JPH0433276A - Contact with filter - Google Patents

Abstract

PURPOSE: To compactify by providing a signal conductor provided with two end parts, an inductor-resistor element connected to the signal conductor, an earth conductor, a diode connected between the signal conductor and the earth conductor, and a capacitor connected between the signal conductor and the earth conductor. CONSTITUTION: In a pin type signal conductor 54, a front part 70 is formed, and a capacitor 68 and an inductor 64 are arranged in the front part 70 of the signal conductor 64. A supporting part 74, to which the signal conductor 54 or a diode 76 is installed, is formed in a central part, 72. An earth conductor 80 is brought into contact with an external terminal of the capacitor 68 and one terminal of the diode 76 so as to earth both of them, while no contact is made between the earth conductor 80 and the inductor 64. The earth conductor 80 is provided with a front sleeve part 82, which surrounds the capacitor 68, and a finger part 84 touching the diode 76. Faces 88, 86 of the diode 76 are soldered to the supporting part 74 for the signal conductor 54 and to the finger part 84 in the earth conductor 80. The capacitor 68 is soldered to the signal conductor 54 and to the front sleeve part 82 in the earth conductor 80. In this way, a contact structure can be compactified as a whole, and its replacement can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a connector and a contact structure attached thereto, and particularly relates to a contact structure incorporating a filter.

BACKGROUND OF THE INVENTION In many applications, contact structures dissipate high-energy electromagnetic pulses or electrostatically induced high voltage pulses to ground, and filter unwanted frequency signals induced by electromagnetic energy in the surrounding environment. It is desirable to remove it. Such undesired signals are generally E
MP (electromagnetic pulse), ESD (electrostatic discharge), E
They are called MI (electromagnetic interference) and RFI (radio frequency interference), and these are collectively called EMX. Diodes and capacitive or capacitive-inductive filters are EMX
are connected to the contacts of the connector to eliminate the effect, resulting in relatively complex contact structures, increasing their cost, and making them bulky and unwieldy. Large, difficult-to-handle contact structures that fail through long, narrow holes in the connector (due to mechanical or electrical failure)
It is difficult to pull out a new one and insert a new one in its place.

U.S. Pat. No. 4,747,789 describes a connector having a diode and a filter connected to a signal conductor, but the device, particularly the filter, is large and unwieldy, and its diameter is the same as that of the signal conductor. and cannot be replaced as easily as simple signal contacts such as those described in U.S. Pat. No. 4,746,310.

The signal contact described in U.S. Pat. No. 4,748,310 is intended to be of relatively compact construction, in which the diode is placed in a cutout recess in the signal conductor; The inductor consists of a ferrite sleeve surrounding the signal conductor. However, this connector requires two large capacitors that are not part of the contact structure, so replacing the contact structure does not involve replacing the capacitors.

[Problem to be Solved by the Invention] A contact with a compact overall contact structure including a filter and a suppression element, which minimizes the number of parts and can obtain effective filtering effects and transient phenomenon suppression effects. It is important that the structure be slender and robust so that it can be easily inserted into and removed from the small diameter hole of the connector for replacement in the position of use.

[Means and effects for solving the problem 1 of this invention! In case B, a contact structure with a relatively simple and compact configuration is provided.

This contact structure comprises a signal conductor, which carries a diode, an inductor, and a capacitor of II.

One terminal of the diode and the capacitor are grounded. A nearly balanced π-type filter is connected to the inductor and ji
ll capacitor and the diode capacitance.

Preferably, the diode is placed on the opposite side of the inductor from the j@1 capacitor and has a capacitance approximately equal to the first capacitor. The inductor is a sleeve or bead of ferrite that surrounds a portion of the signal conductor. On the other hand, the first capacitor is also sleeve-shaped and surrounds the signal conductor.

The grounding conductor includes a sleeve-like portion surrounding and connected to the first capacitor, and a portion extending beyond the ferrite bead without contacting it, and a finger extending into contact with the surface of the diode. It has a shaped part. The notched portion of the signal conductor that holds the diode and the adjacent portion of the contact structure are filled with a flowable, hardening plastic material such as epoxy, which has a generally cylindrical shape to allow insertion of the contact structure into the narrow hole of the connector. It forms the central part of the contact structure.

