CN102769439A

CN102769439A - Filter circuit applied to connector

Info

Publication number: CN102769439A
Application number: CN2011101131961A
Authority: CN
Inventors: 徐勇春
Original assignee: Foxconn Kunshan Computer Connector Co Ltd; Hon Hai Precision Industry Co Ltd
Current assignee: Foxconn Kunshan Computer Connector Co Ltd; Hon Hai Precision Industry Co Ltd
Priority date: 2011-05-03
Filing date: 2011-05-03
Publication date: 2012-11-07

Abstract

The invention discloses a filter circuit applied to a connector, which comprises a cable side, a physical side, a transformer connected between the two sides, a common mode choke, a ground point and a surge suppressing element. The transformer comprises a first coil and a second coil, wherein the first coil is provided with a centre tap and two first connection ends connected at the cable side, and the second coil is provided with two second connection ends. The common mode choke comprises a third coil and a fourth coil, wherein the third coil is connected between one second connection end and the physical side, and the fourth coil is connected between the other second connection end and the physical side. The surge suppressing element is connected between the centre tap and the ground point and controls the connection and disconnection of the centre tap and the ground point. The design of the filter circuit effectively inhibits the ground point inputting a noise current to the circuit and improves the performance of the circuit.

Description

Be applied to the filter circuit of connector

[technical field]

The present invention relates to a kind of filter circuit that is applied to connector, particularly relate to a kind of filter circuit with interconnective transformer and common mode choke.

[background technology]

On January 11st, 2011, the notification number of bulletin was the TaiWan, China patent of M396531; Its 8th figure has disclosed a kind of filter circuit; Its cable-side that is provided with input and output each other and physical side, be connected in transformer between these both sides with common mode choke, earth point, have the surge suppression element of certain conducting voltage and a conductive branch (it comprise resistance and the electric capacity of connecting) parallelly connected with the surge suppression element; Transformer comprises first coil and second coil of primary coil and secondary coil each other; First coil is provided with centre cap and is connected in two first links of cable-side; Second coil is provided with two second links that connect common mode choke; Common mode choke comprises tertiary coil and the 4th coil, and tertiary coil is connected between one second link and the physical side, and the 4th coil is connected between another second link and the physical side; The surge suppression element is connected between the centre cap and earth point of first coil with said conductive branch mutually side by side, and the surge suppression element plays the effect that the overvoltage of surge or thunderbolt generation is imported earth point.

In practical application, earth point not only can absorb the noise electric current, because earth point and nisi zero potential point; It can have non-constant fainter simultaneously potential value, thereby also can produce feedback current to the circuit that is connected, promptly; Earth point can produce noise and disturb to the circuit that is connected, in the background technology, because the existence of the conductive branch parallelly connected with the surge suppression element; The conducting no matter whether the surge suppression element is excited; Earth point all can be in connected state with centre cap through conductive branch, thereby earth point is exported the noise electric current through conductive branch to centre cap, influences the performance of circuit.

[summary of the invention]

The object of the present invention is to provide a kind of filter circuit that is applied to connector, thereby it improves to circuit input noise electric current performance through centre cap through suppressing earth point.

For realizing above-mentioned purpose; Filter circuit of the present invention adopts following technical scheme: a kind of filter circuit that is applied to connector; It has the cable-side and the physical side of input and output each other, the surge suppression element that is connected in transformer and common mode choke, the earth point between these both sides and has certain conducting voltage; Transformer comprises first coil and second coil that intercouples; First coil is provided with centre cap and is connected in two first links of cable-side; Second coil is provided with two second links that connect common mode choke, and common mode choke comprises tertiary coil and the 4th coil, and tertiary coil is connected between one second link and the physical side; The 4th coil is connected between another second link and the physical side; The surge suppression element comprises corresponding first end and corresponding second end that is communicated with earth point that is communicated with the centre cap of first coil, thereby when the voltage between the said two ends of surge suppression element reached conducting voltage surge suppression element and is excited conducting, the centre cap of first coil passed through the surge suppression element and is conducted with earth point; When thereby the voltage between the said two ends of surge suppression element did not reach conducting voltage surge suppression element and is not excited conducting, the centre cap of said first coil broke off with earth point mutually.

