4379results about "Current measurements only" patented technology

A system for managing loads and detecting outages over electric power lines that comprises wireless temperature sensors which are attached to bare conductors of the electric power line(s), at line junctions or lines' splitting points, for sensing temperatures generated by the currents flow in the conductors. The system also includes a Current Measurement Units (CMU) for wirelessly reading the temperature sensed by the sensors, to allow cheap, rapid and easy RMS currents measurements on power lines at any voltage levels, by using temperature into current conversion formulas and tables.

A current sensor is described that uses a plurality of magnetic field sensors positioned around a current carrying conductor. The sensor can be hinged to allow clamping to a conductor. The current sensor provides high measurement accuracy for both DC and AC currents, and is substantially immune to the effects of temperature, conductor position, nearby current carrying conductors and aging.

A circuit arrangement for detecting a load current through a load includes a main transistor, a sensing transistor through which a load current flows that is a measure of the load current flowing through the main transistor, a means of resistance which is connected in series with the load path of the sensing transistor, a current source which is connected to a node which is arranged between the sensing transistor and the means of resistance, and a detector which detects the load current flowing through the main transistor by measuring the voltage across the means of resistance.

One embodiment of the present invention provides an apparatus that measures the average-output-current produced by a switching regulator within an electronic device. The apparatus includes current-sensing-circuitry coupled to a switching field-effect-transistor (FET) within the switching regulator, wherein the current-sensing-circuitry is configured to bypass a small sense current from the conducting current of the switching-FET according to a sense ratio, wherein the conducting current is controlled by a control signal for the switching regulator. The apparatus also includes a current-to-voltage-converter coupled to the current-sensing-circuitry which is configured to convert the sense current into a sense voltage. The apparatus further includes voltage-averaging-circuitry which is configured to produce an average-sense-voltage from the sense voltage. This sense voltage is coupled to the input of the voltage-average-circuitry through a switch, which is gated by the control signal. The average-output-current of the switching regulator is indicated by the average-sense-voltage.

The invention relates to a device for measuring current in an inductor, which device is intended to be connected in parallel with said inductor, comprising two terminals A and B. The device comprises: a network in parallel with the inductor and connected to the terminals A and B having a resistor R2 in series with a resistor R1 in parallel with a capacitor C1; a voltage offset circuit having a DC voltage generator E connected in parallel with an offset resistor (Roffset) in series with two resistors in parallel R3 and R4, the positive pole of this voltage source being connected to terminal B of the inductor; a temperature compensation circuit comprising a current source controlled as a function of the temperature, one of the two terminals of the current source being connected to the negative pole of the generator E, the other terminal of the current source being connected to different points of the measurement device according to the direction of variation of the current of the source as a function of the temperature. The measurement of voltage Vmes, the image of the current I in the inductor 12, is performed between the common point between the resistors R1, R2 of the network and the common point between the offset resistor and the two resistors R3 and R4.

A method and system for programming, calibrating and driving a light emitting device display is provided. The system may include extracting a time dependent parameter of a pixel for calibration.

Apparatus and method for measuring current drain and reporting power consumption using current transformer with primary windings made of low ohmic alloy, enabling the use of the secondary coil to power the sensing and reporting circuits eliminating the power wasted by AC-DC power adaptors used for the current sensors. The saving is substantial as the current sensors will not drain a current when the AC outlets are disconnected from a load or when the load is switched off. The apparatus using low ohmic alloy is extended to the structuring of terminals, including power pins, power sockets and combinations to provide a low ohmic sensing elements in AC plugs, outlets, adaptors and extension cables with multi outlets, dissipating the heat from the sensing elements by the plugs and the larger metal heat dissipation.

A low-cost and high-precision current sensing device and methods for use and manufacturing. In one embodiment, the current sensing apparatus comprises a Rogowski-type coil which is manufactured in segments so as to facilitate the manufacturing process. In an exemplary embodiment, the current sensing apparatus segments comprise a number of bobbin elements that are wound and subsequently formed into complex geometric shapes such as torus-like shapes. In an alternative embodiment, bonded windings are utilized which allow the segments to be formed without a bobbin or former. In yet another alternative embodiment, the aforementioned current sensing devices are stacked in groups of two or more. Methods of manufacturing and using the aforementioned current sensing apparatus are also disclosed.

Circuits for sensing current levels within an apparatus are disclosed. In specific cases, a constant voltage power supply is used to power an LED lighting apparatus in which there are uncertainties within the forward voltages of the LEDs, which in turn creates uncertainty with respect to the current level flowing through the LEDs. To manage these uncertainties, the current flowing through the LEDs is measured by determining a voltage level across a known resistor and calculating the current level. To prevent the known resistor from causing a significant reduction in the efficiency of the overall light engine, the circuit includes one or more transistors in parallel with the known resistor to reduce the effective resistance in the LED circuit during times that the current is not being sensed.

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.

A switched mode power can use a digital controller to control the switching of the at least one switch of the switched mode power supply. The current through the power inductor can be estimated using a self-tuning digital current estimator.

An electric current detector is provided wherein loose arrangement of conductor 6 in opening 5 provides an air gap between the conductor 6 and plastic package 4 in opening 5 to prevent close contact of conductor 6 to plastic package 4. When heat and heat stress are produced in conductor 6 by a large electric current flowing through conductor 6 during measurement, air gap surely prevents heat and heat stress from traveling to Hall effect sensor 2 and plastic package 4 while a part of heat in conductor 6 is radiated into air in opening 5. Thus, the loose arrangement of conductor 6 can restrict or reduce deterioration of electric property in Hall sensor 2 and degradation of mechanical property in plastic package 4 by heat and heat stress in conductor 6. Also, the loose arrangement ensures and facilitates attachment of the detector 1 in position on a surface of a substrate, and enables to maintain conductor 6 at the same level as lead terminals 3 of the detector.

