Abstract: A power strip is providing including a housing coupled to a first end portion of a power supply cord, the housing having an electrical receptacle mounted thereto and connected to the power supply cord, the power supply cord having a second end connectable to a power source. A current sensor is coupled to the power supply cord between the electrical receptacle and the second end for detecting electrical current flow through the power supply cord and providing an output signal that varies in proportion to the current flow through the power supply cord. A processing circuit coupled to the output of the current sensor includes a display device for displaying at least one of the current, voltage, power, and phase associated with the power supply cord at the current sensor. The display device can be remotely coupled to the power strip for positioning the display in a convenient location.

Abstract: A current monitoring device (CMD) with a set of electromagnetic field sensors located within one or more grounded housings positioned within the combined electromagnetic fields generated by one or more electric power lines. The CMD includes electronics, typically located within the grounded housings, defining impedance networks that combine the measurements received from the field sensors to create output signal indicative of electric current values for the phase conductors. The housings can be conveniently attached and to transmission line towers, distribution line poles, and high voltage power line supports in transmission and distribution substations. The CMD controls response equipment, such as a circuit interrupter that responds to current disturbances detected by the CMD. The CMD may also include communication for sending the current values to a remote controller, such as a central control station, that implements a wide range of response equipment.

Abstract: There is provided a method for measuring a parameter of a power frequency current being carried by a power line. The method that includes (a) transducing a power frequency current flowing through a power line, into a power frequency voltage, via an inductive coupler that couples a communications signal from the power line, (b) separating the power frequency voltage from the communications signal, and (c) determining a value of a parameter of the power frequency current from the power frequency voltage. There is also provided a system and an apparatus for measuring the parameter.

Abstract: Reverse bias voltage VM is applied to any one of self light emitting elements arranged on a light emitting panel 1 under detection mode. Current corresponding to weak current flowing to the element is supplied to a transistor Q3 by the operation of a current mirror circuit comprised of transistors Q1, Q2. The current mirror circuit is formed with the transistor Q3 as a control side current source transistor and transistors Q4 to Q7 as a controlled side current source transistor. The sizes of the controlled side current source transistors Q4 to Q7 are set to, for example, 1:2:4:8 with respect to the control side current source transistor Q3 so as to construct current amplifying means. Current value amplified by a current comparison type comparator 7 is compared with current value from a reference current source 8 and its output is latched by a latch circuit 9 and stored in a data register 10.

Abstract: A load status indicator is disclosed wherein a green light-emitting diode of a bi-color light-emitting diode lights up when power is available to but not being used by a monitored device, whereas a red light-emitting diode of the bi-color light-emitting diode lights up when the monitored device is drawing current. The load status indicator utilizes a coil in series with the monitored device, a reed switch controlled by the coil, and field-effect transistors to control which light-emitting diode lights up depending on whether power is available and whether the monitored device is drawing current.

Abstract: Techniques are disclosed to sense a current in a circuit. For instance, current sense circuit according to the teachings of the present invention includes a current sense resistor coupled to an input of the current sense circuit. The current sense resistor is coupled to receive a current to be sensed from the input of the current sense circuit. The current to be sensed is converted to a current sense voltage. A first PN junction diode is coupled to the current sense resistor. A light emitting diode (LED) is coupled to the first PN junction diode to provide a current sense threshold substantially proportional to a difference between a forward voltage drop of the LED and a forward voltage drop of the first PN junction diode. The first PN junction diode is coupled to be biased from the forward voltage drop of the LED. The LED is coupled to the current sense resistor to generate an output when the current sense voltage from the current sense resistor reaches the current sense threshold.

Abstract: A status indicator indicates an operating state, including an electrical malfunction, of an electrical load that is located and controlled from locations remote from a monitoring location.

Abstract: According to some embodiments, a Microelectromechanical System (MEMS) sensor includes a sensing portion that generates a mechanical movement in response to a measurand input. The sensor also includes a logic portion to mechanically perform a logic function in response to the movement.

