Abstract: This invention relates to a time alert device (1) for use with an earth leakage protection device comprising a microprocessor system (10) provided with a software controlled alert trigger timer (22). On time out of the alert trigger timer, the microprocessor system (10) initiates an audible and/or visual annunciation to remind the user of the earth leakage protection device to perform integrity test on the earth leakage protection device. If the earth leakage protection device fails the integrity test, the user detects that the earth leakage protection device could be faulty and needs expert attention. If the earth leakage device passes the integrity test, the alert trigger timer is reset for another predetermined time interval to remind the user to perform another integrity test on the earth leakage protection device. The time alert device can be further provided with a message display panel.

Abstract: A circuit for operating an amperometric sensor having a reference electrode, a counter electrode and a work electrode. The circuit comprises an amplifier having a positive input and a negative input and an output. The positive input is coupled to a reference voltage source, and the negative input and the output are coupled together via a negative feedback loop. The circuit includes means for coupling the amperometric sensor into said negative feedback loop of the amplifier wherein, in a first configuration, the counter electrode is coupled to said output and the reference electrode is coupled to said negative input and, in a second configuration, the work electrode is coupled to said output and the reference electrode is coupled to said negative input.

Abstract: A device and a method for estimating a current; the method includes: setting an impedance of a power gating circuit to a measurement value; wherein the power gating circuit selectively provides power to a circuit of an integrated circuit; measuring, during a measurement period, an electrical parameter indicative of a current that flows through the power gating circuit; and reducing an impedance of the power gating circuit to a power provision value to reduce a voltage developed on the power gating circuit during a power provision period.

Abstract: Voltage detecting circuit for detecting a voltage state of a voltage source includes a first route, a second route and a comparator. First route is between a voltage source and a ground voltage, having a first current source and a first MOS resistor, connected in series at a first node with outputting a first voltage. Second route is between the voltage source and the ground voltage, having a second current source and a second MOS resistor, connected in series at a second node with outputting a second voltage. The comparator receives the first voltage and the second voltage and outputs the voltage state. The comparator includes a current offset circuit for producing an offset voltage to the second voltage. A voltage comparing unit compares the first voltage and the second voltage with offset by a voltage difference, and outputs the voltage state according to variance of the voltage difference.

Abstract: The invention provides a label-free sensor that includes a substrate, a first electrode formed on the substrate, a second electrode formed on the substrate and spaced away from the first electrode, and a semiconductor layer formed on the substrate and being in contact with the first electrode and the second electrode. The semiconductor layer has a plurality of probe groups bonded to the semiconductor layer by functionalization, for sensing a coupling-specific substance having bonding specificity with the probe groups. The semiconductor layer is bonded with the probe groups, and the detection of detected object is performed in an instant, quick, rapid, and sensitive manner by measuring variation in electric current, avoiding the use of fluorescent reading equipment for reading fluorescent signals.

Abstract: According to one embodiment, a semiconductor switch includes a plurality of first switch elements, a second switch element, and a controller. The plurality of first switch elements are connected between a common terminal and each of a plurality of radio frequency terminals including a first terminal and a second terminal. The second switch element is connected between the first terminal and a ground terminal. The controller is configured to output a control signal to turn on or off the plurality of first switch elements and the second switch element and perform a normal operation mode to connect the common terminal to any one of the plurality of radio frequency terminals and a test mode to connect the common terminal to the first terminal, the second terminal, and the ground terminal according to a terminal switching signal.

Abstract: There is provided an electret microphone comprising a junction gate-field-effect transistor (JFET) and a bias resistor connected to the JFET and supplying current to the JFET, whereby an electrical output is determined by measuring a differential voltage across the bias resistor.

Abstract: An electric security fence. An electric signal generator generates an initial electric signal. The generated initial electric signal is transmitted through a transmission line. The transmission line will generate a reflected electric signal when the transmission line is disturbed by the presence of a human or animal at a disturbance area. A receiver receives the reflected electric signal and forwards it to a signal processing unit. The signal processing unit calculates the location of the disturbance area after receiving the reflected electric signal. In one preferred embodiment, the signal processing unit calculates the location of the disturbance area by determining the amount of time required for the reflected signal to travel from the disturbance area.