A humidifier includes a tub configured to contain a supply of water and a heater including a first polymer film having an electrically conductive circuit provided upon a surface. The first polymer film is electrically insulating and the tub is formed of molded resin and the heater is molded at least partially within the resin. A respiratory apparatus for delivering a flow of breathable gas to a patient includes the humidifier. A method of humidifying a flow of pressurized breathable gas includes passing the flow of pressurized breathable gas over a supply of water contained in a tub. The tub is formed of molded resin and a heater including a first polymer film having an electrically conductive circuit on a first surface is molded at least partially within the resin.

A method of outputting to a user an indication of the usage of a utility, the method comprising: obtaining data indicating, for each of a plurality of appliances, a respective current level of usage of the utility by that appliance; for each of a plurality of appliance categories, using the obtained data to calculate a respective current total level of usage of the utility by appliances belonging to that appliance category; and outputting an indication of the calculated current total level of usage of the utility for at least one of the plurality of appliance categories.

Apparatus and methods are provided for the measurement of a power factor at points of interest, such as circuit breakers, machines, and the like. Accordingly, means are provided for measurement of a power factor for each electrical sub-network that is controlled by a circuit breaker. Each apparatus is enabled to communicate its respective data, in an environment of a plurality of such apparatuses, to a management unit which is enabled to provide finer granularity power factor profiles.

A method and system is provided for determining at least one operating characteristic associated with an inductor in a power converter system. The operating characteristic may be current through the inductor. The power converter system may be of the type used in a hybrid electric vehicle (HEV) to convert electric power from a high-voltage traction battery to drive an electric motor and/or a generator in the HEV.

Some embodiments can concern a method of using a power consumption measurement device. The power consumption measurement device can be mechanically coupled to a surface of a circuit breaker box overlying at least part of one or more main electrical supply conductors for an electrical power infrastructure of a structure. The method can include: determining one or more first magnetic field readings from the one or more main electrical supply conductors using one or more sensors in the power consumption measurement device; after determining the one or more first magnetic field readings, electrically coupling a first calibration load to the electrical power infrastructure; while the first calibration load remains electrically coupled to the electrical power infrastructure, determining one or more second magnetic field readings from the one or more main electrical supply conductors using the one or more sensors in the power consumption measurement device; calibrating the power consumption measurement device using at least in part the one or more first magnetic field readings and the one or more second magnetic field readings, after calibrating the power consumption measurement device, determining one or more third magnetic field readings from the one or more main electrical supply conductors using the one or more sensors in the power consumption measurement device; and determining an electrical power used by the electrical power infrastructure of the structure using at least the one or more third magnetic field readings and the one or more calibration coefficients. Calibrating the power consumption measurement device can include determining one or more first calibration coefficients for the power consumption measurement device using at least in part the one or more first magnetic field readings and the one or more second magnetic field readings. Other embodiments are disclosed.

A power MOSFET, comprising main and current mirror MOSFETS, has a current sense resistance coupled between its mirror and source terminals and a monitoring circuit responsive to a first voltage dependent upon current through the current sense resistance. The circuit arrangement includes a circuit that determines a second voltage, different from the first voltage, of a terminal of the current mirror MOSFET, and a circuit arranged to determine current of the power MOSFET in dependence upon the first and second voltages. The second voltage can be the voltage at the drain terminal, or the voltage at the mirror terminal with switching of the current sense resistance or a current that it passes. It can alternatively be determined by a control circuit to be a desired fraction of the drain voltage.

The invention relates to a gas insulated electrical equipment partial discharge multi-sensor combined monitoring experiment device comprising a power frequency AC power supply system, a gas discharge chamber, at least four artificial insulation defect models and a multi-sensor combined detection system which comprises four parts of a pulse current method sensor detection system, an ultrahigh frequency sensor detection system, a gas chromatography mass spectrometric detection sensor detection system and a fluorescence fiber sensor detection system. Partial discharge of an SF6 gas insulated electrical equipment typical defect under different air pressure, different electric field distribution and different gas types of the condition of power frequency alternating current can be simulated, electrical, optical, ultrahigh frequency and gas component multi-source information of partial discharge of equipment is acquired, and effective characteristic quantity of the most mechanism of PD signals with the closest insulation connection can be mined so that a simple and feasible method and experiment platform are provided for the experimental study of construction of a comprehensive and integrated complete SF6 gas insulated electrical equipment insulation state information base.

A high side current monitor circuit includes an op amp which is coupled across a sensing element which carries a current I_sense and develops a shunt voltage V_sense. A feedback transistor driven by the op amp output conducts an output current I_out through a resistor to a current output node necessary to make the op amp inputs equal, such that I_out is proportional to I_sense. I_out is conducted through a resistor to generate a ground-referred voltage proportional to V_sense. When the common mode voltage of V_sense is greater than the op amp's breakdown voltage, a discrete transistor is connected between the current output node and ground to stand off the voltage across the amp. The monitor circuit is arranged such that it can be powered with a limited fraction of the common mode voltage when used with a discrete transistor, and is self-biased when used without a discrete transistor.