For the present invention; When thereby the voltage between the said two ends of surge suppression element reached conducting voltage surge suppression element and is excited conducting, the centre cap of first coil was conducted with earth point through the surge suppression element, thereby when the voltage between the said two ends of surge suppression element does not reach conducting voltage surge suppression element and is not excited conducting; The centre cap of said first coil breaks off with earth point mutually; The surge suppression element is being controlled conducting and the disconnection between centre cap and earth point, and when circuit met with the overvoltage of surge or thunderbolt generation, conducting further was imported into earth point thereby said overvoltage excites the surge suppression element; Surge or thunderbolt are of short duration and the haphazard part after all; Under common state, the surge suppression element can not meet with the overvoltage of surge or thunderbolt generation, but is in not conducting state; Make earth point break off mutually with centre cap; The faint electromotive force that earth point has can't form the noise electric current to centre cap, and the design of this circuit effectively suppresses earth point and through centre cap circuit imported the noise electric current, and circuit performance improves.

Below in conjunction with accompanying drawing and preferred embodiment the present invention is described further.

[description of drawings]

Fig. 1 is the circuit diagram that meets the filter circuit of first embodiment of the invention.

Fig. 2 is the circuit diagram that meets the filter circuit of second embodiment of the invention.

[main element symbol description]

Filter circuit

1,2

Cable-side 100

Physical side 101

Transformer 11

First coil

110,21

Second coil 111

First link 112

Centre cap 113,115,210

Second link 114

Common mode choke 12

Tertiary coil 120

The 4th coil 121

The 5th coil 122

Earth

point

13,24

Surge suppression element 14,23

First end 140

Second end 141

Electric capacity 15

Resistance 22

[embodiment]

See also shown in Figure 1; The filter circuit 1 of first embodiment according to the invention; It is applied to connector (not shown), and said filter circuit 1 has the cable-side 100 and the physical side 101 of input and output each other, the surge suppression element 14 that is connected in transformer 11 and common mode choke 12, the earth point 13 between these both sides and has certain conducting voltage.Transformer 11 comprises first coil 110 and second coil 111 that intercouples.First coil 110 is provided with centre cap 113 and is connected in two first links 112 of cable-side 100.Second coil 111 is provided with two second links 114 and the centre cap 115 that connects common mode choke 12.Common mode choke 12 comprises tertiary coil 120, the 4th coil 121 and the 5th coil 122 that is connected with the centre cap 115 of second coil 111, and common mode choke 12 is a three-wire type, and it also can be twin wire certainly, promptly is not provided with the 5th coil 122.Tertiary coil 120 is connected between one second link 114 and the physical side 101, and the 4th coil 121 is connected between another second link 114 and the physical side 101.Surge suppression element 14 comprises corresponding first end 140 and corresponding second end 141 that is communicated with earth point 13 that is communicated with the centre cap 113 of first coil 110; When thereby the voltage between surge suppression element 14 said two ends reaches conducting voltage surge suppression element 14 and is excited conducting; The centre cap 113 of first coil 110 is conducted through surge suppression element 14 and earth point 13; When thereby the voltage between surge suppression element 14 said two ends did not reach conducting voltage surge suppression element 14 and is not excited conducting, the centre cap 113 of said first coil 110 broke off with earth point 13 mutually.Surge suppression element 14 is being controlled the conducting and the disconnection of 13 of centre cap 113 and earth points.Surge suppression element 14 plays the effect that the overvoltage of surge or thunderbolt generation is imported earth point 13, and in this execution mode, surge suppression element 14 is thyristor or gas discharge tube, but does not exceed with above-mentioned two kinds.The conducting voltage of surge suppression element 14 is 300V; Be that voltage between surge suppression element 14 said two ends reaches (promptly being equal to or greater than) 300V; Surge suppression element 14 conducting that is excited; Voltage between surge suppression element 14 said two ends does not reach (promptly less than) 300V, and conducting is not in off-state thereby surge suppression element 14 is excited.Certainly the conducting voltage of surge suppression element 14 of the present invention is not obviously exceeded with 300V, visual actual needs and to select conducting voltage for use be the surge suppression element 14 of other values.The centre cap 113 of said first coil 110 directly connects surge suppression element 14 backs and further connects earth point 13,, is not connected with other electronic components between the centre cap 113 of said first coil 110 and the surge suppression element 14 that is.The 5th coil 122 has two links (not label); One link of the 5th coil 122 connects the centre cap 115 of second coil 111; Another link of the 5th coil 122 is connected in an electric capacity 15 back ground connection; In this execution mode, another link of the 5th coil 122 is directly connected in electric capacity 15 back ground connection, and another link of certain the 5th coil 122 also can be connected in other electronic components (like resistance) earlier; Further connect electric capacity 15 back ground connection again, promptly another link of the 5th coil 122 can be connected in electric capacity 15 back ground connection indirectly.In connector, said centre cap 113 is communicated to earth point 13 must pass through surge suppression element 14, and promptly in connector, surge suppression element 14 must be passed through in the said conducting wire that centre cap 113 is communicated with earth point 13.

