FR2687831A1 - TORE-SHAPED TRANSFORMER FOR DIFFERENTIAL SENSOR OPERATING IN CLASS A. - Google Patents

Abstract

Toroidal transformer (1) for Class A differential sensor. The secondary winding (6) is only wound on one sector of the first insulating case (5), of angle (A) for example of the order of 180 degrees. The second insulating case (7) is therefore made up of two nested half-sectors (7A, 7B), which leaves a free part (5S) of the first insulating case (5) around which the primary winding is then wound ( SP, SN). The overall size of the transformer is thus reduced.

Description

TORE-SHAPED TRANSFORMER FOR SENSOR

  DIFFERENTIAL OPERATING IN CLASS A

  The present invention relates to a toroidal transformer for a differential sensor operating in Class A, that is to say a differential sensor sensitive to currents.

  straightened or continuous components.

  A Class A differential sensor toroid is a transformer specially designed for, unlike the most common transformers, to be sensitive to continuous components or rectified currents. Such a transformer is conventionally composed, successively from the inside to the outside of a transformer. annular toroidal magnetic core: a first insulating case, annular in shape, which surrounds, and therefore protects against shocks, the magnetic core; a secondary wire winding uniformly distributed over 360 degrees and wound around this first insulating housing; and

  * a second annular insulating housing, in two half

  shells, which completely surrounds this secondary wire winding and thus serves as an envelope, or shell, annular protection for

1 set.

  Finally, this transformer comprises the primary wire winding, which generally comprises the phase wire (s) and the neutral wire of the electric power supply line, and

  which passes into the central orifice of the first annular housing.

  As the case may be, the primary wire winding passes either directly into this central orifice without creating turns, or passes on the contrary through it by performing one or more turns around the

second insulating case.

  In the event of a ground wire or a neutral wire leakage, the secondary winding is the seat of a voltage

  induced that allows to recognize this defect.

  This need to wind the primary winding around the second housing causes a relatively large size for this transformer, which penalizes the differential sensor for some implantations, and in particular often offers little

latitude to mount in caliber.

  The invention aims to remedy this disadvantage. It relates to a toroidal transformer for a differential sensor operating in Class A, this transformer comprising on the one hand an annular magnetic core which is surrounded by a first form-insulating casing. IEC 60050 - International Electrotechnical Vocabulary - Details for IEV number 815-21-21 Superconductivity / Circuits (PCT / FR) / R04-2 / 00. A ring forming a passage for the primary winding, for example constituted by at least one turn of at least one phase wire and / or the neutral wire of an electric power supply line, and further comprising a secondary winding which is wound around this first insulating casing and which is itself protected by a second insulating casing which surrounds it according to the invention, and in order to allow a reduction of the total encumbrance of this transformer: secondary winding is distributed over an angular sector less than 3600, and in any case sufficient to leave, in the sector thus remaining unwound, the place for the primary winding; the second insulating housing is formed in the form of angular sector corresponding to that of this secondary winding; and the primary winding is then wound around the first insulating housing and in the area left free by the second

insulating case.

  According to an advantageous embodiment, the secondary winding, and the second insulating housing, are distributed over a

  angular sector of the order of 180 degrees.

  In any case, the invention will be well understood, and its advantages and other characteristics will emerge, when

  following description of a nonlimiting example of embodiment of a

  Class A differential sensor toroidal transformer, with reference to the accompanying schematic drawing in which: Figure 1 is an overall perspective view of this transformer; Figure 2 is a side view; Figure 3 is a sectional view along III-III of Figure 2; and

  Figure 4 is an exploded perspective view.

  Referring to all the figures, it is a transformer 1 torus-shaped differential sensor operating in Class A, such a transformer being more

  simply called "Tore Class A" in business language.

  In this example, it is a single phase differential sensor and the toroidal transformer 1 is traversed by the phase wire and the neutral wire respectively constituting the primary winding of phase 2 and the primary winding of

neutral 3.

  It comprises a magnetic core 4, visible in FIGS. 3 and 4, in the form of an annular torus with a rectangular section, this magnetic core 4 being wrapped in a first protective insulating housing 5, of a shape corresponding to that of the core 4, which is composed of two interlocked half-shells, SA and B. The secondary winding 6 consists of a winding with a large number of turns which, according to the invention, is not

  distributed on an angular sector A of the order of one half

  circle In the case shown, this angular sector A

  extends over a little over 180 degrees.

  A second insulating casing 7, in the form of a sector of the same angle A as the secondary winding 6, is provided to serve as a protective envelope for this winding 6 It consists of two nestable half-sectors 7 A and 7 B and its shape correspond to

that of winding 6.

  The secondary winding 6 has rectangular turns, wound on the first housing 5, but this winding is only performed on the first angular sector A. Under these conditions, it can be seen that the primary windings 2 and 3, comprising in this example a coil SP of the phase wire and a turn SN of the neutral wire, can then be wound on the second portion 5 S thus remaining apparent of the first insulating housing 5, which provides a saving of space

  not negligible for this transformer.

  Preferably, the two turns, SP and SN, of the phase wire and the neutral wire are wound around the free remaining portion 5 S of the housing 5 so as to bear against the wafer 8 of the second housing 7, which makes it possible to maintain this

  last in position and strengthen the strength of the whole.

  As goes without saying, the invention is not limited to the example of embodiment which has just been described. For example, the angle A could be much greater than 180 degrees instead of being neighbor, provided that it leaves free a sector 5 S sufficient to allow the winding of the primary turns, such as the SP and SN turns represented, around

  the portion remaining apparent of the first insulating housing 5.

Claims (3)

  1 toroidal transformer used in a differential sensor operating in Class A, and comprising: an annular magnetic core (4) surrounded by a first annular insulating housing (5) on which a primary phase winding (2) is arranged and a primary neutral winding (3), a secondary winding (6) wound around the first insulating casing (5), and a second insulating casing (7) surrounding the secondary winding (6), characterized in that the secondary winding (6) is distributed on the first housing (5) along a first angular sector (A) less than 3600, that the primary windings (2,3) are wound around the first housing (5) insulating along a second complementary sector (55) left free, and that the second housing (7) insulating is arranged in angular sector of shape conjugate to the first sector (A).   Transformer according to Claim 1, characterized in that the first angular sector (A) of the secondary winding (6)   extends around 180 degrees.   Transformer according to one of claims 1 or 2,   characterized in that the primary phase (2) and neutral (3) windings bear against the slices (8)   ends of the second housing (7) insulating.