JP2018124196A - Electronic instrument and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the number of components by allowing an assembly of a through-type current transformer and a current terminal to a housing to be easy.SOLUTION: When through-type current transformers 18, 19 are arranged on a front surface side of a base 16, and through-holes 27, 30 of the through-type current transformers 18, 19 and terminal holes of the base 16 are put into a positional displacement state so that the through-holes 27, 30 and the terminal holes are inserted with current terminals 14, 15 to be guided to the back side of the base 16, the through-type current transformers 18, 19 are made to slide so as to be stored in the front surface side of the base 16 after inserting current terminals 14, 15 into the through holes 27, 30 of the through-type current transformers 18, 19 and the terminal holes of the base 16 in a state that the through-type current transformers 18, 19 extend beyond the base 16 due to a positioning between the through holes 27, 30 of the through-type current transformers 18, 19 and the terminal holes of the base 16, and cutaway portions 28, 31 formed on the current terminals 14, 15 are fitted to inner peripheral parts 29, 32 of the through-type current transformers 18, 19.SELECTED DRAWING: Figure 12

Description

  The present invention relates to an electronic meter incorporated in an electronic watt-hour meter that measures and displays the amount of power used by a power consumer such as a general household, and a method for manufacturing the same.

  For example, an electronic watt-hour meter is known as a low-voltage watt-hour meter that measures and displays the amount of power used by a power consumer such as a general household (see, for example, Patent Document 1).

  This type of electronic watt-hour meter is a terminal block having a power supply side terminal and a load side terminal to which a distribution line is connected while a communication terminal unit, a watt-hour meter unit and a switch unit are assembled on the upper part of the meter body Has a structure attached to the lower part of the instrument body.

  The watt-hour meter unit incorporated in the electronic watt-hour meter incorporates a measurement circuit that measures the amount of power supplied from the power source to the load via the distribution line.

  The measurement circuit includes a voltage detection unit that detects a voltage applied to the power supply side terminal, a current detection unit that detects a current flowing between the power supply side terminal and the load side terminal, and a voltage and current detection detected by the voltage detection unit. And a power calculation unit that measures the amount of power from the current detected by the unit.

  The current detection unit includes, for example, an instrument current transformer having a structure in which a core on which a coil is mounted is molded with an exterior resin material or a core on which a coil is mounted is stored in an exterior case. As this instrument current transformer, there is a cylindrical through-type current transformer.

  The watt-hour meter unit has a display window for displaying the amount of power on the front side of the casing, and has a structure in which a voltage terminal and a current terminal are led out on the rear side of the casing (FIG. 5 of Patent Document 1). reference). In the watt-hour meter unit, the current detection unit described above detects the current flowing through the current terminal with the through-type current transformer by inserting the current terminal through the through-hole of the through-type current transformer housed in the housing. Is configured.

JP 2006-170787 A

  By the way, the above-described watt-hour meter unit uses a current terminal led to the back side of the housing as a blade-shaped contact, and inserts it into a blade-receiving contact provided on the meter body of the electronic watt-hour meter. It is assembled to the main body.

  In the electronic watt-hour meter, the position and size of the blade contact of the meter body where the watt-hour unit is assembled are defined. Since there is such a regulation, the watt-hour meter unit is restricted by the position and dimensions (blade width) of the current terminal with respect to the housing.

  On the other hand, as described above, the watt-hour meter unit allows a current terminal to be inserted into a through hole of a through-type current transformer housed in a housing, and the current terminal to be inserted through a terminal hole provided in the housing. It has a structure derived from the back side of the housing.

  If there are restrictions as described above, the through hole of the through-type current transformer housed in the housing and the terminal hole of the housing through which the current terminal is inserted may be relatively displaced. Due to the relative displacement between the through hole of this through-type current transformer and the terminal hole of the housing, the assembly is assembled to the housing after assembling the through-type current transformer and current terminal in advance. In addition, a through current transformer and a current terminal must be assembled to the housing after the current terminal has a divided structure.

  As a result, the assembly of the through-type current transformer and the current terminal with respect to the housing becomes complicated, and the number of parts of the current terminal increases. For this reason, the through current transformer and the current terminal must be manually assembled to the housing by an operator, and the ease of assembling the through current transformer and the current terminal to the housing can be improved. It was difficult.

