spaced apart along substantially orthogonal axes. These pairs may be discrete or may share an electrode in common.

Abstract: A handheld fiber optic current and voltage monitor for applications in high voltage environment. A light source generates constant optical signal that is split by a fiber optic splitter into two paths. One path feeds a DMEMS based current sensor that is driven by a current to voltage conversion device that converts the current in a conductor into a voltage. The other path goes to a DMEMS based electric field sensor driven by a condenser antenna that converts the electric field near a high voltage power line conductor into a voltage. The output optical signals from the current sensor and the electric field sensor are received by respective optical receivers and converted into electric signals. A signal processing unit processes the signals, and a display screen displays the results. All these are mounted on a plastic mast for handheld operation.

Abstract: An electric field sensor comprises an insulating substrate, a plurality of non-contacting electrodes disposed on the substrate, and a plurality of conductors coupled to the electrodes, and extending transversely through the substrate. The electrodes comprise a first electrode portion, and a second electrode portion interlaced with the first electrode portion. The conductors comprise a first conductor portion and a second conductor portion. The first portion of the conductors are coupled to the first electrode portion. The second portion of the conductors are coupled to the second electrode portion.

Abstract: An arc flash validation unit may generate stimulus to be received by an arc flash detection unit (AFDU) and observe the response of the AFDU thereto. The response of the AFDU to the stimulus may allow for validation of the AFDU (e.g., validation that the AFDU is operating as expected). In addition, the arc flash validation unit may determine the response time of the AFDU. Different types of stimulus may be provided to the AFDU, including electro-optical (EO) stimulus (e.g., visible light), current stimulus, and the like. Results of the validation may be displayed on a human-machine interface, which may display an estimate of the total energy that would be released in an actual arc flash event. The estimate may be used to define appropriate safety parameters for the equipment monitored by the AFDU.

Abstract: An optical measurement method for high-speed acquisition of integral transformed time domain optical signals is presented. A circuit network is used to generate a modulation signal and a reference signal from a broadband signal such as a pseudo random bit sequence. The integral transformed measurements are obtained by cross correlating the time dependent response to the modulated illumination with the reference signal.

Abstract: A voltage gradient detector provides notice when a potentially hazardous voltage gradient is present in water, employing a pair of spaced-apart electrodes connected to an LED. The electrode spacing is selected such that, when exposed to a sufficiently large voltage gradient, the voltage between the electrodes causes activation of the LED. The LED can provide visual illumination, or can be a part of a switching device such as a photoMOS relay that in turn activates an alarm device such as an audible sounder or a high-intensity light. Sensitivity in multiple directions can be attained by employing a pair of LEDs between the electrodes, and by employing three pairs of electrodes and associated LED pairs, with the pairs of electrodes being spaced apart along orthogonal axes. The detector can be a passive monitor housed in a floating housing, or can be a handheld device with electrode pairs that are manually immersed.

Abstract: Apparatus and methods are disclosed for obtaining an image of the impedance properties of an object by inferring a measure of straight-line path impedance along a plurality of paths from a plurality of current amplitude and phase measurements made between combinations of electrodes placed at selected points, and/or from measurements of the intensity of the electromagnetic signal emitted when an alternating current is made to resonate along the straight line path.

Abstract: The current in a generator circuit breaker is measured using the Faraday effect of an optical sensing fiber looped around the breaker's conductor. The sensing fiber is arranged in a sensing strip, which can be mounted to the enclosure of the generator circuit breaker or to the conductor. Exemplary embodiments can have a wide measuring range and can easily be fitted to new or existing generator circuit breakers.

Abstract: The present invention relates to a sensor for the detection of an analyte, comprising a fluid holder (8), an optical detection system (3, 9) for carrying out an optical detection at the fluid holder (8) and an electrical detection system (4) for measuring electric conductivity or resistance inside the fluid holder (8) and to a method comprising the use of such a sensor.

Abstract: A Fiber-optic current sensor for sensing electric current carried in an electric conductor (18). Its optical section comprises: a light source (1); a directional coupler (2) with two ports (2A, 2B) of two arms each; a radiation polarizer (3); a polarization modulator (4); a fiber line (17) coupled to a current-sensing fiber loop (11); a mirror (10); and a photodetector (22). The first port of the coupler (2) is coupled to the light source (1) and to the photodetector (22). Its second port is coupled via the radiation polarizer (3) to the polarization modulator (4). The polarization modulator comprises a magneto-sensitive element (5), around which a solenoid (6) is wound. The fiber loop (11) comprises a magneto-sensitive optical fiber with embedded linear birefringence. An electronic section comprises a signal generator (21) which drives the solenoid (6); and a signal processing unit which receives the optical signal from the photodetector (22).

Abstract: A wireless intelligent socket assembly has a wireless intelligent socket having a contact hole formed through one side thereof and electrically connected to a control circuit, a cover mounted on the top of the wireless intelligent socket and having an opening formed there through, a one connection wire and an extended antenna. One end of the connection wire is electrically connected to a corresponding contact hole, and the other end is electrically connected to an inner end of a corresponding through hole of the cover. One end of the extended antenna is electrically connected to an outer end of a corresponding through hole, and the other end extends to a location outside the wireless intelligent socket and not blocked by any foreign object. Accordingly, information detected by the control circuit can be transmitted out through the extended antenna to enhance communication performance of the wireless intelligent socket.

Abstract: An apparatus for testing photovoltaic cells wherein an array of light sources are provided. The light sources can have a collimating lens. In addition, one or more feedback circuits can be provided which monitor and maintain one or more of the light sources.

Abstract: A voltage sensor for obtaining a light signal representative of an AC voltage in a live electrical wire having a surrounding electrical field, comprising: a conducting device adapted to be placed in the surrounding electrical field and in galvanic isolation to the live electrical wire for causing a movement of charges and extracting a current from the movement of charges; a micro-light source for emitting a light signal, the micro-light source being operatively connected to the conducting device for receiving the extracted current and being directly powered by the extracted current, an intensity of the light signal being related to a value of the AC voltage in the electrical wire; a light guide, operatively coupled to the micro-light source, for receiving and propagating the light signal over a distance.