RU207403U1 - Current sensor - Google Patents

Abstract

The utility model relates to the field of electrical engineering and can be used to measure the magnitude of the current. The current sensor consists of a conductive power bus installed on it through the insulating material of a board with a Hall sensing element, a magnetic shield having an octagon-shaped cross-section with parallel chords in the upper and the bottom sides, and the housing, which protects the sensor from external influences. The proposed design solution allows the measurement of current in conditions of increased exposure to external magnetic fields.

Description

The utility model relates to the field of electrical engineering and can be used to measure the magnitude of the current.

The current sensor consists of a conductive power bus installed on it through the insulating material of a board with a Hall sensing element, a magnetic shield having an octagonal cross-section with parallel chords in the upper and lower sides, and a housing that protects the sensor from external influences.

Known current sensor [1, 2] based on the Hall effect. An isolated current sensor containing a Hall sensing element with a magnetic field concentrator is built using direct amplification technology. A copper conductive conductor is located near the surface of the crystal of the sensitive element. The applied current flowing through the copper conductor generates a magnetic field, which is sensed by the integrated Hall sensor and converted into a corresponding voltage.

The disadvantages of the known technical solution is the high sensitivity to external magnetic fields from other conductors and coils with current, as well as from permanent magnets.

The closest is the constructive solution of an open-type current sensor that uses the Hall effect for direct registration of the flowing current and output of the converted Hall voltage [3, 4]. A single-axis integral current sensor is used as a sensing element. The sensing element with a plate-type magnetic core is installed above the busbar in a housing that is attached directly to the busbar by means of a threaded fastener. Depending on the location of the sensing element above the conductor, sensors can be created for both relatively small and very large measured currents.

The disadvantages of this solution are (as in the previous solution) high sensitivity to external magnetic fields from other conductors and coils with current and from permanent magnets.

The objective of the proposed solution is non-contact current measurement with low sensitivity to external magnetic fields.

The technical result is to increase the resistance of the current sensor to external magnetic fields.

The specified technical result is achieved by the fact that the proposed solution uses a magnetic screen having a cross-section in the form of an octagon with parallel chords in the upper and lower sides, thereby significantly reducing the effect of external magnetic fields on the sensitive element of the sensor.

FIG. 1 shows the inventive current sensor, consisting of a conductive power bus 1, fixed on it through an insulating material 2 of a printed circuit board 3 with a Hall sensing element 4, a magnetic screen having an octagon-shaped cross-section with parallel chords in the upper and lower sides 5, and a housing 6.

The current sensor works as follows. When current flows through bus 1, a magnetic flux is formed around it. Hall sensor 4, mounted on the board 3 and fixed on the bus 1 through the insulating material 2 at a fixed distance from the bus 1, converts the received magnetic flux into electrical signals, which are converted to the required levels using the board components. The Hall sensor is magnetically shielded to protect against external magnetic fields. Due to its octagonal cross-section, the inner corners of the magnetic shield have a turn of more than 90 degrees, which significantly reduces the effect of external magnetic fields on the sensitive element inside the shield. Octagon chords at the top and bottom provide enhanced protection against external magnetic fields in the projections of the maximum sensitivity of the sensor.

The current sensor is protected from external influences by a housing 5.

The technical advantage of this solution is to reduce the sensitivity to external magnetic fields due to the use of a magnetic shield having an octagon-shaped cross-section with parallel chords in the upper and lower sides, and the housing.

Literature sources

1. Makita Yo. Current sensors with additional intelligent functions / Y. Makita, S. Rollier // Power electronics. - 2014. - No. 1. - with. 40-43.

2. Utkin A. Current sensors ACS750 firm Allegro: theory and practice // Modern electronics. - 2004. - No. 12. - S. 18-21.

3. Semykina I.Yu. Ensuring the accuracy of current sensors with an open non-ring magnetic circuit / I.Yu. Semykina, A.V. Grigoriev // Bulletin of the Kuzbass State Technical University. - 2015. - No. 5 - p. 103-110.

4. Patent RU 2531040 C1 Insulated current sensor / Zavyalov VM, Semykina I.Yu., Grigoriev AV, Tatarinov DE, Merzlyakova EA. Published: 20.10.2014 Bul. No. 29.

Claims (1)

The current sensor consists of a conductive power bus installed on it through the insulating material of a board with a Hall sensing element, a magnetic shield having an octagonal cross-section with parallel chords in the upper and lower sides, and a housing that protects the sensor from external influences.

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