See also shown in Figure 2; The filter circuit 2 of second embodiment according to the invention; Only be connected with surge suppression element 23 and resistance 22 between the centre cap 210 of its earth point 24 and transformer first coil 21; And the centre cap 210 of first coil 21, resistance 22, surge suppression element 23 and earth point 24 connect successively, also can so design for filter circuit 1.

Claims

1. A filter circuit applied to a connector, which has a cable side and a physical side for mutual input and output, a transformer connected between the two sides, a common mode choke coil, a grounding point, and a certain conduction voltage The surge suppression element, the transformer includes a first coil and a second coil coupled to each other, the first coil is provided with a center tap and two first connection ends connected to the cable side, the second coil is provided with a common mode choke coil The common mode choke coil includes a third coil and a fourth coil, the third coil is connected between a second connection end and the physical side, and the fourth coil is connected between the other second connection end and the physical side. Between the sides, the surge suppression element includes a first end corresponding to the center tap of the first coil and a second end corresponding to the ground point, characterized in that: when the voltage between the two ends of the surge suppression element reaches When the conduction voltage is activated and the surge suppression element is turned on, the center tap of the first coil passes through the surge suppression element and conducts with the ground point. When the voltage between the two ends of the surge suppression element does not reach the conduction voltage Therefore, when the surge suppression element is not excited to be turned on, the center tap of the first coil is disconnected from the ground point.

2. The filter circuit according to claim 1, wherein the surge suppression element is a thyristor or a gas discharge tube.

3. The filter circuit according to claim 1, wherein the center tap of the first coil is directly connected to a surge suppression element and then grounded.

4. The filter circuit according to claim 1, characterized in that: only a surge suppression element and a resistor are connected between the ground point and the center tap of the first coil, and the center tap of the first coil, the resistor, and the surge The suppression element and the ground point are connected in sequence.

5. The filter circuit according to claim 1, wherein the second coil is further provided with a center tap, and the common mode choke coil further comprises a fifth coil connected to the center tap of the second coil.

6. The filter circuit according to claim 5, wherein the fifth coil has two connection ends, one connection end of the fifth coil is connected to the center tap of the second coil, and the other connection end of the fifth coil is connected to a ground after the capacitor.

7. The filter circuit according to claim 1, wherein in the connector, the connection of the center tap to the ground must pass through a surge suppression element.