The features of this invention are described in the claims. The invention will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a connector 10 mounted on a plate 12 with an electrically grounded mounting. Connector 10 comprises a housing 11 having a metal shell 14 which is secured to plate 12 by means of fixing nuts 16. A plurality of contact structures 2o are mounted within the metal shell 14 in a front insulator 22, a rear insulator 24, and an eyelet 2B backing up the rear insulator 24. A surface seal 28 seals the front of the contact, and a surface seal 28
The periphery of is sealed by a peripheral seal 30. Metal ground plane 32 is electrically connected to metal shell 14 by outer ground spring 34 and to contact structure 20 by inner ground spring 36 at ground conductor 80 . The rear portion 40 of the contact structure 20 is connected to a number of contact structures that transmit electrical signals via conductors (not shown). Contact structure 20 is retained in the connector by a retaining clip 42 that contacts a shoulder 44 of contact structure 20. Contact structure 20 can be replaced in the field of use by an extraction tool that spreads the fingers of retaining clip 42 and pulls contact structure 20. The new contact structure 20 is inserted into the bore 46 by moving the contact structure 20 forwardly in the narrow generally cylindrical bore 46 of the connector until the retaining clip 42 resiliently engages the rear of the shoulder 44 of the contact structure 20. can be installed on the device.

FIG. 3 is a circuit diagram of the contact structure, in which the signal conductor 54
It has a front end 50, a rear end 52, and a ground terminal 56 (for transmitting signals and/or current for powering the device). In many applications, it is desirable to protect contact structures against EMP (electromagnetic pulse), which creates high voltages in the signal conductors, and EMI (electromagnetic interference), which creates unwanted high frequency signals in the signal conductors. High voltages can be avoided by a diode 60, such as a Zener diode, either unipolar or bipolar depending on the protection purpose. Both ends 88 and 88 of the diode 60 are connected to the ground terminal 56 and the signal conductor 5, respectively.
Connected to 4. The EMI filter 62 is a low-pass filter that passes only signals lower than a predetermined frequency.
avoided by

The most effective and simple filter is the balanced π-type filter,
It comprises an inductor 64 coupled to the signal conductor 54 and two capacitors 66.6B connected between the signal conductor 54 and the ground terminal 56 at both ends of this inductor B4. The best results were obtained when the filters were balanced, with the capacitances of the 2 m capacitors 66, 68 being substantially equal. Even better results were obtained by placing a resistor between one end of the inductor 64 and one terminal of one of the capacitors 88, 88, as explained below. By using the capacitance of diode 60 as one of the capacitors and making it equal to the capacitance of the other capacitor, the number of capacitors included in the contact structure can be minimized.

The overall diode with diode function and predetermined capacitance is shown as 76 in the figure. Both ends 87, 89 of the first capacitor are connected to ground terminal 56 and signal conductor 54, respectively. It is also possible to use only a resistive element instead of the inductor 64 or an inductor and a resistive element, but in this case losses will increase. Therefore, the components used for the inductor 64 are preferably an inductor and a resistance element.

4 and 5 show contact structure 20 in detail. For convenience of explanation, the illustrated direction F is considered to be forward.

However, the opposite direction may be the front.

The signal conductor 54 has a front portion 70 formed in the form of a pin with a cylindrical outer surface of small diameter. first capacitor 6
8 is a bead capacitor, the inductor 64 is a ferrite bead, and both annular devices are provided in the front portion 70 of the signal conductor 54. The signal conductor 54 also has a central portion 72 formed with a cut-out recess 73 having a support portion 74 in which a diode 76 is mounted. The grounding conductor 80 is in contact with the outer terminal of the first capacitor 68 and one terminal of the diode to ground them both (
(by the grounding spring 3B in Fig. 1). However, ground conductor 80 does not contact inductor 64 . The ground conductor 80 includes a front sleeve portion 82 that surrounds the first capacitor 68 and a rearwardly extending finger portion 84 that contacts the diode. Both sides 88.88 of the diode are soldered to the support portion 74 of the signal conductor 54 and to the fingers 84 of the ground conductor 80. First capacitor 68
has its radially inner and outer surface terminals and is mechanically and electrically connected to the front sleeve portion 82 of the signal conductor 54 and ground conductor 80 by soldering. The ferrite bead inductor 64 is configured such that its inside is in close contact with the contact portion 70 for a tight coupling thereto (ferrite bead inductor B4 is not mechanically or electrically connected in series with the signal conductor, but
physical location on a signal conductor that produces a desired electrical effect).

Diode 7B, inductor 64, first capacitor 6
B, and after the ground conductor 80 is installed on the signal conductor 54, a flowable, curable polymeric material 9, such as an epoxy.
It is preferred to seal them by 0. The intermediate portion 72 of the signal conductor 54 with the attached diode 7B is placed in a generally cylindrical mold and epoxy is poured into the mold. The epoxy surrounds diode 76 and fingers 84 and includes a portion 92 that fills recess 73 of signal conductor 54 and a portion 94 that directly surrounds inductor 64 and fills between inductor 64 and an intermediate portion of ground conductor 80. Therefore, the contact structure 20 can be provided with a diode for extinguishing pulses and an effective filter for extinguishing high-frequency currents in a relatively simple and compact structure, which is formed in the connector into which the contact structure 20 is inserted and removed. It can be adapted to fit into narrow holes.

