JP3200501B2 - Noise-prevention type multi-strip conversion connector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise-preventing multi-wire conversion connector for a multi-wire transmission line having a built-in inductor for blocking a common mode noise current transmitted through a signal transmission line composed of a large number of core wires over a wide band. About.

[0002]

2. Description of the Related Art Conventionally, when communication is performed between various transmission devices and terminal devices via a multi-wire signal transmission line, a multi-wire conversion connector for connecting the device and the transmission line is used. A coil wound around a toroidal core (hereinafter referred to as a toroidal coil) is incorporated in the connector to reduce common mode noise transmitted through the multi-wire transmission line.

FIG. 2 shows a conventional RS-
1 is a perspective view of an example of a multi-wire conversion connector including a multi-core connector for connecting a 232C interface cable and a jack of a modular connector for home wiring.

In FIG. 2, 1 is a multi-terminal connector of an RS232C interface, 2 is a modular plug, 3 is a modular jack fitted with the modular plug 2, 4 is a conversion connector housing, and 5 is a conversion connector housing 4. It is a built-in toroidal coil.

Although the number of cores of the cable connected to the modular connector is eight at the maximum, the number of cores of the multi-core connector 1 is various such as 9, 15, 25 in the case of RS-232C. Since the number of cores is larger than that of the connector, only the same number of terminals as the number of cores of the modular connector are used.

A toroidal coil 5 is used to reduce the common mode noise current transmitted through the multi-wire transmission line from either side of these conversion connectors.

FIG. 3 is a partially cutaway cross-sectional view of the toroidal coil, wherein 6 is a toroidal core, 7 is a multi-wire winding transmission line wound around the core 6,.
,..., N ′ are input / output terminals of the transmission line 7 composed of n cores.

In order to block a common mode noise current over a wide band, it is necessary to use a toroidal coil having a large inductance. Since the inductance of the toroidal coil 5 is proportional to the magnetic permeability of the core, the cross-sectional area, and the number of turns of the coil, it is necessary to increase the number of turns in order to obtain a large inductance with a small core having a small cross-sectional area when the magnetic permeability is the same.

Increasing the number of turns increases the stray capacitance of the winding, and in the case of a toroidal core, the effective stray capacitance between the beginning and end of winding of the winding increases.

[0010]

However, when a large number of coils are wound around a small toroidal core as described above, the coils are densely packed inside the core, and as shown in FIG. Since stray capacitance Cs is generated, when common mode noise current conducted through a multi-wire transmission line or high frequency is
Since the coil is bypassed through s, there is a problem that the noise attenuation characteristic is deteriorated in a high frequency range.

[0011] In order to solve the above problems, an object of the present invention is to reduce stray capacitance between input and output terminals of the coil and improve attenuation characteristics in a high frequency range.

[0012]

In order to solve the above-mentioned problems, the present invention uses a rectangular core composed of three long magnetic paths instead of a conventionally used toroidal core, A plurality of pair wires related to signal transmission of the multi-wire transmission line are collectively divided and wound at a predetermined position of the center magnetic path, and densely in a short portion of the center magnetic path, the remaining long of the center magnetic path is long. The portion is sparsely wound with a different number of windings to reduce the effective stray capacitance between the input and output of the winding and increase the attenuation of high-frequency common mode noise.

[0013]

The generation of magnetic flux for the common mode noise current and the normal mode signal current when the pair wire is divided and wound around the rectangular core as described above, as shown in FIGS. 4 (a) and 4 (b), respectively. Become.

In FIG. 4A, the induced magnetic fluxes φci and φcj in the core 9 due to the common mode current Ic flowing through the arbitrary paired wires ii ′ and jj ′ of the multi-filar winding transmission line are the same. Since they occur in the directions, they mutually strengthen each other and have a large inductance.

Next, in FIG. 4 (b), induced magnetic fluxes .phi.ni and .phi.nj in the core due to the normal mode current In flowing through arbitrary pair lines i-i 'and j-j' are reversed in the loop in the core and cancel each other. .

Therefore, if the paired wires are wound together, the leakage inductance for the paired wires is reduced, and the transmission loss can be reduced even when the normal mode signal current is at a high frequency.

If all the paired wires including these paired wires are twisted and then wound, the windings of each paired wire with respect to the core are not unbalanced, so that the transmission signal of one paired wire becomes different from the other. Crosstalk leaking to the pair wire is reduced.

Therefore, by selecting the magnetic permeability of the core 9 and the winding method, it is possible to reduce the stray capacitance, broaden the attenuation characteristic with respect to the common mode noise current, and reduce the transmission loss and crosstalk with respect to the normal mode signal current. it can.

FIG. 10 is a comparison diagram of the frequency characteristics of the amount of attenuation with respect to common mode noise between the conventional noise prevention type multi-wire conversion connector and the first embodiment of the present invention. The frequency at which the amount of 25 dB can be obtained is about 3 MHz (point A) in the related art, but can be increased to ten and several MHz (point B) according to the present invention.

[0020]

FIG. 1 is an explanatory view of a first embodiment of the present invention. FIG. 1 (a) is a perspective view showing its structure, FIG. 1 (b) is a connection diagram, and FIG. 1 (c) is an equivalent circuit. It is.

