JPS5930524Y2 - Composite feed-through capacitor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite feed-through type capacitor suitable for use in an antenna input circuit of a TV receiver.

One of the reception disturbances in TV receivers is video disturbances such as ghosts or reflected images caused by reflection of signal radio waves.

This is because there is a difference in signal strength, time, etc. between the signal that enters the receiving antenna and the signal that directly enters the receiver or the signal that reflects from a building etc. and enters the antenna. This is caused by overlapping images.

Furthermore, it is necessary to match the antenna input circuit in order to improve the transmission efficiency as much as possible and at the same time prevent the round trip reflection of signals on the feeder line.

As a solution to these problems, a feedthrough capacitor as shown in FIG. 1 is known.

This through-type capacitor includes a flat ceramic capacitor 7 that has a pair of electrodes 5 and 6 around a through-hole 4 that is open on both sides, inside a cylindrical external terminal fitting 3 that has a through-hole 2 in the bottom part 1. are fixed so that the electrodes 6 are in contact with the bottom part 1, and a cylindrical internal terminal 8 penetrated through the through hole 4 of the ceramic capacitor 7 is inserted into the electrode 5, and the internal terminal 8 and The structure was such that an insulating resin 9 was filled around a ceramic capacitor 7 surrounded by an external terminal fitting 3.

Since the feed-through capacitor described above can directly connect an F-type plug or phono jack to the internal terminal 8, the lead inductance is extremely small, the frequency characteristics are good, and the reflection coefficient is extremely low. Small objects can be realized.

However, since the ceramic capacitor 7 is a single plate type,
There is a limit to the improvement in withstand voltage, and when used for antenna input circuits, it cannot withstand lightning strikes, surge voltages, etc., and there is a risk of fire, electric shock, etc.

In order to prevent fires, electric shocks, etc. that do not compensate for this lack of withstand voltage, conventionally, an RC composite component with a discharge gear is connected in parallel with the feedthrough capacitor 7 to discharge lightning strikes, surge voltage, etc. to the feedthrough capacitor 7. It was designed to be absorbed by the gap.

That is, when constructing a feedthrough capacitor unit for an antenna input circuit using a conventional feedthrough capacitor, for example, as shown in FIG. The feedthrough capacitor 11 screwed into the antenna terminal mold plate 14 is attached to the box-shaped shield case 12, and the shield case 12 and the feedthrough capacitor 11 are connected to the antenna terminal mold plate 14 by the nut 13 screwed into the end of the connecting body 10. Fix it on top.

A connection body 15 is attached to the other face plate of the shield case 12, and a connection body 10 is connected to the center conductor 16a of the coaxial cable 16 guided into the shield case 12 via the connection body 15. In this case, two RC composite parts 17 and 18 having a discharge gap d1 are connected in series.

The RC composite parts 17 and 18 with discharge gears are provided to protect the coupling capacitor C1 from abnormal voltages such as lightning strikes and surge voltages. Even if it is destroyed by voltage, as long as other components are healthy, it is possible to prevent destruction of the coupling capacitor C1, fire, electric shock, etc., so it is designed as a safety measure with a double protection insulation structure, and complies with safety standards. matches.

Furthermore, in order to absorb abnormal voltages such as lightning strikes and surge voltages to the through-type capacitor 11, an RC composite component 19 with a discharge gear similar to that described above is connected between the connecting body 15 and the external terminal fitting 3. Ta.

As mentioned above, when using a conventional feed-through capacitor, in order to protect its function as a bypass capacitor from abnormal voltages, it is necessary to protect it from surges such as RC composite parts with discharge gears from the standpoint of double protection insulation. Although it is essential to provide absorbing parts, there is a drawback that the number of parts is large, leading to an increase in overall size and cost.

This invention eliminates the above-mentioned drawbacks, has a very high withstand voltage,
Even if it is partially destroyed by lightning strikes, surge voltage, etc.
We have created a safe, highly reliable, small, and inexpensive composite feed-through type capacitor that has a double protective insulation structure that can secure its function as a bypass capacitor and completely prevent fires and electric shock accidents. The purpose is to provide.

In order to achieve the above object, a composite feedthrough capacitor according to the present invention includes a flat ceramic capacitor having electrodes around a through hole opened on both sides, and a flat ceramic capacitor inserted into the through hole of the ceramic capacitor, a cylindrical ceramic capacitor having an outer circumferential electrode and an inner circumferential electrode electrically connected to one of the electrodes; an internal terminal passing through the inner diameter of the ceramic capacitor and electrically conducting to the inner circumferential electrode; and the ceramic capacitor assembly. and an insulating resin filled around the ceramic capacitor assembly in the external terminal fitting.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The content of the present invention will be specifically explained in detail below with reference to the accompanying drawings, which are examples.

