Technical field

-The present invention relates to a construction system for a voltage and/or current sensor.

Prior art

-With reference to the preceding Italian patent applications IT-BO.2008.U.00079 and IT-BO.2008.U.00084, the entire content of which is incorporated herein by reference, these describe specific voltage and/or current sensors.

-These sensors carry out their function excellently, but, in some of the various embodiments, their construction is time-consuming and/or expensive if they are to be provided with passive voltage detectors.

Object of the invention

-The object of the present invention is to overcome the aforementioned drawbacks.

-The invention, which is characterized by the claims, resolves the problem of creating a construction system for a current and/or voltage sensor intended for use in combination with a busbar, in which said construction system extends along its longitudinal axis, thus forming a proximal and a distal portion with respect to said busbar, in which said construction system comprises a body formed from insulating material, a source electrode extending longitudinally along its longitudinal axis and having a proximal end connected to said busbar and a free distal end, a first screening element intended to form a screened chamber, and a first electrical field sensor placed in said screened chamber and spaced axially apart from the free end of said source electrode, and in which said construction system is characterized in that a second capacitive sensor, intended to detect the electrical field generated by said source electrode, is placed in the proximity of a proximal axial portion of said source electrode.

Brief description of the appended drawings -The following description of the construction system proposed by the present invention, in various practical embodiments, is provided by way of non-limiting example and makes reference to the appended drawings, in which: -Figure 1 shows the invention in a first practical embodiment; -Figure 2 shows the invention in a second practical embodiment; -Figure 3 shows the invention in a third practical embodiment.

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Description of the first embodiment - Figure 1 -With reference to Figure 1 , this shows a first embodiment of the construction system proposed by the present invention, in which said construction system 100 relates to a voltage sensor intended for use in combination with a busbar B, in which said construction system 100 extends longitudinally along its longitudinal axis Y-100, thus forming a proximal end 101 and a distal end 102 with respect to said busbar B. -Briefly, said construction system 100 comprises a containing body 110 formed from an insulating material, such as a solid dielectric material, a source electrode 120 extending longitudinally along its longitudinal axis Y-120 and having a proximal end 121 connected to said busbar B and a free distal end 122, a first screening element 130 (preferably made of metal mesh) intended to form a screened inner chamber 131 , a first electrical field sensor 140 placed in said screened chamber 131 and spaced axially apart from the free end 122 of said source electrode 120, and also placed in the proximity of a first proximal axial portion 123 of said source electrode 120, and a second capacitive sensor 150, described more fully below, intended to detect the electrical field generated by said source electrode 120, in which said capacitive sensor 150 is intended to transmit the corresponding signal by means of a lead 151 to a voltage indicator lamp 152, thus forming a passive detector of the presence of voltage.

-More specifically, in the present embodiment, said second capacitive sensor 150 comprises a first armature 154, preferably formed from an axial segment of said proximal axial portion 123 of said source electrode 120, and a second armature 155, preferably formed from a metal mesh element 155 placed in the proximity of, and spaced apart from, said first proximal axial portion 123, such as a ring of metal mesh rolled up to form a hollow cylinder and fitted around, and spaced apart from, said first proximal axial portion 123.

-Various mechanical solutions can be used to position said second capacitive sensor 150, for example fixing and fastening the sensor to said first screening element 130 by means of an element 160 of electrically insulating material which, as described more fully below, acts as a joint and spacer for the mechanical connection and fixing between said first screening element 130 and said second capacitive sensor 150,

-More specifically, in the present embodiment, said first screening element 130 has a proximal portion 132 shaped in the form of a first hollow cylinder extending axially and longitudinally with its open circular proximal end 133 facing the proximal end 101 of the construction system 100, and said second armature 155 comprises a second hollow cylinder which also extends axially and longitudinally with its open circular distal end 156 facing the distal end 102 and its opposing open circular proximal end 157 facing the proximal end 101. -With this construction, said joint and spacer 160 can preferably take the form of a third hollow cylinder 160 whose shell has an H-shaped cross section, in which the distal branches 161 and 162 of said H-shape are intended to be connected axially to the proximal edge of the proximal end 133 of the first hollow cylinder 132, and the proximal branches 163 and 164 of the H-shape are intended to be connected axially to the circular edge of the distal end 156 of the second hollow cylinder 155.

-With this technical solution, the source electrode 120 can pass freely through the axial hole of said second hollow cylinder 155 and through the axial hole of said third hollow cylinder 160 and then through the open end 133 of said first hollow cylinder 132, said first 132 and said second 155 hollow cylinder having an inside diameter such that a minimum space is formed between said source electrode 120 and the inner part of said hollow cylinders 132 and 155 such that the dielectric strength of the dielectric insulating material is not exceeded and consequently the required degree of insulation is achieved, while the insulating properties of the dielectric medium are maintained and preserved over time.

-In this context, it is clear that other types of insulating joints can be used in place of the joint 160, and that the second capacitor armature 155 can be embedded in the correct position in the body 110 of dielectric material by using other supporting and positioning systems, in order to position said second hollow cylinder 155 so that it is axially spaced apart from the proximal open end 133 of said first hollow cylinder 132 and is placed around the source electrode 120, without departure from the inventive concepts protected by the present invention.

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Description of the second embodiment - Figure 2

-With reference to Figure 2, this shows a second embodiment of the construction system proposed by the present invention.

-In this embodiment, the second capacitor armature, indicated here by 255, is also provided with branches 270 intended to support other electrical members, such as a screened coil 280 of the Rogowski type.

-In this context, said branches 270 can be made from electrically insulating material or from electrically conductive material, according to their use.

* * * * Description of the third embodiment - Figure 3

-With reference to Figure 3, this shows a third embodiment of the construction system proposed by the present invention.

-In this embodiment, said metallic element or second capacitor armature, indicated here by 355, is supported and positioned by means of a bar 370 having a first end 371 fixed to said capacitor armature 355 and an opposing second end portion 372 fixed to a base 335 of the screening element, indicated here by 330.

-By way of example, said bar 370 is preferably made of conductive material and its second end portion 372 is provided with a flange 373 for connecting and fastening said second end portion 372 in a bush 374 of insulating material which is fixed to the base 335.

-The distal end of said bar 370 carries a lead 351 for transmitting the corresponding signal to a voltage indicator lamp 352, thus forming a passive detector of the presence of voltage.

* * * * -The above description of the construction system is provided solely by way of non-limiting example, and clearly, therefore, said construction system can be modified or varied in any way suggested by experience and/or its use or application within the scope of the following claims. -The following claims consequently also form an integral part of the above description.