In one embodiment, signal conductor 54 has a front portion with a diameter A of 30 mils (1 mil-1/too inch) and a maximum diameter B portion of 80 mils, and diode 76 has a width and length. Each is 37 mils and 10 mils high.

The capacitance of diode 7B is approximately 2000 picofarads, and the capacitance of the first capacitor B8 is 2000 picofarads. Diode 78 comprises a body of diode material and terminals on both sides thereof; most diodes of this type have a capacitor of 100 picofarads or more.

Inductor 64 has an inductance of 10 microHenries. Diode 7B is a Zener diode with a breakdown voltage of ±6 volts. Inductor 64, first
The filter formed by the capacitor 68 and the capacitance of the diode 76 provides attenuation of 10 denbels at 10 MHz to the signal passing through the signal conductor 54. Substantial attenuation occurs only above about I MHz, so with this design the contact structure is effective for transmitting signals at frequencies up to about I MHz.

A simple π-type filter with a pair of capacitances coupled on either side of an inductor is effective in blocking high-frequency currents, but an even better efficiency is an RLC filter similar to a π-type filter but with a resistor in series with the inductor. obtained by the circuit. FIG. 6 shows a filter circuit 100 of this type, which has a resistor 102 in addition to an inductor 64 (or an alternative inductor), and a diode capacitor 66 representing the capacitance of a first capacitor 68 and a diode 60. have For a filter having capacitance and inductance values as described above, a resistor 102 having a resistance value on the order of 5000 ohms is appropriate. Of course, the signal conductor 54 has a resistance, but it is negligible and the effective filter resistance must be much larger.

FIG. 7 shows a contact structure similar to that of FIG. 4, which includes a resistive element 112 coupled in series to the front and rear portions of a signal conductor 118. Resistive element 112 includes a generally cylindrical dielectric element 115 (FIG. 8) having a resistive layer 117 and a conductive layer 119 DEG 12 (l) on its surface to form resistor 102 (FIG. 6). In the construction of the device, a resistive layer 117 is first deposited on the dielectric element 115, and then conductive layers 119, 12
0 is deposited on both ends of the resistive layer 117 so as to at least partially overlap. The front portion 114 and the rear portion 118 of the signal conductor 118 are formed with holes 122 and 124 into which the ends of the dielectric element 115 fit. Conductive layer 119
, 120 are soldered to portions 114 and 116, respectively, thereby connecting resistive layer 117 to portion 114 of the signal conductor.
, 116, and also provides some mechanical coupling. Ground conductor 80A is similar to that of FIG. 4, but its fingers 84A are made somewhat longer to allow for resistive element 112. After assembling the parts, the structure is sealed with epoxy 90A and the parts are held together, resulting in a generally smooth cylindrical outer surface formed by a flowable, hardened plastic material.

In this manner, the present invention provides a relatively simple and compact contact structure that is robust, low cost, and allows for easy on-the-spot replacement of failed contact structures. The contact structure includes a diode for erasing high voltage pulses, and a filter with a capacitor coupled between an inductor and both sides of the inductor and a ground point, one of which utilizes the capacitance of the diode. be. The inductor and the first capacitor may be comprised of a bead surrounding the cylindrical portion of the signal conductor, while the ground conductor extends closely surrounding the first capacitor but not in contact with the inductor and in contact with the diode. It is formed as a sleeve with finger-like portions for use. The contact structure is then sealed with a flowable hardened plastic material, such as epoxy, along the central portion of the contact structure to hold all parts together and to allow for easy replacement of the contact structure while in use. A substantially cylindrical outer surface is formed.

Although specific embodiments of the present invention have been described above, those skilled in the art can make various modifications and changes without departing from the technical scope of the present invention. therefore,
It should be recognized that various such modifications and equivalents are intended to be included within the scope of the claims.