FIG. 3 is an exploded perspective view of the composite penetrating type container according to the present invention, and FIG. 4 is an assembled cross-sectional view.

In the figure, 21 is an external terminal fitting having a through hole on at least one surface.

In this embodiment, it is formed into a stepped cylindrical shape with a through hole 22 in the bottom surface 21H.

23 is an electrode 25 around a through hole 24 opened on both sides.
．． This is a flat plate-shaped porcelain container having 26 parts.

The through hole 24 is not limited to a circular shape, but may have other shapes.

The electrode 25 is formed in an annular shape with a gap g1 away from the edge of the through hole 24, and the electrode 26 is formed in a circle approximately continuous with the edge of the through hole 24 and inward from the outer periphery by a gap g2. It has a circular shape.

This ceramic capacitor 23 has an electrode 25 connected to an external terminal fitting 2.
1, and is fixed by means such as soldering.

27 is a cylindrical ceramic capacitor having an outer circumferential electrode 28 and an inner circumferential electrode 29.

In this embodiment, the ceramic capacitor 27 is formed into a cylindrical shape with a slightly smaller diameter than the inner diameter of the through hole 24 of the ceramic capacitor 23, and an outer circumferential electrode 28 is provided in the axially intermediate portion with a gap g32g4 from both end faces. be.

Further, the inner peripheral electrode 29 is provided on substantially the entire surface of the inner diameter portion.

Reference numeral 30 denotes an electrode connecting body made of a metal material, which functions to conductively connect the outer peripheral electrode 28 to the electrode 26 in a state where the ceramic capacitor 27 is fitted into the through hole 24 of the magnetic capacitor 23.

In this embodiment, the electrode connector 30 is configured as a cylindrical body with a flange having a notch 31 in the middle, and uses its elastic force to bring the outer electrode 28 into close contact with the inside of the cylindrical portion 30a.
The structure is such that the flange portion 30b is brought into contact with and electrically connected to the electrode 26 of the ceramic capacitor 23.

It is desirable that the electrode connector 30, the outer peripheral electrode 28, and the electrode 26 be connected and fixed using solder, conductive paste, or the like.

Reference numeral 32 denotes an internal terminal fitted into the inner diameter portion of the ceramic container 27.

In this embodiment, the cylindrical body has a flange 32a, and the cylindrical part 32b is fitted into the inner diameter of the ceramic capacitor 27 while the flange 32a is positioned by contacting one end surface of the ceramic capacitor 27. , and are electrically connected to the inner peripheral electrode 29.

It is preferable that the inner terminal 32 and the inner peripheral electrode 29 be fixed to each other by solder or conductive paste. Reference numeral 33 is a connector terminal fitted into the inner diameter of the inner terminal 32.

This connector terminal 33 can also be used also by the internal terminal 32.

Reference numeral 34 denotes an insulating resin filled around the ceramic containers 23 and 27 to ensure insulation, moisture resistance, etc., and is made of, for example, epoxy resin.

The composite feed-through type capacitor according to the present invention has the above-described structure, and as shown in FIG.
Since it is a composite type in which the feed-through capacitor C2 according to the above and the feed-through capacitor C3 formed by the magnetic capacitor 23 are formed together between the internal terminal 32 and the external terminal fitting 21, there is no connection between the internal terminal 32 and the external terminal fitting 21. The voltage applied to the capacitors 23 and 27 will be shared by the magnetic capacitors 23 and 27.

As a result, the withstand voltage becomes extremely high, and reliability against lightning strikes, surge voltages, etc. is significantly improved.

Furthermore, even if one of the ceramic capacitors 23 or 27 is destroyed, the remaining capacitors can still provide the necessary insulation and capacity, resulting in a double protective insulation structure, ensuring safety and Reliability will be extremely high.

Furthermore, as shown in the embodiment, since the structure is such that the cylindrical ceramic capacitor 27 is inserted into the through hole 24 of the ceramic capacitor 23, positioning and assembly of both are extremely easy, and at the same time, mechanical strength is improved. A large container assembly structure is obtained.

Further, since a cylindrical ceramic capacitor 27 having an outer peripheral electrode 28 and an inner peripheral electrode 29 is used, the electrode area can be significantly increased compared to a flat ceramic capacitor or the like.

For this reason, the thickness of the dielectric ceramic element constituting the ceramic capacitor 27 is increased, and while the withstand voltage characteristics are improved,
The decrease in acquisition capacity due to the thickening of the dielectric ceramic body is compensated for by increasing the electrode area of the outer circumferential electrode 28 and the inner circumferential electrode 29, thereby creating a feed-through capacitor that improves withstand voltage characteristics while securing the necessary acquisition capacity. It is possible to achieve this.

Furthermore, by forming the ceramic capacitor 27 into a cylindrical shape having an outer circumferential electrode 28 and an inner circumferential electrode 29, the inner terminal 33 penetrating through the inner diameter thereof is shielded by the outer circumferential electrode 28 and the inner circumferential electrode 29. The anti-ghost effect is improved.