Abstract: Heating coils used in an electric furnace used to process semiconductor wafers are monitored on a real time basis by sensing the AC current in a power line delivering electrical power to the furnace. The AC current is sensed by a coil positioned around and magnetically coupled with the power line. The sensed AC current induces an AC voltage in the coil which is converted by an electrical circuit into a DC voltage. The DC voltage is used to control a solid state relay that generates an alarm signal when the value of the DC voltage is less than a preselected value indicating that an open circuit is present in the heating coil.

Abstract: A device for detecting disconnection for use in a stepping motor driver is provided having a driver circuit 3 which comprises a pair of windings 21, 22 wound in a bifilar turn arrangement; a pair of MOSFETs 1, 2 connected to the other end of each winding 21, 22; a common current detecting resistor 4 connected between MOSFETs 1, 2 and ground; a first reference voltage generator 34 for producing a first reference voltage Vt1; a second reference voltage generator 40 for producing a second reference voltage Vt2 lower than first reference voltage Vt1; a decision circuit 8, 8b for comparing the detection voltage on current detecting resistor 4 with second reference voltage Vt2 to produce an alarm signal when detection voltage is higher than second reference voltage Vt2; and a disconnection detector 11 for receiving an alarm signal from decision circuit 8, 8b after comparator 8 produces a chopper signal 17 to produce a disconnection signal upon occurrence of line-disconnection in winding 21 or 22.

Abstract: A hand tool which provides an alarm signal to a user as the tool approaches a live electrical wire is disclosed. The hand tool comprises a tool head and coupled to a handle. A non-contact voltage sensing circuit is provided in the handle of the tool. As the tool approaches a live electrical wire, the non-contact voltage sensing circuit detects the voltage across the air gap between the tool head and the electrical wire, triggering an alarm circuit. The alarm circuit provides a visual or audio signal to the user.

Abstract: A vacuum tube replacement device includes an indicator. The indicator can be arranged to provide audible and/or visual indication of system performance, function, status, or any other desired indication. The vacuum tube replacement device is pin-for-pin compatible with standard vacuum tube circuit pin configurations. The replacement device may be a solid-state tube emulator device, a traditional glass envelope vacuum tube device, or some other hybrid device. The visual indicator is equally useful for non-vacuum tube replacement devices such as audio amplifier circuits.

Abstract: A process device is configured for coupling to a two wire process control loop. Loop current output circuitry is configured to apply an output current to the two wire process control loop. Loop current verification circuitry is coupled to the two wire process control loop and configured to detect errors in the applied output current. At least a portion of the loop current verification circuitry is independent from the loop current output circuitry.

Abstract: A control unit for a microscope, a stereomicroscope, or an industrial image processing machine is described, to which at least three lighting units, e.g. for incident light-bright field illumination, incident light-dark field illumination, and for transmitted light illumination, are connected. Respective lighting units are simultaneously controlled according to user commands, e.g. for interval control to simulate a moving light source. The user commands can be input by function keys and/or a foot switch and/or stored in a memory provided in the control unit. Alternatively or in addition, the control unit can receive command statements from an external computer connected via an interface or control signals from an external camera. The control unit detects temperatures of the lighting units and shuts off a lighting unit or generates a warning signal when its temperature becomes excessive.

Abstract: A method and system for detecting whether an antenna is property connected to a distributed antenna network. The current drawn by the antenna is measured and compared against an expected current draw or reference level. The measured level of current drawn by the antenna is indicative of whether the antenna is properly connected or is disconnected. The comparison results may be used as the basis for creating a status message, which is then communicated to a central monitoring unit for each antenna. The central monitoring unit may generate appropriate alarms in response to a status message indicating a fault condition at a particular antenna.

Abstract: A Radio-Frequency Identification (RFID) transponder is provided. The RFID transponder may include a basic ID flag circuit having a VDD voltage node, an output voltage node, and a capacitor coupled to the VDD voltage node and the output voltage node to store an ID flag. A supplemental discharge current circuit coupled to the basic ID flag circuit is provided in order to control persistence duration of the state of the ID flag. The persistence duration of the state of the ID flag is controlled by maintaining supplemental discharge current, which is greater than the leakage current of the basic ID flag circuit.

Abstract: Low threshold current switch comprising a sensing transformer, a voltage multiplier and a switch enables monitoring a very low electric current in a power cable.

