Clamp-type measuring device for small alternating-direct current

Abstract

The invention discloses a clamp-type measuring device for small alternating-direct current. The device comprises a sensing head, a modulation transformer, a band pass filter, a phase-sensitive demodulator, a direct-current amplifier, a power amplifier, an alternating-current filter amplifier, a coupling capacitor and a standard resistor, the sensing head comprises upper and lower semicircular U-shaped detection iron cores, the upper semicircular U-shaped detection iron core comprises first and second semicircular detection iron cores, the lower semicircular U-shaped detection iron core comprises third and fourth semicircular detection iron cores, and the first, second, third and fourth semicircular detection iron cores are wound with first, second, third and fourth modulation detection windings respectively; the outer faces of the upper and lower semicircular U-shaped detection iron cores are wound with fifth and sixth alternating-current detection windings respectively. The upper andlower semicircular U-shaped detection iron cores after being assembled are integrally put into a half cavity of an annular magnetic shielding iron core composed of two semicircular magnetic shieldingiron cores, and a feedback winding is wound outside the annular shielding iron core. The modulation detection windings and the alternating-current detection windings respectively measure direct-current and alternating-current components of measured current so as to realize measuring of small alternating-direct current.

Description

technical field [0001] The invention belongs to current measuring equipment in the electrical technology, in particular to a clamp-type measuring device for small AC and DC currents. Background technique [0002] Application No. 201510854478.5 "A small DC current clamp-type measuring device", aiming at the problem of insufficient sensitivity and precision when the existing clamp-type DC current measuring device is used for the measurement of small DC currents in industrial sites, the sensor head is proposed to be divided into upper and lower halves The clamp-type structure of the ring is made of permalloy material to form the first half-ring detection core and the second half-ring detection core of the upper half-ring U-shaped detection core, and the third half of the lower half-ring U-shaped detection core. The ring detection iron core and the fourth half-ring detection iron core, the upper and lower half rings form a closed U-shaped detection iron core structure, which not...

AI Technical Summary

Problems solved by technology

[0003] The invention provides a clamp-type measuring device for small AC and DC currents, which solves the problem that the existing sensor heads and measuring devices can only measure small DC currents, and is used for small AC and DC currents with a simple and stable structure. Measurement

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