Abstract: An electric security fence. An electric signal generator generates an initial electric signal. The generated initial electric signal is transmitted through a transmission line. The transmission line will generate a reflected electric signal when the transmission line is disturbed by the presence of a human or animal at a disturbance area. A receiver receives the reflected electric signal and forwards it to a signal processing unit. The signal processing unit calculates the location of the disturbance area after receiving the reflected electric signal. In one preferred embodiment, the signal processing unit calculates the location of the disturbance area by determining the amount of time required for the reflected signal to travel from the disturbance area.

Abstract: The present invention employs identically sized mirror transistors arrange in groups that may be preferentially addressed and activated to determine the value of a resistor. Known current are directed through the resistor, and the voltage developed is measured by comparing against a reference voltage. The current is increased or decreased by the least significant value until the voltage across the resistor matches the reference voltage. A successive approximation or other known technique may be used instead. A reference current is developed that temperature stable and that is trimmed when manufactured to reduce process effects. The reference voltage may be constructed to be independent form a local power source so that the system is relatively independent of process, voltage and temperature, PVT.

Abstract: A process device is configured to meet a desired Safety Integrity Level (SIL). A device interface is configured to couple to the process device and provide an output related to operation of a component of the process device. A component monitor monitors operation of the component and identifies a safety event of the component. A safety response module responds to a safety event of the component in accordance with a safety response.

Abstract: An arrangement for detecting plasma instability within a processing chamber of a plasma processing system during substrate processing is provided. The arrangement includes a probe arrangement, wherein the probe arrangement is disposed on a surface of the processing chamber and is configured to measure at least one plasma processing parameter. The probe arrangement includes a plasma-facing sensor and a measuring capacitor, wherein the plasma-facing sensor is coupled to a first plate of the measuring capacitor. The arrangement also includes a detection arrangement, which is coupled to a second plate of the measuring capacitor. The detection arrangement is configured to convert an induced current flowing through the measuring capacitor into a set of digital signals, the set of digital signals being processed to detect the plasma instability.

Abstract: A storage battery inspecting system includes a power supply unit and an inspecting unit. The inspecting unit includes two inspecting terminals to be connected to a battery soldering spot so as to detect response of the soldering spot to application of a test power signal by the power supply unit, and a control module for determining if a detected response of the soldering spot falls within a predetermined range configured in the control module, generating an indication signal if the detected response falls outside the predetermined range, and generating an inspection result corresponding to the detected response. The inspecting unit further includes an indication interface for outputting the indication signal, a transmission interface permitting supply of the inspection result to a processing device, and a control interface permitting supply of a control signal generated by the control module to a peripheral device for controlling operation of the peripheral device based on the detected response.

Abstract: A structure is described that includes a first faying surface, a second faying surface for creating an electrical bond with the first faying surface, and a sensor operatively placed proximate the first faying surface and the second faying surface. The sensor includes a current port for injecting a fixed current through the electrical bond, a voltage port for sensing a voltage across the electrical bond induced by the fixed current, a processing device programmed to determine a resistance of the electrical bond based on the fixed current and sensed voltage, and a wireless interface for transmitting at least one of the sensed voltage and the determined resistance to an external device.

Abstract: The subject matter of the invention is a method of measuring a grounding current of a photovoltaic power system incorporating a photovoltaic inverter, a measurement current being led through two shunts (Rs1, Rs2) disposed at different points, the measurement current being a current that may flow alternatively at two different points at different electric potentials, the current flowing at a potential that differs by at least 50 V from the potential of the point of evaluation, the shunts (Rs1, Rs2) being inserted in such a manner in a current mirror circuit that the voltage drop caused by the measurement in the shunts generates an asymmetry in the current mirror the magnitude of which is proportional to the measurement current, and the measurement current being the grounding current of the photovoltaic power system with optional positive or negative pole grounding.

Abstract: Provided is a test apparatus that tests a device under test, including a power supply that generates supply power supplied to the device under test, a transmission path that transmits the supply power generated by the power supply to the device under test, an intermediate capacitor that is provided between the transmission path and a ground potential, a power supply current measuring section that measures a current flowing through the transmission path at a position closer to the power supply than the intermediate capacitor, a charge and discharge current measuring section that measures a charge and discharge current of the intermediate capacitor, and a load current calculating section that calculates a load current flowing through the device under test based on a sum of the current measured by the power supply current measuring section and the current measured by the charge and discharge current measuring section.

Abstract: An automotive vehicle electrical system tester is provided for testing an electrical system having wiring which couple a load to a battery. The automotive vehicle electrical system tester is configured to measure an electrical parameter of the wiring and includes a first battery terminal connection configured to couple to a first terminal of the battery. A test connection is configured to couple to a wire of the electrical system which extends between the first terminal of the battery and the load. Test circuitry coupled to the first battery terminal connection and the test connection is configured to draw current from the battery along a path through the wire and to the test connection. The test circuitry measures an electrical parameter of the wire.