  Therefore, the present invention has been proposed in view of the above-described improvements, and the object is to simplify the assembly of the through-type current transformer and the current terminal to the housing and reduce the number of parts. It is an object of the present invention to provide an electronic instrument capable of easily assembling and a manufacturing method thereof.

  An electronic instrument according to the present invention includes a base that forms a casing with a cover, a through-type current transformer disposed on the front side of the base, a through-hole of the through-type current transformer, and a terminal hole of the base And a current terminal that is inserted into the through hole and the terminal hole and led out to the back side of the base.

  As a technical means for achieving the above-described object, the current terminal in the electronic instrument according to the present invention is a penetration that protrudes from the base by aligning the through-hole of the through-type current transformer and the terminal hole of the base. It has a notch into which the inner peripheral part of a penetration type current transformer fits by sliding a type current transformer.

  In the electronic instrument according to the present invention, even if the through-hole of the through-type current transformer and the terminal hole of the base are misaligned due to restrictions on the position and size of the current terminal with respect to the housing, the through-type By sliding the through-type current transformer that protrudes from the base by aligning the through-hole with the terminal hole of the base, the inner periphery of the through-type current transformer fits into the notch of the current terminal. As a result, the assembly of the feedthrough current transformer and the current terminal with respect to the base can be easily automated.

  The base of the electronic instrument of the present invention regulates the outer periphery of the through-type current transformer in a state where the through-hole of the through-type current transformer and the terminal hole of the base are displaced due to the slide of the through-type current transformer. Therefore, a structure having a step portion for positioning and fixing the through-type current transformer is desirable.

  By adopting such a structure, the stepped portion enables positioning of the through-type current transformer with respect to the base, making it even easier to automate the assembly of the through-type current transformer and the current terminal with respect to the base. .

  The current terminal of the present invention has a U-shape formed by integrally forming a blade-shaped contact located on both sides and a connecting portion connecting the blade-shaped contact, and is inserted into a through-hole of the through-type current transformer. A structure in which a notch is formed in the blade-shaped contact is desirable.

  If such a structure is adopted, even if the through hole of the through-type current transformer and the terminal hole of the base are displaced, the blade-shaped contactor inserted into the through-hole of the through-type current transformer By forming the notches, it is not necessary to configure the blade-shaped contacts located on both sides separately and connect the blade-shaped contacts with screws. As a result, the number of parts can be reduced and the assemblability can be improved.

  The electronic instrument manufacturing method according to the present invention includes a through-type current transformer disposed on the front side of a base that forms a casing with a cover, and a through-hole of the through-type current transformer and a terminal hole of the base, This is an assembling method in which a current terminal is inserted into the through hole and the terminal hole in a state where the position is displaced and led out to the back side of the base.

  As a technical means for achieving the above-mentioned object, the method of manufacturing an electronic instrument according to the present invention is based on the alignment of the through hole of the through type current transformer and the terminal hole of the base. The current terminal is inserted into the through-hole of the through-type current transformer and the terminal hole of the base while protruding from the base, and then the through-type current transformer is slid to be housed on the front side of the base and for current. The through-type current transformer and the current terminal are assembled to the base by fitting the inner periphery of the through-type current transformer into the notch formed in the terminal.

  In the method of manufacturing an electronic instrument according to the present invention, even if the through hole of the through-type current transformer and the terminal hole of the base are misaligned due to restrictions on the position and size of the current terminal with respect to the housing, With the through current transformer protruding from the base due to the alignment of the through hole of the through current transformer and the terminal hole of the base, the current terminal is connected to the through hole of the through current transformer and the terminal hole of the base. Then, the through-type current transformer is slid to be accommodated on the front surface side of the base, and the inner periphery of the through-type current transformer is fitted into the notch formed in the current terminal, so that the The assembly of the feedthrough current transformer and the current terminal can be easily automated.

  In the method of manufacturing an electronic instrument according to the present invention, after the through-type current transformer is slid, the through-hole of the through-type current transformer and the terminal hole of the base are displaced due to the stepped portion formed in the base. It is desirable to position and fix the through-type current transformer by regulating the outer periphery of the through-type current transformer.

  If such a method is adopted, the through-type current transformer can be positioned with respect to the base by the step portion, so that it is even easier to automate the assembly of the through-type current transformer and the current terminal with respect to the base. .