Abstract: Track anomalies are detected by measuring track impedance. A robotic device is moved along the track. A conductor on the track is contacted with a pair of pickups moved by the robotic device. Track health is determined based on impedance sensed between the pickups.

Abstract: A control unit for a brushless motor has an upper-arm current detector for detecting an electric current flowing into an upper-arm switching transistor for driving the brushless motor, and a lower-arm current detector for detecting an electric current flowing into a lower-arm switching transistor. The control unit controls the current that flows into the brushless motor based on the upper-arm current value when it is so determined that the lower-arm current value cannot be detected. The control unit detects abnormal condition in the first current detector based on the upper-arm current value.

Abstract: The brush abrasion detector is unnecessary to provide any detecting element for detecting limit of abrasion of a brush in the proximity of the brush. The brush abrasion detector includes: a brush located being slidably press-fitted to a slip ring provided at an end portion of a field winding of a generator, and supplying an excitation current from a battery to the field winding; a current detection circuit for detecting a current value flowing through the field winding via the brush; an output voltage detection circuit for detecting an output voltage value from the generator; and a brush abrasion determination circuit for determining abrasion state of the brush based on a current value detected by the current detection circuit or an output voltage value detected by the output voltage detection circuit.

Abstract: An electric power steering system comprises a three-phase brushless DC motor, a steering torque detector, a resolver for detecting a resolver rotation angle of the three-phase brushless DC motor, a processing unit and a failure detection apparatus. The processing unit supplies a motor rotation angle and a rotational direction command value to the failure detection apparatus. The failure detection apparatus determines whether the processing unit is normal based on the motor rotation angle and the rotational direction command value.

Abstract: The present invention provides a new application for an inductive coupler (12) used proximate a power transmission line (14). The magnetic field based power measurement method and system discussed herein in unique and differs from the prior technology by using near-real time intervals and periods that occur systemically in parallel with electrical systems rather than an accumulated period with little or no active capacity or proactive features. The inductive coupler (12) described herewith is used to collect, measure, and/or extract electromagnetic changes.

Abstract: An apparatus and method for detecting a connection to a data transmission network functions by detecting the network signal energy on a network cable while avoiding the problems of excessive power consumption and generation of excessive electrical noise. By monitoring the receive network lines and determining if there is electrical energy on the cable in the form particular to the type of network supported by the network adaptor card, the host computing device can power-down the transceiver associated with the network adaptor card until an active network connection is detected.

Abstract: An evaluator (210) having an input (207) for receiving a signal indicative of a channel current sensed via a sensor in a mutlichannel current sharing system, and circuitry (313, 319) coupled to the input (207) and responsive to the signal for indicating an unreliable sensing for the sensor when a low current condition occurs for a time period exceeding the switching time period of the channel current. Further, the apparatus can include an additional input (207) and circuitry (313, 319) for evaluating an additional sensor sensing an additional channel current. The low current condition is characterized by thresholds corresponding to the peak level and a valley level of the channel current over a switching time period.

Abstract: A Radio-Frequency Identification (RFID) transponder is provided. The RFID transponder may include a basic ID flag circuit having a VDD voltage node, an output voltage node, and a capacitor coupled to the VDD voltage node and the output voltage node to store an ID flag. The persistence duration of the state of the ID flag is controlled by maintaining a charge and leakage circuit. The charge and leakage circuit includes an NMOS device having a source, a drain and a gate, the source node of the NMOS device being coupled to the capacitor and the drain node of the NMOS device being coupled to a first CMOS inverter. The first CMOS inverter is powered by a regulated supply voltage such that the voltage on the capacitor is not dependent on the forward voltage drop of the NMOS device.

Abstract: A fault condition monitoring apparatus for use with a fuse cutout includes a housing operable to be supported by the fuse cutout. The housing has first and second contacts operable to make electrical contact with fuse contacts on the fuse cutout when the housing is supported by the fuse cutout. A current sensor is mounted inside the housing and is connected to the first and second contacts. A signaling device is coupled to the current sensor and is operable to cause a signal to be produced when current sensed by the current sensor meets a criterion.