In FIG. 1A, 1 is a multi-core connector,
3 is a modular connector jack, 4 is a conversion connector housing, 8 is a winding portion for inserting a coil wound on a winding frame (not shown), 9 is a high frequency rectangular closed magnetic circuit core (usually E-shaped). After inserting the coil into the shaped core, the I-shaped core is brought into close contact to form a square shape.) 10 is a coil that is densely wound with a pair of wires aligned with a short length l ₁ portion of the center magnetic path via a winding frame. , 1
Coil 1 was turned sparsely wound pair line through the winding frame to the longer length l ₂ parts of the central magnetic path, 12 is a printed board mounted with the core 9 and the modular jack 3.

In FIG. 1C, C ₁ and C ₂ are stray capacitances generated between the windings of the coils 10 and 11,
₁ has a large stray capacitance because the winding is intensively wound around the magnetic path length l ₁ , whereas C ₂ is sparsely formed on the magnetic path length l _2. Because it is wound, the stray capacitance is small.

Therefore, the total stray capacitance C _s of the winding is C ₁ and C
₂ is a value connected in series, which is smaller than C ₂ ,
Since the floating capacitance of the conventional toroidal coil 5 is much smaller than that of the conventional toroidal coil 5, the blocking performance against high-frequency common mode noise is greatly improved.

FIG. 5 is an explanatory diagram of a second embodiment of the present invention.
FIG. 5A is a perspective view showing the structure, and FIG. 5B is a cross-sectional view taken along the line AA after assembling the components shown in FIG. 5A.

In the second embodiment shown in FIG.
The same members as those in the first embodiment shown in FIG.

In FIGS. 5 (a) and 5 (b), 12 'is the first
A magnetic plate material (a magnetic plate material having the same high-frequency characteristics as the square core 9 and used in place of the printed board 12 of
Reference numeral 13 denotes a winding through hole formed in the plate member 12 'and has the same size as the two loop inner diameters of the core 9.

Reference numeral 14 denotes a winding portion for inserting a coil wound on a winding frame (not shown). Reference numeral 15 denotes a predetermined position of the back contact piece of the multi-core connector 1 which is connected to a lead wire of the coil 10. Is a through hole for a terminal of the modular jack 3 provided on the magnetic member 12 ', and 17 is a contact spring in the modular jack 3.

As shown in FIG. 5B, the magnetic plate 12 '
The core 9 is superimposed on the position of the winding through opening 13 of
The coil is inserted by aligning the center magnetic path of (1) with the winding portion 14 of the magnetic plate 12 '.

FIG. 6 shows the core 9 of the second embodiment shown in FIG.
FIG. 6 (a) is a perspective view, and FIG. 6 (a) is an explanatory view of a third embodiment of the present invention in which an auxiliary core 9 ″ is provided in contact with a bent portion of a bent core 9 ′ obtained by bending the wire into an L shape. b) is A in FIG.
FIG. 6C is a perspective view of the auxiliary core 9 ″.

The center core magnetic path length l ₁ of the auxiliary core 9 ″ is equal to the center magnetic path length of the bent portion of the bent core 9 ′.
Concentrated winding is applied to this portion with both cores together to form the coil 10. Further, the remaining portion l ₂ of the bent core is made longer than l ₁ , and a sparse winding is applied to this portion to make the coil 11
To form

With such a configuration, the stray capacitances C ₁ and C ₂ of the coil 10 and the coil 11 act in series with respect to the high-frequency common mode noise current, so that the stray capacitance C ₂ of the coil 11 is small. Also, the noise attenuation does not decrease even in a high frequency range.

Further inductance of the coil 10 centered winding _part l increases by the effect of the auxiliary core 9 ', the low-frequency characteristics are also improved broadband characteristics can be obtained.

FIG. 7 is an explanatory view of a fourth embodiment of the present invention.
A varistor for lightning surge protection is mounted on the back surface of the printed circuit board 12 of the first embodiment shown in FIG. 1, and has a function of blocking both common mode noise and surge conducted on the transmission line. 7A is a perspective view showing the structure, FIG. 7B is a sectional view taken along the line AA in assembling of FIG. 7A,
FIG. 7C is a connection diagram.

In FIG. 7, reference numeral 18 denotes a chip type varistor.
A multi-terminal varistor in which one electrode of the chip-type varistor 18 is shared is also applicable.

As shown in FIG. 7, the core 9 of the printed board 12 is
A varistor 18 is cut out in the vicinity of the mounting position, and a common terminal of the varistor 18 is connected to a frame ground (hereinafter, referred to as FG) of the multi-terminal connector 1. Accordingly, the varistor 18 operates regardless of the surge current inflow from either side, and the varistor 18 can be bypassed to the ground via the FG.

FIG. 8 shows a varistor 1 according to the fourth embodiment of FIG.
In the connection diagram of the fifth embodiment of the present invention in which a capacitor 19 is connected in place of 8, when used in a system that can be grounded, the FG is connected to ground to further increase the common mode noise current blocking effect. can do.