  According to the present invention, even if the through-hole of the through-type current transformer and the terminal hole of the base are misaligned due to restrictions on the position and size of the current terminal with respect to the casing, The through current transformer is slid from the alignment state of the through hole and the terminal hole of the base, and the inner periphery of the through current transformer is inserted into the notch of the current terminal by sliding the through current transformer. By fitting, the assembly of the through-type current transformer and the current terminal to the base can be easily automated. As a result, the assembling property of the feedthrough current transformer and the current terminal with respect to the base can be improved.

It is a perspective view which shows a watt-hour meter unit in embodiment of this invention. It is a perspective view which shows the state which removed the cover by the watt-hour meter unit of FIG. It is the perspective view which looked at the watt-hour meter unit of FIG. 1 from the other side. It is the perspective view which looked at the watt-hour meter unit of FIG. 2 from the opposite side. It is a perspective view which shows the penetration type current transformer which is a component of the watt-hour meter unit. It is a perspective view which shows the terminal for electric current which is a component of the watt-hour meter unit. It is a perspective view which shows the base which is a component of the watt-hour meter unit. It is a top view which shows the state which has arrange | positioned the penetration type current transformer in the base of a watt-hour meter unit. It is a perspective view which shows the state which attaches a penetration type current transformer to a base in the assembly procedure of a watt-hour meter unit. (A) is a perspective view of a partial cross section showing a state in which a through-type current transformer is temporarily placed on a base, and (B) is a plan view of (A). It is a perspective view which shows the state which assembles | attaches the terminal for electric current to a base in the assembly point of an watt-hour meter unit. (A) is a perspective view of a partial cross section showing a state after the current terminal is assembled to the base, and (B) is a plan view of (A). It is a perspective view which shows the state which has arrange | positioned and arrange | positioned the penetration type current transformer with respect to the base in the assembly point of a watt-hour meter unit. (A) is the perspective view of the partial cross section which shows the state after sliding a penetration type current transformer with respect to a base, (B) is a top view of (A).

  Embodiments of an electronic instrument and a manufacturing method thereof according to the present invention will be described below in detail with reference to the drawings. In the following embodiment, the case where it applies to the electronic watt-hour meter as a low voltage | pressure watt-hour meter which measures and displays the electric energy which electric power consumers, such as a general household, measure is displayed.

  This type of electronic watt-hour meter is a terminal block having a power supply side terminal and a load side terminal to which a distribution line is connected while a communication terminal unit, a watt-hour meter unit and a switch unit are assembled on the upper part of the meter body Has a structure attached to the lower part of the instrument body.

  A watt-hour meter unit, which is an electronic meter incorporated in the electronic watt-hour meter, has a built-in measuring circuit that measures the amount of power supplied from a power source to a load via a distribution line.

  The measurement circuit includes a voltage detection unit that detects a voltage applied to the power supply side terminal, a current detection unit that detects a current flowing between the power supply side terminal and the load side terminal, and a voltage and current detection detected by the voltage detection unit. And a power calculation unit that measures the amount of power from the current detected by the unit.

  The current detection unit includes, for example, a cylindrical through-type current transformer (CT) having a structure in which a core on which a coil is mounted is stored in an exterior case.

  In the following embodiment, a case where the present invention is applied to a single-phase or three-phase three-wire watt-hour meter unit incorporated in an electronic watt-hour meter will be described, but the present invention is not limited to this, and a current is detected. The present invention can also be applied to other electronic instruments having a current detection unit equipped with a through-type current transformer.

  As shown in FIGS. 1 to 4, the watt-hour unit of this embodiment has a display window 12 for displaying the amount of power on the front side of the housing 11, and a voltage terminal 13 on the back side of the housing 11. And a structure in which the current terminals 14 and 15 are derived. The housing 11 includes a resin-made rectangular plate base 16 and a resin-made rectangular box-shaped cover 17 attached to the front side of the base 16.

  The base 16 is assembled with three voltage terminals 13, two types of current terminals 14 and 15, and through-type current transformers 18 and 19 which are components of the watt-hour meter unit. A part of the voltage terminal 13, a part of the current terminals 14 and 15, and the through-type current transformers 18 and 19 are accommodated in the housing 11 by attaching the cover 17 to the base 16.