Abstract: A fault indicator for indicating the occurrence of a fault in an electrical conductor is automatically configured for an overhead application or for an underground application. The fault indicator has a housing, a battery, a display for indicating the occurrence of a fault, a current sensor for sensing the load current in a monitored conductor, and electromagnetic field sensor to sense the electromagnetic field about the conductor, and a microcontroller for determining whether a fault condition occurred, for determining the magnitude of the electromagnetic field, and for configuring the fault indicator in the overhead configuration if the electromagnetic field is above a predetermined magnitude or configuring the fault indicator for the underground mode if the field is below the predetermined magnitude.

Abstract: A process device for use in a process control system includes output circuitry configured to couple to a process control loop. The output circuitry controls electrical current through the loop. Loop override circuitry is configured to override operation of the output circuitry and set the electrical current in the loop to a desired level.

Abstract: A transmitter for a line locator system that controls the electrical current, voltage or power applied to the target line is disclosed. Control of the electrical output of the transmitter can be achieved passively or by means of a feedback control system. A transmitter connected directly to a line can include an operator control and monitoring of current being supplied to a line to be located. Some transmitters include a current regulating circuit that controls current supplied to a line. In some transmitters, feedback controllers and feedback loops are used to regulate output current, voltage or power. Some control loops are based on monitoring currents in circuits; some control loops monitor power output from an inductive mode transmitter antenna. An inductively coupled transmitter with power output control is also disclosed.

Abstract: An electric power line characteristic apparatus and monitoring method allows automatic conductor current data logging of maximum current magnitudes and data storage for later retrieval in a remote electric power line conductor faulted circuit current monitoring system 2. The apparatus and method includes, from a remotely located exciter 3 apparatus using an antenna 5 to transmit a specific frequency and code key to an antenna 10 of an electric power line conductor faulted circuit current monitoring apparatus associated with the electric power line phase conductor. Additionally the method and apparatus includes a delay circuit to allow a fixed delay time before the faulted circuit monitor responds to the instantaneous re-application of power to the conductor after a fault. This fixed period of time for the current to settle to a nominal value constitutes an inrush delay time before the faulted circuit monitor responds to the current level flowing in the power line.

Abstract: A universal vehicle electric power distribution module employs reconfigurable inputs and outputs enabling use of the same hardware across vehicle lines. The module is scalable for ease of expansion and is capable of handling both low current and high current load management on the same module.

Abstract: Disclosed herein is a method and system for calibrating line drive currents in systems that generate data signals by varying line drive currents and that interpret the data signals by comparing them to one or more reference voltages. The calibration includes varying the line drive current at a transmitting component. At different line drive currents, a receiver reference voltage is varied while the transmitting component transmits data to a receiving component. At each line drive current, the system records the highest and lowest receiver reference voltages at which data errors do not occur. The system then examines the recorded high and low receiver reference voltages to determine a desirable line drive current.

Abstract: A system that monitors at least a household electric user (HA1–HA4), in particular a household appliance, includes a monitoring device (MSA) that is connected between a source of electric energy (OUT) and the electric user, the monitoring device (MSA) including a metering means for detecting one or more electric quantities being associated with the operation of said user (HA1–HA4), and further including a control means that is programmed for (i) comparing the electric quantity or quantities being measured through the metering means with reference values of said electric quantity or quantities which are stored within the control means; (ii) generating, in function of the comparison, information being representative of the current operating status or phase of operation of the electric user (HA1–HA4); and (iii) allowing for the reading or transmission of the information to the outside of said device (MSA).

Abstract: A warning device including a status and function indicator circuit for indicating the status and function of the warning device. In a visual warning device such as a strobe light, the status and function indicator circuit includes a status output device such as an LED. The LED and associated circuitry are configured to indicate both proper operation of the visual warning device and, in the event of a device failure, will indicate whether the fault lies with circuitry for the visual warning device or simply with a warning output device.

Abstract: A process device for use on an industrial process control system includes a quiescent current sensor configured to sense quiescent current draw of the process device. Diagnostic circuitry determines a diagnostic condition of the process device as a function of the sensed quiescent current.