Abstract: Some embodiments of the present invention describe an apparatus that includes an oscillator, a ramp generator, and an inverter. The apparatus includes an oscillator, an inverter, and a ramp generator. The oscillator is configured to generate a waveform comprising a low time and a high time. The inverter is configured to receive the waveform generated by the oscillator, and invert the waveform. The ramp generator configured to increase a gate control voltage of a transistor connected to a solar cell, and rapidly decrease the gate control voltage of the transistor. During the low time of the waveform, a measurement of a current and a voltage of the solar cell is performed as the current and voltage of the solar cell are transmitted through a first channel and to a second channel.

Abstract: The invention relates to a testing apparatus for testing a 5-wire resistive touch panel of an electronic system. The testing apparatus comprises a voltage control unit, a signal control unit, an electronic unit and a determining unit. The electronic unit is used for generating at least one output signal corresponding to a first voltage level and a second voltage level generated by the voltage control unit and a detecting signal generated by the signal control unit. The determining unit coupled to the electronic unit is used for determining the status of the electronic unit according to the at least one output signal.

Abstract: The present teachings relate to the application of electrical impedance tomography (EIT) to demonstrate the multifunctionality of carbon nanocomposite thin films under various types of environmental stimuli. Carbon nanotube (CNT) thin films are fabricated by a layer-by-layer (LbL) technique or other techniques and mounted with electrodes along their boundaries. The response of the thin films to various stimuli determined by relying on electric current excitation and corresponding boundary potential measurements. The spatial conductivity variations are reconstructed based on a mathematical model for the EIT technique. Here, the ability of the EIT method to provide two-dimensional mapping of the conductivity of CNT thin films is validated by (1) electrically imaging intentional structural defects in the thin films and (2) mapping the film's response to various pH environments.

Abstract: A method includes calculating a number of turns of a shield winding included in an energy transfer element of a power supply, where the calculating is to have a low noise current in an input conductor of the power supply. The method further includes: increasing the number of turns for the shield winding; operating the power supply; and adjusting a value of a shield impedance to substantially reduce the noise current. An apparatus includes a power supply having an energy transfer element and a shield impedance. The energy transfer element includes a shield winding having an end terminated externally to the energy transfer element. The shield impedance is coupled between the externally terminated end of the shield winding and an input conductor of the power supply, where the shield impedance has a non-zero finite impedance value to substantially reduce a noise current in the input conductor.

Abstract: A sensor system having a sensor unit for detecting a measured variable, and an evaluation unit, which are interconnected via at least one or a plurality of connection line(s), the sensor unit having a sensor, which is connected to a supply voltage, and includes a signal output for a measuring signal that is a function of the measured variable, the evaluation unit having a voltage meter to detect the status of the measured variable as a function of a potential, the sensor unit including a first resistive circuits connected to the sensor, and the evaluation unit including a second resistive circuit connected to the voltage meter. The first and the second resistive circuits are coupled to one another via at least the sensor line and forming a resistor network.

Abstract: A method and device for determining the linear response of an electrical multi-port component has an “estimation procedure” in which an estimated admittance matrix is determined by applying voltages to the ports of the component and measuring the response of the component. The estimation procedure can e.g. consist of a conventional measurement of the admittance matrix. The method further has a “measurement procedure” in which several voltage patterns are applied to the port. The voltage patterns correspond to the eigenvectors of the estimated admittance matrix. For each applied voltage pattern, the response of the component is measured. This allows to measure the linear response of the component accurately even if the eigenvalues of the admittance matrix differ by several orders of magnitude.

Abstract: An exemplary signal interference control system is disclosed that utilizes a computer system, such as programmable logic circuits or computer controlled logic gates, to generate blanking or control signals for various types of radio frequency receiver and transmitter combinations. Control signals are generated based on signal characteristic information stored in a memory including a delay following receipt of a pre-trigger signal from a radio frequency transmitter and a pulse width of control signal(s) generated for specified receivers, frequencies or systems. In one embodiment, information can be retrieved from a memory and used to generate an interference control signal. One or more control signals can be routed to a related or associated receiver to reduce or eliminate interference effects.