  Hereinafter, among the components of the watt-hour meter unit, the through current transformers 18 and 19, the current terminals 14 and 15, and the base 16 will be described in detail.

  As shown in FIG. 5, the through-type current transformers 18 and 19 have a cylindrical shape in which a core on which a coil is mounted is stored in an outer case 20, and the through-type current transformer includes two sets of coils and a core. 18 and 19 are integrated by an outer case 20. Thus, by integrating the two sets of through-type current transformers 18 and 19 with the exterior case 20, the through-type current transformers 18 and 19 can be easily assembled to the base 16.

  As shown in FIG. 6, there are two types of current terminals 14 and 15, a wide U-shaped current terminal 14 and a narrow U-shaped current terminal 15. One current terminal 14 is a conductive member in which blade-shaped contacts 21 and 22 located on both sides and a connecting portion 23 that connects the blade-shaped contacts 21 and 22 are integrally formed. The other current terminal 15 is a conductive member formed integrally with blade-shaped contacts 24 and 25 located on both sides and a connecting portion 26 that connects the blade-shaped contacts 24 and 25.

  In one current terminal 14, a notch 28 is formed in a blade-shaped contact 21 (on the right side in the drawing) inserted through the through hole 27 of the through-type current transformer 18. When the current terminal 14 is assembled to the base 16, the through-type current transformer 18 can be assembled by fitting the inner peripheral portion 29 (see FIG. 5) of the through-type current transformer 18 into the notch 28. ing.

  In the other current terminal 15, a notch 31 is formed in the blade-shaped contact 25 (left side in the drawing) inserted through the through hole 30 of the through-type current transformer 19. When the current terminal 15 is assembled to the base 16, the through-type current transformer 19 can be assembled by fitting the inner peripheral portion 32 (see FIG. 5) of the through-type current transformer 19 into the notch 31. ing.

  Thus, in order to enable assembly of the through-type current transformers 18 and 19, the current terminals 14 and 15 include the blade-shaped contacts 21, 22, 24 and 25 located on both sides and the blade-shaped contacts 21. , 22, 24, 25 are integrally formed with connecting portions 23, 26 to form a U-shape, and one blade-shaped contactor inserted into the through holes 27, 30 of the through-type current transformers 18, 19. Cutouts 28 and 31 are formed in 21 and 25.

  As a result, the current terminals 14 and 15 do not need to have a structure in which the blade-shaped contacts located on both sides are formed separately and the blade-shaped contacts are connected by screws. By using the current terminals 14 and 15 in which the blade contacts 21, 22, 24, and 25 located on both sides are integrated as in this embodiment, the number of parts can be reduced because there are no two members. Since screwing is not necessary, the assemblability can be improved.

  As shown in FIG. 7, the base 16 has four terminal holes 33 to 36 through which the blade contacts 21 and 22 of the current terminal 14 and the blade contacts 24 and 25 of the current terminal 15 are inserted. It is arranged. The through-type current transformers 18 and 19 are provided in a region including a terminal hole 33 through which the blade contact 21 of the current terminal 14 is inserted and a terminal hole 35 through which the blade contact 25 of the current terminal 15 is inserted. A partition wall 37 is provided in accordance with the substantially whole shape of At both ends of the partition wall 37, stepped portions 38 are provided for temporarily placing the through-type current transformers 18 and 19 during the assembly of the through-type current transformers 18 and 19.

  Hereinafter, the assembled state of the through-type current transformers 18 and 19 and the current terminals 14 and 15 to the base 16 will be described in detail with reference to FIGS. 2 and 4.

  As shown in FIGS. 2 and 4, the through-type current transformers 18 and 19 are positioned and arranged in a region surrounded by the partition wall 37 (see FIG. 7) of the base 16.

  The blade-shaped contact 21 of the current terminal 14 is inserted into the through hole 27 of the through-type current transformer 18 and the terminal hole 33 (see FIG. 7) of the base 16 and led out to the back side of the base 16. At this time, the inner peripheral portion 29 (see FIG. 5) of the through-type current transformer 18 is fitted into the notch 28 (see FIG. 6) of the blade-shaped contact 21. The blade contact 22 of the current terminal 14 is inserted into the terminal hole 36 (see FIG. 7) of the base 16 and led out to the back side of the base 16.