Abstract: A device comprising a housing, a battery source, a transformer, a light, a radio, and a clock. The battery source is held in the housing and provides a first source of direct current (DC). The transformer, which is also held in the housing, is configured for receiving an alternating current (AC) from a source of AC and for converting the AC to a second source of DC. The light, the radio and the clock are also held in the housing. The light, the radio and the clock are operatively connected to the battery source and the transformer to receive the first and/or second source of DC thereby energizing these components. The device further includes a sensor, in electrical communication with the radio, for detecting AC availability. The radio has several modes. In a first mode, the radio is off regardless of whether the sensor detects availability of the AC. In a second mode, the radio is on when the sensor detects AC availability and the radio is off when the sensor determines that the AC is not available.

Abstract: A method, system, and computer program for predicting the failure of an electronic circuit. One embodiment of the invention monitors the current utilization, environment conditions, and operating conditions of the electronic circuit. A system manager is altered if the current utilization of the electronic circuit is outside a pass range at the measured environmental conditions and the measured operating conditions of the electronic circuit. The invention may also be configured such that if the electronic circuit fails, the electronic circuit is isolated from among a plurality of potentially failed electronic circuits using the measured current utilization, environment conditions, and operating conditions of the electronic circuit.

Abstract: A relaxation oscillator for a transponder capable of measuring one or more parameters (e.g., temperature, pressure) in an object and transmitting a data stream to an external reader/interrogator. The transponder typically operates in a passive mode, deriving its power from an RF interrogation signal received by an antenna system, but c=also operate in a battery-powered active mode. The transponder includes memory for storing measurements, calibration data programmable trim settings, transponder ID and the like. Measurement readings comprise counting oscillations of a measurement signal during a fixed time window. The measurement signal is generated by a relaxation oscillator driven by the alternating charging and discharging of measurement capacitors. wherein the capacitor charging rate is a function of current, and of capacitance. By using a mirror measurement current lo discharge the measurement capacitors, the discharge rate is made approximately equal to the charge rate.

Abstract: A user of a computer aided design (CAD) system graphically places fire alarm appliances, such as smoke detectors and sirens, in a drawing area. After elements are placed and physical paths are determined, a series of electrical circuit connections between alarm source elements and alarm appliance elements are determined. The electrical circuit connections define wire gauges and lengths passing through the physical paths. The wire types may be determined by predefined rules, and multiple wires may be placed in a single physical path. Subsequently, the CAD system performs electrical calculations associated with the alarm system. The electrical calculations may be based on a supervisory mode of operation as well as an alarm mode of operation. The resistance of wires in the alarm system may be based on a scaled wire length and/or a schematic (non-scaled) wire length. In one example, a backup battery capacity requirement is calculated.

Abstract: A lighting system contains at least one controllable first light (NL), which is connected to a first current supply (L, N), and at least one controllable emergency current light (SL), which is connected to a further emergency current supply (P, N), separate from the first current supply (L, N). All lights have respective control devices associated therewith, all control devices being connected to a common bus (D1, D2). A monitoring device (5) issues a monitoring signal corresponding to the condition of the first current supply (L, N) onto the bus (D1, D2), which monitoring signal is evaluated at least by the control device of the emergency current light (SL) for the recognition of a disruption and for activation of an emergency current operation.

Abstract: An electrically operated equipment with a sealed enclosure containing circuitry with an exterior visual indicator to show a state of operation of the equipment. The visual indicator is illuminated by a magnetic flux sensor also exterior to the equipment, the sensor inducing an electrical current from a sensed magnetic flux passing through a permeable wall of the enclosure. The magnetic flux is provided by a magnetic field generator within the enclosure. The generator is connected to the equipment to generate the field when the circuitry is operating correctly whereby the indicator shows a correct state of operation. The invention avoids the use of sealed orifices in the enclosure for conductors to pass to exterior LEDs or LEDs sealed within the enclosure and possible resultant leakage. The invention is useful for optical network units. The invention also includes a visual indicating device of multi-layer configuration and a method of visually indicating the operational state of circuitry.

Abstract: Detecting a signal disruption of an AC-signal by a DC-current in a powered networking system includes receiving an AC-signal from the networking system; analyzing the AC-signal based on a predetermined characteristic of the AC-signal and generating an analysis output; then comparing the analysis output with a predetermined reference source wherein the comparing detects the AC-signal disruption in the powered networking system.