Abstract: A current measuring apparatus is disclosed. The current measuring apparatus comprises a power supply unit, an impedance setting module, and a current measuring unit. The power supply unit is adapted to provide an electric power to an electronic apparatus. The impedance setting module is adapted to provide at least one impedance value to the electronic apparatus so that the electronic apparatus is able to be activated in response to the electric power and the impedance value. The current measuring unit is adapted to show a current consumption value of the electronic apparatus under the activated state.

Abstract: A method of determining the diameter of a hole extending from a surface of an electrically conducting workpiece into or through the workpiece 1 is provided. The hole is defied at the workpiece's surface by an edge of diameter to be determined. For determining the diameter, the workpiece is electrically charged so that discharge occurs at the edges. The discharge current is measured and the diameter of the hole is determined from the measured discharge current.

Abstract: A semiconductor integrated circuit device including a semiconductor substrate having a first surface on which a circuit block is formed, and a second surface opposite to the first surface; a mounting board on which the semiconductor substrate is mounted; an electrically conductive pattern formed over a region of the mounting substrate, which overlaps a portion to be protected of the circuit block; and a detection circuit configured to detect that the electrically conductive pattern has been altered is provided. The semiconductor substrate is mounted on the mounting board such that the second surface of the semiconductor substrate faces the mounting board.

Abstract: A capacitance-to-voltage interface circuit is utilized to obtain a voltage corresponding to a detected capacitance differential, which may be associated with the operation of a capacitive sensing cell. The interface circuit includes a capacitive sensing cell, an operational amplifier adapted for selective coupling to the capacitive sensing cell, a feedback capacitor for the operational amplifier, a load capacitor for the operational amplifier, and a switching architecture associated with the capacitive sensing cell, the operational amplifier, the feedback capacitor, and the load capacitor. During use, the switching architecture reconfigures the capacitance-to-voltage interface circuit for operation in a plurality of different phases. The different operational phases enable the single operational amplifier to be used for both capacitance-to-voltage conversion and voltage amplification.

Abstract: A method for detecting a damaged magnetoresistive sensor in one embodiment includes measuring a resistance of a first sensor upon application thereto of a positive bias current; measuring the resistance of the first sensor upon application thereto of a negative bias current; determining a difference in the measured resistances at positive and negative currents of the first sensor; measuring a resistance of a second sensor upon application thereto of a positive bias current; measuring the resistance of the second sensor upon application thereto of a negative bias current; determining a difference in the measured resistances at positive and negative currents of the second sensor; and outputting at least one of the differences, or a derivative of the at least one of the differences. Additional methods are also presented.

Abstract: A device for measuring the resistivity ?c of an interface between a semiconductor and a metal, including at least: one dielectric layer, at least one semiconductor-based element of a substantially rectangular shape, which is arranged on the dielectric layer, having a lengthwise L and widthwise W face in contact with the dielectric layer and having a thickness t, and at least two interface portions containing the metal or an alloy of said semiconductor and said metal, wherein each of two opposing faces of the semiconductor element, having a surface equal to t×W and being perpendicular to the face in contact with the dielectric layer, being completely covered by one of the interface portions.

Abstract: Methods and apparatus characterized by distinct operating modes are provided. A thin graphite material defined by graphene layers is supported on a silicon substrate. The graphite material is defined by edge sites at the interface with the silicon. The graphite material is characterized by electrical superconductive-like behavior at room-temperatures while electrical current flows there through in a first direction. The graphite material is further characterized by a transition to Ohmic behavior while electrical current flows there through in a second direction opposite to the first. Devices exhibiting diode-like behavior can be formed accordingly.

Abstract: The present invention is a method for evaluating a silicon wafer by measuring, after fabricating a MOS capacitor by forming an insulator film and one or more electrodes sequentially on a silicon wafer, a dielectric breakdown characteristic of the insulator film by applying an electric field from the electrodes thus formed to the insulator film, the method in which the silicon wafer is evaluated at least by setting an area occupied by all the electrodes thus formed to 5% or more of an area of a front surface of the silicon wafer when the one or more electrodes are formed. This provides an evaluation method that can detect a defect by a simple method such as the TDDB method with the same high degree of precision as that of the DSOD method.