  The blade contact 24 of the current terminal 15 is inserted into the terminal hole 34 (see FIG. 7) of the base 16 and led out to the back side of the base 16. The blade-shaped contact 25 of the current terminal 15 is inserted into the through hole 30 of the through-type current transformer 19 and the terminal hole 35 (see FIG. 7) of the base 16 and led out to the back side of the base 16. At this time, the inner peripheral portion 32 (see FIG. 5) of the through-type current transformer 19 is fitted into the notch 31 (see FIG. 6) of the blade-shaped contact 25.

  In this manner, by inserting the blade-shaped contacts 21 and 25 of the current terminals 14 and 15 into the through holes 27 and 30 of the two through-type current transformers 18 and 19, the current terminals 14 and 15 are connected to each other. A two-circuit current detection unit is configured to detect the current flowing through the blade-shaped contacts 21 and 25 with the through-type current transformers 18 and 19.

  By the way, the blade-shaped contacts 21 and 22 of the current terminal 14 and the blade-shaped contacts 24 and 25 of the current terminal 15 led out to the back side of the base 16 are provided in the instrument body of the electronic watt-hour meter. Inserted into the blade contact. On the other hand, in the electronic watt-hour meter, the position and size of the blade receiving contact of the meter body to which the watt-hour unit is assembled are defined.

  Since there is such a regulation, in the watt hour unit, the positions and dimensions of the blade-shaped contacts 21 and 22 of the current terminal 14 and the blade-shaped contacts 24 and 25 of the current terminal 15 with respect to the housing 11 (blade) Width).

  If there is such a restriction, as shown in FIG. 8, the through holes 27 and 30 of the through-type current transformers 18 and 19 accommodated in the housing 11 and the blade-shaped contacts 21 of the current terminals 14 and 15. , 25 may be displaced relative to the terminal holes 33, 35 of the base 16 through which the holes are inserted.

  That is, in the state where the through-type current transformers 18 and 19 are positioned and arranged in the region surrounded by the partition wall 37 of the base 16, the through-holes 27 and 30 of the through-type current transformers 18 and 19 to the terminal holes 33 of the base 16. , 35 (a broken line portion in the figure) protrudes.

  In such a state, the blade-shaped contacts 21 and 25 of the current terminals 14 and 15 can be directly inserted into the through holes 27 and 30 of the through-type current transformers 18 and 19 and the terminal holes 33 and 35 of the base 16. Can not.

  Therefore, in this embodiment, the through-type current transformers 18 and 19 and the current terminals 14 and 15 are assembled to the base 16 in the following manner. The procedure for assembling the through-type current transformers 18 and 19 and the current terminals 14 and 15 to the base 16 will be described in detail below with reference to FIGS.

  First, as shown in FIG. 9, the through-type current transformers 18 and 19 are placed on the base 16. At this time, the through-type current transformers 18 and 19 are temporarily placed in a stepped portion 38 in a region surrounded by the partition wall 37 of the base 16.

  As a result, as shown in FIGS. 10A and 10B, a part of the through-type current transformers 18 and 19 protrudes from the base 16, but the through-holes 27 and 30 of the through-type current transformers 18 and 19. And the terminal holes 33 and 35 of the base 16 are aligned with each other without being displaced. In this state, the blade-shaped contacts 21 and 25 of the current terminals 14 and 15 can be directly inserted into the through holes 27 and 30 of the through-type current transformers 18 and 19 and the terminal holes 33 and 35 of the base 16.

  After temporarily placing the through-type current transformers 18 and 19 on the base 16, as shown in FIG. 11, the blade-shaped contacts 21 and 25 of the current terminals 14 and 15 are passed through the through-type current transformers 18 and 19. The holes 27 and 30 and the terminal holes 33 and 35 of the base 16 are inserted. The blade contacts 22 and 24 of the current terminals 14 and 15 are inserted into the terminal holes 36 and 34 of the base 16.

  At this time, as shown in FIGS. 12A and 12B, a part of the through-type current transformers 18 and 19 protrudes from the base 16, but the through-holes 27 and 30 of the through-type current transformers 18 and 19. And the terminal holes 33 and 35 of the base 16 are aligned with each other without being displaced, so that the blade-shaped contacts 21 and 25 of the current terminals 14 and 15 are connected to the through-type current transformers 18 and 19. It is smoothly inserted into the through holes 27 and 30 and the terminal holes 33 and 35 of the base 16.