Abstract: Normal hard-wired domestic burglar alarms have cables with six conductors extending between the alarm control panel and each event sensor (such as a PIR). Two of the conductors might provide current to a motion detector, two of the conductors might provide a circuit for a tamper switch, and two of the conductors might provide an indication of the motion detected by the motion detector. Wiring costs are reduced in the present invention by providing only two conductors which work to provide all of the functions of a six-conductor cable. To attach the two-conductor cable to a six-point terminal on the control panel, a special signal accessor and separator circuit is provided with six contacts to attach to the control panel terminals and two terminals for connecting to the conductor cable.

Abstract: An airflow blockage detection apparatus for a permanent split-capacitor single-phase cooling fan motor measures and compares electrical currents in main and auxiliary windings of the motor to detect airflow blockage. Main and auxiliary current sensors detect AC currents in the main and auxiliary windings, respectively, and a blockage detection circuit forms a difference between the detected currents. An airflow blockage alarm is activated when the current difference exceeds a specified setpoint indicative of abnormally low airflow.

Abstract: A method and apparatus for monitoring grounding of personnel and equipment in electrostatic discharge (ESD) sensitive areas. The device generates a low voltage alternating current control signal (60) which is applied to personnel (50) and equipment (350) being monitored. The device further includes signal conditioning (66) and detection means (70) to distinguish static charges from the control signal and transmit an alarm (72) upon detection of such static charge. The method encompasses the use of an alternating current control signal to detect static charge.

Abstract: A device representing a simple means of multiplying the functionality of wiring in point to point control circuits such that fault tolerant, fault reporting circuits can be constructed with less wire. The circuit can employ the wiring on a continuous basis by the use of AC and a series arrangement that may combine sensors and command loads on the same single wire loop. A bi-directional current detector with switchable impedance over each polarity can form the device. The detector may be equipped with an electrically isolated man-machine interface that communicates with light to achieve input-output functions. Command functions may be issued by changing the current level within the circuit over each polarity of current flow to series mounted remote loads that are polarized with diodes. The whole circuit can be in triplicate for high reliability and fault tolerance and use a common return wire.

Abstract: The instantaneous power consumption of an appliance is used to determine the status of the appliance, from which further actions may be taken. This invention is premised on the observation that most appliances have a characteristic power consumption pattern that can be used to determine the state of operation of the appliance. An electric coffee pot, for example, consumes high power substantially continuously during the brewing state, then reduces its power level, or power duration, or both, while keeping the pot warm, then terminates its power consumption when it is turned off. In like manner, the power consumption patterns of other appliances, such as toasters, washing machines, dryers, and so on may also be used to determine the state of each appliance. The communicated state may be used by a home-automation system to effect a variety of actions, including notifying the user, terminating the available power to the appliance, initiating an action by another appliance, and so on.

Abstract: An apparatus and method for compensating for a decreasing internal voltage that is generated from a higher external voltage. In response to the internal voltage decreasing in excess of a voltage margin, the amount by which the higher external voltage is reduced in generating the internal voltage is adjusted to raise the internal voltage.

Abstract: An electric power monitoring system includes a source monitor for measuring momentary power output of an electric source supplying electric power to a power distribution system having at least one electric load. The momentary power output is compared with a reference load capability for the electric source to determine the ability of the electric source to support additional load, and load capability data is transmitted based on the load capability. At least one load control receives the transmitted load capability data and controls the supply of power to the at least one corresponding electric load based on the load capability data.

Abstract: A fault diagnosis circuit of the present invention includes: LED indicating units 3a, 3b, and so forth; current detecting circuits R1 and Q1 for detecting a flowing current by flowing a short-time pulse of a current through the LED indicating units 3a, 3b, and so forth based on pulses generated by a pulse generating circuit 7; comparing circuits 8 and 9 for comparing a current value detected by the current detecting circuits R1 and Q1 with their respective threshold values to judge a disconnection and a short-circuit; and retaining circuits 10 and 11 for generating a signal and retaining the signal when the current value is judged as being smaller and larger than the respective threshold values as a result of comparisons by the corresponding comparing circuits 8 and 9. Thus, it is possible to indicate a fault in an LED indicating light to the outside while making the turning ON of an LED unperceivable.