Vacuumschmelze Gmbh & Company Kg

Vacuumschmelze Gmbh

Other

Friedrich Lenhard

Norbert Preusse

Stefan Sch&auml;fer

Paul Mourick

Sebastian Kudimow

Stefan Schäfer

Stefan Schaefer

The current sensor arrangement according to the compensation principle has a primary conductor, designed to generate a primary magnetic field dependent on a current to be measured flowing through it, a first secondary winding, designed to generate a first secondary magnetic field dependent on a first compensation current flowing through said winding, a second secondary winding designed to generate a second secondary magnetic field dependent on a second compensation current flowing through said winding, a magnetic field sensor designed to generate a measurement signal that represents a magnetic field detected by it; a magnetic core of soft magnetic material designed and arranged to magnetically interconnect a primary conductor, a first seconding winding, a second secondary winding, and a magnetic field sensor; a first evaluation circuit, downstream from the magnetic field sensor and upstream from the first secondary winding, and a second evaluation circuit, upstream from the second secondary winding.

Compensation current sensor arrangement

A current sensor comprising a primary conductor for conducting a current that is to be measured, at least two magnetic field probes for measuring magnetic fields, and a magnetic core, which has a closed ring structure having three or more corners that encloses the primary conductor, wherein each magnetic field probe is arranged on the magnetic core or in recesses in the magnetic core.

Current sensor arrangement

A measuring method for measuring currents with a large dynamic range by means of a magnetic measuring module has the steps of switching into a high-current mode when a current threshold value is exceeded, and switching into a low-current mode otherwise, wherein the low-current mode has the following steps:&#x2014;Feeding a first current pulse to a compensation coil, which drives a magnetic core in a first direction until magnetic saturation occurs,&#x2014;measuring a first primary current value Iafter the current pulse is disconnected,&#x2014;feeding a second current pulse to the compensation coil, which drives the magnetic core in a counter second direction until magnetic saturation occurs,&#x2014;measuring a second primary current value Iafter the second current pulse is disconnected,&#x2014;determining the corrected primary current value subsequently as an average value I=(I+I)/2 from the first and the second primary current values.

Measuring method and measuring arrangement for measuring currents with a large dynamic range

Addressed is a current transformer comprising a primary conductor, a secondary winding and a soft-magnetic core, whereby the primary conductor and secondary winding are electrically insulated from one another and are magnetically intercoupled via the core. In addition, a current to be detected is injected into the primary conductor, and a compensating current is injected into the secondary winding. An additional conductor is provided which is electrically connected in parallel to the primary winding, and which is situated in the area of the core at which a flux rise occurs, whereby the flux rise is at least partially compensated for by the flux elicited by the current flowing in the additional conductor.

Current transformer for a compensating current sensor

The invention relates to a compensation current sensor, comprising a magnet core (M ), with a first section around which a secondary winding (S ) is wound. A magnetic field probe (MS ) is arranged in the vicinity of the secondary winding (S ). A primary winding is magnetically coupled with the secondary winding (S ). A metal screen (A ) is provided at a distance from the magnet core (M ). On the plane, on which the magnet core (M ) lies, the shield (A ) surrounds the magnet core (M ), with the exception of a side opening, whereby part of the opening is in the vicinity of the magnetic field probe (MS ) and arranged and configured such that magnetic flux which passes through the shield (A ), partially passes through the magnetic field probe (MS ).

Compensation current sensor

A current sensor ( ) is provided with low-pass filters ( and ) for stabilizing the pulse-duration modulated compensation signal. The current sensor is also provided with an additional RC element ( ). Furthermore, a limiting means consisting of Zener diodes ( ) and an ohmic resistance ( ) is provided for suppressing fast current transients.

Current sensor working in accordance with the compensation principle

Magnet core

Current sensor with a magnetic core (,) on which, besides a primary winding (,) in which the current to be measured (i) flows, at least one secondary winding (,) is wound, into which winding an alternating current that is generated by a generator circuit (,to,to,) is fed, said current saturating the magnetic core (,) in alternating fashion in at least one direction, whereby the generator circuit is self-running, whereby the polarity of the alternating current generated by the generator circuit (,to,to,) alternates depending on the current flowing in the secondary winding (,) and on at least one threshold value for this current.

Current sensor with self-oscillating generator circuit

Current sensor according to the compensation principle, in which the magnetic field produced by a primary winding (,) through which the current to be measured flows is compensated by the compensation current in a secondary winding (,), and in which for the controlling of the compensation current at least one sensor (,) that is influenced by the magnetic field acquires deviations from the zero current and supplies this measurement value to a driver circuit (,) for the production of the compensation current, whereby at the output of the driver circuit (,) the secondary winding (,) is connected in series to a terminating resistance (,), a voltage (Ua) that is proportional to the current to be measured is present at the terminating resistance (,), two amplifiers (,) in a bridge circuit, which are controlled by the measurement value and which supply output signals in phase opposition to one another, are used as a driver circuit (,), and the series circuit of the secondary winding (,) and terminating resistance (,) is connected between the outputs of the amplifiers.

Current sensor according to the compensation principle

A current-compensated current sensor for hysteresis-dependent and temperature-dependent measurement of even relatively large currents at different frequencies, includes a soft-magnetic magnet core having a flat magnetization loop. The sensor thus also permits rapid changes in a primary current to be measured.

Current-compensated current sensor for hysteresis-independent and

A current sensor operating according to the compensation thereon which is particularly suited for acquiring high currents has a secondary winding of the current transformer is divided into at least two sub-windings that are supplied by different amplifiers in an amplifier arrangement. This results in symmetrical loading of the supply voltage so that twice as high a compensation current is enabled given the same internal resistance of the sub-windings and same resistance of the terminating resistor as in known current sensors of this type.

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Hanau, Germany

Friedrich Lenhard