  After the insertion of the current terminals 14 and 15, as shown by the white arrows in FIGS. 12A and 12B, the through-type current transformers 18 and 19 are moved to the opposite side to the protruding direction with respect to the base 16. Push in. As a result, as shown in FIG. 13, the through-type current transformers 18 and 19 are positioned and arranged by dropping from the stepped portion 38 of the base 16 into a normal region surrounded by the partition wall 37.

  At this time, as shown in FIGS. 14A and 14B, the inner peripheral portions 29 of the through-type current transformers 18 and 19 are formed in the notches 28 and 31 of the blade-shaped contacts 21 and 25 of the current terminals 14 and 15. , 32 can be positioned and positioned in the normal region surrounded by the partition wall 37 of the base 16.

  As described above, through the restriction of the position and dimensions (blade width) of the blade-shaped contacts 21 and 25 of the current terminals 14 and 15 with respect to the base 16, the through-holes 27 and 30 and the terminal holes 33 and 35 of the base 16 are relatively displaced, the assembling property of the through-type current transformers 18 and 19 and the current terminals 14 and 15 with respect to the base 16 is as follows. Can be improved.

  That is, sliding the through-type current transformers 18 and 19 from the alignment state of the through-holes 27 and 30 of the through-type current transformers 18 and 19 and the terminal holes 33 and 35 of the base 16, and the through-type current transformers By inserting the inner peripheral portions 29 and 32 of the through-type current transformers 18 and 19 into the notches 28 and 31 of the current terminals 14 and 15 by the slides 18 and 19, the through-type current transformer 18 and the base 16 are inserted. 19 and current terminals 14 and 15 can be easily assembled and the number of parts can be reduced, so that the assembly can be easily automated.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

14, 15 Current terminal 16 Base 17 Cover 18, 19 Through-type current transformer 27, 30 Through hole 28, 31 Notch 29, 32 Inner peripheral portion 33, 35 Terminal hole 38 Step portion

Claims (5)

A base that forms a housing with a cover, a through-type current transformer disposed on the front side of the base, and a through-hole in a state where the through-hole of the through-type current transformer and the terminal hole of the base are displaced And an electronic instrument provided with a current terminal inserted into the terminal hole and led to the back side of the base,
The current terminal is formed by sliding the through-type current transformer that protrudes from the base by aligning the through-hole of the through-type current transformer and the terminal hole of the base. An electronic instrument characterized by having a notch into which is fitted.   The base has a through-type current transformer by regulating the outer periphery of the through-type current transformer in a state where the through-hole of the through-type current transformer and the terminal hole of the base are displaced by the slide of the through-type current transformer. The electronic instrument according to claim 1, further comprising a step portion for positioning and fixing the instrument.   The current terminal has a U-shape formed integrally with a blade contact located on both sides and a connecting portion connecting the blade contact, and is inserted into a through hole of the through-type current transformer. The electronic instrument according to claim 1 or 2, wherein a notch is formed in the blade-shaped contact. A through-type current transformer is arranged on the front side of the base that forms the housing with the cover, and the through-hole and the terminal hole have a current misaligned with the through-hole of the through-type current transformer and the terminal hole of the base being displaced. A method of manufacturing an electronic instrument that allows a terminal for insertion to be led out to the back side of the base,
With the through-type current transformer protruding from the base by the alignment of the through-hole of the through-type current transformer and the terminal hole of the base, the current terminal is connected to the through-hole of the through-type current transformer and the base terminal. After passing through the hole, the through-type current transformer is slid and accommodated on the front side of the base, and the inner periphery of the through-type current transformer is fitted into the notch formed in the current terminal. A method of manufacturing an electronic instrument, comprising assembling a through-type current transformer and a current terminal.   After sliding the through-type current transformer, the outer periphery of the through-type current transformer is regulated with the stepped part formed in the base in a state where the through-hole of the through-type current transformer and the terminal hole of the base are displaced. 5. The method of manufacturing an electronic instrument according to claim 4, wherein the through-type current transformer is positioned and fixed by doing so.

Images