[Brief explanation of drawings]

FIG. 1 is a partially sectional side view of a connector according to an embodiment of the present invention. FIG. 2 is a front view of the connector of FIG. 1. FIG. 3 is an equivalent circuit diagram of the contact structure of the connector shown in FIG. 1. FIG. 4 is a cross-sectional view of the contact structure of FIG. 1. FIG. 4A is a cross-sectional view taken along line 4A-4A of FIG. FIG. 5 is an exploded perspective view of the contact structure of FIG. 4. FIG. 6 is a circuit diagram of a contact structure according to another embodiment of the invention, which includes a resistor in the filter. FIG. 7 is a cross-sectional view of a contact structure having the circuit of FIG. 8 is a partially exploded perspective view of the contact structure of FIG. 7. FIG. lO... Connector, 12... Mounting is on board, 14...
Metal shell, 20... Contact structure, 54... Signal conductor, 64... Inductor, 8G, H... Capacitor, 7B... Diode. Applicant's agent Patent attorney Takehiko Suzue

Claims (10)

[Claims] (1) A connector comprising a housing and a plurality of filter contact structures in the housing, each contact structure including a signal conductor having first and second ends and an inductor coupled to the signal conductor. A resistive element, a ground conductor, a diode connected between the signal conductor and the ground conductor, and a first capacitor connected between the signal conductor and the ground conductor, the diode being the diode and a first capacitor are connected at positions along the signal conductor on opposite sides of the inductor-resistance element, and the first capacitor has a capacitance substantially equal to the capacitance of the diode. A connector characterized in that it has a capacitance equal to . (2) The first capacitor is a bead-shaped annular element that substantially surrounds the signal conductor, and the diode is connected to the signal conductor on one side of the inductor/resistance element opposite to the first capacitor. wherein the ground conductor surrounds and contacts the first capacitor, and further includes finger-like portions that extend but do not contact the inductor/resistance element and contact the diode. Item 1
Connector listed. (3) a flowable hardening plastic material is filled in the space between the ground conductor and the inductor/resistive element and substantially surrounds the fingers of the ground conductor and the diode and is adhered to the signal conductor; 3. The connector according to claim 2, wherein the ground conductor is held so as to be in contact with the diode without being in contact with the inductor/resistance element. (4) The signal conductor includes a front part, a rear part, and a resistance device that constitutes the inductor/resistance element and connects both parts of the signal conductor with a high ohmic resistance value, and the diode is connected to the signal conductor. 3. The connector of claim 2, wherein the first capacitor is disposed on and connected to one portion of the conductor, and wherein the first capacitor is connected to the other portion of the signal conductor. (5) In a filtered contact structure mounted in a connector housing, a pin-shaped cylindrical front portion;
a signal conductor having a rear portion and a central portion; a bead capacitor closely surrounding and electrically connected to the front portion of the signal conductor; and a bead capacitor closely surrounding and electrically connected to the front portion of the signal conductor behind the capacitor; a bead ferrite element disposed surrounding the capacitor; a diode having a first surface in contact with the central portion of the signal conductor and a second surface opposite to the first surface; and a sleeve-shaped diode closely surrounding the capacitor. a grounding conductor having a front portion, a rear portion formed with fingers in contact with the second surface of the diode, and a central portion extending without contacting the ferrite element; A contact structure characterized by comprising: (6) a flowable hardening plastic material is disposed surrounding the fingers of the ground conductor, the diode, and a central portion of the signal conductor located behind the front portion of the ground conductor; The material forms part of a generally cylindrical outer surface in the central portion of said signal conductor, thereby integrating the parts to facilitate rearward removal of a failed contact structure and forward insertion of a new contact structure. 6. The contact structure according to claim 5, wherein the contact structure is maintained at . (7) In a contact structure mounted in a connector housing, a signal conductor having a front portion and a rear portion, a ferrite bead closely surrounding and coupled to the front portion of the signal conductor, and a grounding conductor. and a first conductor located in the front portion of the signal conductor in front of the ferrite bead and coupled to the signal conductor and the ground conductor, respectively.
and a second capacitance including a diode having first and second terminals on both sides, the diode having a predetermined voltage across its terminals. The diode has a capacitance of several hundred picofarads or more between the two terminals of the diode, and the diode has a capacitance of several hundred picofarads or more between the two terminals of the diode, and the diode has a A contact mounted on the signal conductor, wherein the terminals of the diodes are connected to the signal conductor and the ground conductor, respectively, and the first and second capacitances have substantially equal capacitances. structure. (8) The signal conductor includes a separated front portion and a rear portion, and includes a resistance device that electrically connects both portions of the signal conductor with a predetermined resistance value, and the resistance device includes the 8. The contact structure of claim 7, wherein the contact structure is located between a ferrite bead and one of the capacitors. (9) The ground conductor includes a sleeve-shaped portion surrounding and electrically connected to the bead capacitor, a central ground conductor portion passing in the vicinity of and spaced from the ferrite bead, and a central ground conductor portion of the diode. 8. The contact structure according to claim 7, further comprising a finger-like portion that contacts the terminal. (10) a flowable hardening plastic material is disposed between the diode, the fingers of the ground conductor, the ferrite bead and the central portion of the ground conductor, and at least one of the substantially cylindrical outer surfaces 10. A contact structure according to claim 9 forming a part of the contact structure.