Abstract: An insulation measurement apparatus includes a path including a first resistor, a capacitor electrically floated from a ground, and a second resistor between a positive to a negative electrode side of a power supply, a first switching element between the power supply positive electrode side and the capacitor, a second switching element between the capacitor and the power supply negative electrode side, a detection section detecting a charge voltage on the capacitor and determining a power supply insulation state, and a voltage setting section executing a power supply voltage measurement mode controlling the first and second switching elements to charge the capacitor for a predetermined time period, and an insulation voltage measurement mode charging a terminal of a positive or negative electrode side of the capacitor via a resistor between the power supply positive or negative electrode and the ground for a predetermined time period.

Abstract: An apparatus for monitoring line voltage in a circuit breakor includes a controller configured to calculate a voltage difference between the neutral voltage and the AC line voltage of positive polarity based on a first signal and a second signal and assign, using a polarity signal, the voltage difference value to the AC line voltage of positive polarity and the second signal to the AC line voltage of negative polarity. Because the AC line voltage of positive polarity can be calculated based on the first signal and the second signal, the number of signals requiring A/D conversion is reduced, and the number of circuit components needed to measure the AC line voltage is reduced.

Abstract: A logarithmic level detector (9) produces analog signals that represent logarithms of the voltage across, and current through, a target device (7). These signals are then passed to a processor (1) that performs a digital conversion. Because the digital conversion takes place after logarithmic conversion, it becomes possible to obtain an appropriate resolution for all signal levels, and a calculation of impedance of a target device, with reduced error, is enabled.

Abstract: A magnetic memory device includes a magnetic tunnel junction having a free magnetic layer having a magnetization orientation that is switchable between a high resistance state magnetization orientation and a low resistance state magnetization orientation and a memristor solid state element electrically coupled to the magnetic tunnel junction. The memristor has a device response that is an integrated voltage versus an integrated current.

Abstract: A device having a switch with a voltage applied across the switch. A current sensing circuit is connected to one terminal of the switch. The current sensing circuit receives power independently of the voltage applied across the switch. The power supply shares the other terminal of the switch with the current sensing circuit. The switch is adapted for opening and closing. When the switch closes, the current sensing circuit senses current through the switch and upon opening the switch the high voltage of the switch is blocked from the current sensing circuit. The sense current is caused to flow from the current sensing circuit to the other terminal when the switch is closed. The flow of the sense current produces a voltage which is compared differentially to another voltage referenced by the other terminal.

Abstract: The Universal Power Inlet System, or UPIS, is a method of providing universal attachment of 3 different types of electrical power systems into the input circuitry of a Power Distribution Unit, or PDU. This method allows use of either fixed or detachable power cord options permitting the PDU to be powered by any of the following types of electrical power sources: 3-Phase Delta, 3-Phase Star (or Wye) and Single-Phase. This method also describes a way to uniquely identify the specific power system the mentioned PDU is currently attached to. The method also optionally allows derivation of supplementary information about the electrical power system such as current capacity, or ampacity, of the power cord being used. All this information can be used for capacity monitoring and reporting as well as protection of PDU circuitry and power cords.

Abstract: A combined electrical variable detection device comprises a plurality of single-phase current measuring modules (1) arranged in a common frame (2) and having a separate output cable/connection (8) for each module (1). At least one single-phase current measuring module (1) is provided with a voltage detection device. Preferably, the device uses one output cable/connection (7), the signal wires of which are coupled to said output cable/connections (8) from said modules (1). Preferably all single-phase current measuring modules (1) are provided with Rogowski coils as measuring elements. In one embodiment, the combined electrical variable detection device has a residual-current detection device (3) an/or a residual-voltage detection device surrounding more than one of said single-phase current measuring modules (1) in said common frame (2).

Abstract: A junction-current probe is provided which can measure a current flowing in a junction port adapted to connect a circuit board or an electronic apparatus to a chassis under the condition that the circuit board or electronic apparatus is packaged to the chassis. Structurally, the current probe has a circular or rectangular insulator having a hole in the center, a coiled conductor wire for converting linkage flux into voltage, an insulating member for preventing the insulator from making electrical contact with surroundings, an extraction lead for connecting opposite ends of the conductor wire to a cable and the cable for connection to a measurement unit. The current probe is reduced in thickness within in a range in which the condition of packaging to the chassis can remain unchanged.

Abstract: A method and circuit is provided for implementing high current capability Kelvin connections and measuring the resistance of the contacts and connections to verify that the conducting path is capable of carrying the high current without damage or degraded performance. Included as well is the means and circuit for efficiently dividing a high current test stimulus current into 2 or more paths with low losses and voltage drops.