FIG. 9 shows a multi-core connector 1 that uses a cable holding clamp instead of the modular jack 3 of the first embodiment shown in FIG. 1 and directly controls the number of cable cores via a coil portion (not shown). FIG. 14 is a perspective view of a sixth embodiment of the present invention provided with a cable fixing portion when connecting to a cable.

In FIG. 9, reference numeral 20 denotes a multi-wire cable, 2
1 is a cable holding clamp, and is a modular jack 3
In the case where the clamp 21 is used instead of the above, and the cable is used connected to a multi-terminal connector via a coil portion without limiting the number of cores of the multi-wire cable, common mode noise transmitted through the cable is prevented. can do.

In the above description, the case where the concentrated winding and the loose winding are applied as the winding method of the square core around the center magnetic path has been described. It is needless to say that the pair wire may be wound evenly.

[0040]

As described in detail above, the present invention provides
Instead of the conventional toroidal core, a square core that can reduce the stray capacitance between the input and output windings is used, and a plurality of pair wires related to signal transmission of the multi-wire transmission line are collectively arranged at the center magnetic path portion of the core. By forming a coil wound uniformly evenly or partially concentrated and a coil wound sparsely, the stray capacitance is reduced, and the blocking characteristic against high-frequency common mode noise current is reduced to a high range. In addition, the blocking characteristic is improved by increasing the inductance in the low frequency range by the concentrated winding, as shown in FIG.
As shown in FIG.

Further, by winding the plural pairs of wires in parallel, there is also an effect that the leakage inductance between the wires can be reduced and the transmission loss for a high-frequency transmission signal can be reduced. Furthermore, when a plurality of paired wires are twisted and wound around a core, an effect that a transmission signal of one paired wire can be reduced in crosstalk between other paired wires can be expected.

[Brief description of the drawings]

FIGS. 1A and 1B are explanatory views of a first embodiment of the present invention, wherein FIG. 1A is a perspective view showing the structure, FIG.
(C) is an equivalent circuit diagram.

FIG. 2 is a perspective view of an example of a conventional multi-wire conversion connector.

FIG. 3 is a partially cutaway sectional view of the toroidal coil.

FIG. 4 is an explanatory diagram of a magnetic flux generated by a common mode noise current and a normal mode signal current when a pair wire is dividedly wound around a square core.

FIG. 5 is an explanatory view of a second embodiment of the present invention, wherein FIG.
FIG. 5B is a perspective view showing the structure, and FIG.
It is -A sectional drawing.

FIG. 6 is an explanatory view of a third embodiment of the present invention, wherein FIG.
6A is a perspective view showing the structure, and FIG.
FIG. 6C is a sectional view of the auxiliary core 9 ″.

FIG. 7 is an explanatory view of a fourth embodiment of the present invention, wherein FIG.
FIG. 7B is a perspective view showing the structure, and FIG.
7A is a connection diagram. FIG.

FIG. 8 is a connection diagram of a fifth embodiment of the present invention.

FIG. 9 is a perspective view of a sixth embodiment of the present invention in which a cable fixing portion is provided instead of the modular jack of the embodiment shown in FIG.

FIG. 10 is a comparison diagram of common mode noise attenuation between a conventional product of the noise-prevention type multi-strip conversion connector and a product of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Multi-core connector 2 Modular plug 3 Modular jack 4 Conversion connector housing 5 Toroidal coil 6 Toroidal core 7 Multi-wire winding transmission line 8 Winding part 9 Square closed magnetic circuit core 9 'Bending core 9' Auxiliary core 10 Dense Wound coil 11 Sparsely wound coil 12 Printed board 12 'Magnetic plate material 13 Winding opening 14 Coil insertion part 15 Pin 16 Terminal through hole 17 Contact spring 18 Chip varistor

────────────────────────────────────────────────── ─── Continuation of the front page (72) Kunio Hattori, Inventor Nippon Telegraph and Telephone Corporation, 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo (56) References JP-A-63-38220 (JP, A) 2-132806 (JP, A) JP-A-4-14308 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 17/04, 17/06, 27/00 H01F 27 / 28,27 / 29,37 / 00 H01R 13/719

Claims (1)

(57) [Claims] 1. A connector mounted on an information transmission device and fitted to a multi-core connector in which a plurality of input / output signal lines of the device are connected to predetermined terminals, and a multi-wire strip for transmitting input / output signals of the device. A noise-prevention-type multi-wire conversion device comprising noise prevention means for reducing common-mode noise transmitted to the multi-wire transmission line between the modular connector jack and a modular connector plug connected to the transmission line. In the connector, a high-frequency rectangular shape including a conversion connector housing, a modular connector jack mounted on a predetermined portion of the conversion connector housing, a multi-core connector, and three long-side magnetic paths built in the conversion connector housing. towards from one side of the central long side magnetic path of a closed magnetic path core the high frequency rectangular shape closed magnetic path core on the other side
Is configured with the high frequency rectangular shape closed magnetic path core formed by turning sparsely around the tightly wound Rotate The predetermined long parts in a predetermined short portion by aligning multiple wire pairs in one direction A noise-prevention type multi-strip conversion connector characterized by the following.