Abstract: A resistance measuring circuit includes a current generating component, a current control component, and a voltage measurement component. The magnitude of a target resistance can be measured by connecting the target resistance between first and second measurement terminals of the resistance measuring circuit, applying a current generated by the current generating component to the target resistance, and determining the voltage across the target resistance. When no target resistance is connected between the first and second measurement terminals, the current control component controls the current generating component to reduce current consumption of the resistance measuring circuit.

Abstract: To characterize an electrical cable that is deployed in a well, a voltage input is applied to the electrical cable at an earth surface location, where the well extends from the earth surface location. A current response resulting from the voltage input is measured at the earth surface location. At least one parameter of the electrical cable is computed according to the measured current response.

Abstract: A cementitious compound provides a brittle undercoat for making a surface-mounted crack sensor on a surface. A low percent elongation and low tensile strength of the cementitious compound have proven valuable in ensuring that cracks in the underlying surface are transmitted through the undercoat so that a trace of conductive ink or paint on the undercoat more reliably detects the crack.

Abstract: A method of providing an image of an interior of a structure containing regions having different conductivities or admittivities. In one embodiment a series of electrical signal sets is applied to a series of electrodes, each signal set generating a rotating electric field. A measured set of electrical signals obtained from the electrodes are used to calculate a conductivity or admittivity distribution representative of the interior of the structure in a region about which the electrodes are positioned. The process of calculating the distribution includes defining a cost function, e.g., the energy function based on the distribution, and a forward model expressing the measured set of electrical signals as a function of the change in voltage values with respect to conductivity or admittivity and requiring that the partial derivative of the difference between the energy function and a function based on the forward model equal zero.

Abstract: Embodiments of an apparatus for measuring the leakage current of capacitive components is taught. One embodiment includes a first stage amplifier configured to receive an input from a serially-connected capacitive component at an inverting input and a feedback resistor in a feedback path of the first stage amplifier. A resistance value of the feedback resistor is programmable based on an expected value of the leakage current and a corresponding voltage output.

Abstract: A device having a switch with a voltage applied across the switch. A current sensing circuit is connected to one terminal of the switch. The current sensing circuit receives power independently of the voltage applied across the switch. The power supply shares the other terminal of the switch with the current sensing circuit. The switch is adapted for opening and closing. When the switch closes, the current sensing circuit senses current through the switch and upon opening the switch the high voltage of the switch is blocked from the current sensing circuit. The sense current is caused to flow from the current sensing circuit to the other terminal when the switch is closed. The flow of the sense current produces a voltage which is compared differentially to another voltage referenced by the other terminal.

Abstract: An alternating current (AC) to direct current (DC) power converter may have a connector with a pair of power supply contacts and a pair of data contacts. An electronic device may be connected to the connector of the power converter. The power converter may supply DC power to the electronic device using the power supply contacts. The power converter may include control circuitry that has a resistor coupled across the data contacts. When the electronic device and the power converter are connected to each other, each may advertize to the other that capabilities are present that exceed industry standards. At the same time, standard-compliant discovery operations may be performed to probe the value of the resistance of the resistor that is coupled across the data contacts. When extended capabilities are discovered, extended functions may be performed including accelerated charging functions and data communications functions.

Abstract: An interface circuit includes a reference voltage generation circuit to generate a reference voltage, a differential voltage signal generation circuit to convert send data input in sending data into a pair of differential voltage signals and output the pair of differential voltage signals based on the reference voltage generated by the reference voltage generation circuit, a receiver to convert a pair of differential voltage signals input in receiving data and output received data, and a receiver test circuit to perform a sensitivity test of the receiver, the receiver test circuit having a resistance circuit to generate a pair of differential voltage signals having a potential difference being necessary for the sensitivity test of the receiver.

Abstract: A cathodic protection monitor to be electrically connected to a cathodic protection rectifier that is adapted to prevent rust, corrosion and possible leakage in an underground pipe or storage tank above which the rectifier is supported. The cathodic protection monitor includes a CPU that reads, digitizes and stores analog current and voltage signals which are indicative of the effectiveness of the rectifier. The monitor includes an ISM band transceiver and antenna by which the CPU is polled and from which packets of stored data are transmitted to a data collector for retransmission and analysis by the pipe owner or maintenance crew. Synchronized timing signals are supplied (from the National Bureau of Standards) to a stable auxiliary clock by way of a WWVB transceiver and antenna so that a plurality of cathodic protection rectifiers can be turned on and off at the same time as may be required to compile ground voltage readings along the pipeline as part of a government-mandated survey.