FIG. 6 shows a feedthrough capacitor unit for an antenna input circuit constructed using the composite feedthrough capacitors shown in FIGS. 3 and 4. FIG.

In this embodiment, the composite feedthrough capacitor 37 is mounted inside a box-shaped shield case 36 mounted on the antenna terminal mold plate 35, and the center of the coaxial cable 38 led from the antenna is placed inside the inner diameter of the connector terminal 33. conductor 3
8a is fitted, and a coupling capacitor part 40 with a discharge gear is connected in series between the center conductor 38a and the tuner side connector 39.

A plurality of coupling capacitor components 40 are connected in series, so that even if the discharge gap of one coupling capacitor component malfunctions, the discharging operation can be performed by the discharge gaps provided in the other coupling capacitor components. It may also be configured to ensure.

As is clear from the above examples, the composite feedthrough type capacitor according to the present invention has a very high withstand voltage, and the
Since it has a heavy protection insulation structure, it is an RC with a discharge gear knob to protect this composite feedthrough capacitor from surge voltage, etc.
Composite parts etc. are not required, the number of parts is small, and a small and inexpensive feed-through capacitor unit can be realized.

FIG. 7 shows a sectional view of another embodiment of the composite feedthrough capacitor according to the present invention.

The feature of this embodiment is that the external terminal fitting 42 is box-shaped and doubles as a shield case, thereby reducing the number of parts and the number of processing and assembly steps, making it possible to reduce the overall size and cost.

As described above, the composite feedthrough capacitor according to the present invention includes a flat ceramic capacitor having electrodes around a through hole that is open on both sides, and a flat ceramic capacitor that is inserted into the through hole of the ceramic capacitor. , a cylindrical ceramic capacitor having an outer circumferential electrode and an inner circumferential electrode electrically connected to one of the electrodes, an internal terminal passing through the inner diameter of the ceramic capacitor and electrically conducting to the inner circumferential electrode, and the ceramic capacitor assembly. The present invention is characterized by comprising: an external terminal fitting having a built-in solid body and electrically connected to the other electrode of the flat ceramic capacitor; and an insulating resin filled around the ceramic capacitor assembly within the external terminal fitting. This has the following effects:

(1) Withstand voltage characteristics are significantly improved, and reliability against lightning strikes and surge voltages is extremely high.

(2) Since it has a double protective insulation structure, even if one of the magnetic capacitors is destroyed by a lightning strike or surge voltage, the necessary insulation and capacity will be ensured by the other healthy magnetic capacitor.

As a result, fires, electric shocks, etc. are completely prevented, and safety and reliability are significantly improved.

(3) Since the withstand voltage is extremely high and the double protection insulation structure is used, surge protection measures such as RC composite parts with discharge gears are required when used as a feed-through capacitor for the antenna input circuit. Therefore, it is possible to realize a small and inexpensive feed-through capacitor unit with a small number of parts.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional feedthrough capacitor, Fig. 2 is a sectional view of a feedthrough capacitor unit for an antenna input circuit using this feedthrough capacitor, and Fig. 3 is a sectional view of a composite feedthrough capacitor according to the present invention. 4 is an exploded perspective view, FIG. 4 is an assembled sectional view, FIG. 5 is an equivalent circuit diagram, and FIG.
The figure is a sectional view of a feedthrough capacitor unit for an antenna input circuit constructed using the composite feedthrough capacitor according to the present invention, and FIG. 7 is a sectional view of another embodiment of the composite feedthrough capacitor according to the present invention. be. 21...External terminal fitting, 27...Magnetic capacitor, 23...Magnetic capacitor, 28...
...Outer electrode, 24...Through hole, 29.
...Inner circumferential electrode, 25.26...Electrode, 3
2...Internal terminal.

Claims (4)

[Scope of utility model registration request] (1) A flat ceramic capacitor having electrodes around a through hole opened on both sides, an outer peripheral electrode and an inner peripheral electrode that are inserted into the through hole of the ceramic capacitor and electrically connected to one of the electrodes. A cylindrical ceramic capacitor having an electrode, an internal terminal that passes through the inner diameter of the ceramic capacitor and is electrically connected to the inner circumferential electrode, and the ceramic capacitor assembly is built in, and the flat ceramic capacitor assembly is built in. A composite through-type capacitor comprising: an external terminal fitting in which the other electrode of the flat ceramic capacitor is electrically connected; and an insulating resin filled around the ceramic capacitor assembly within the external terminal fitting. . (2) The flat ceramic capacitor is fixed on the negative surface of an external terminal fitting having a through hole on at least one surface, with the other electrode facing the negative surface. A composite penetrating type container according to claim 1 of the utility model registration claim. (3) One of the electrodes of the flat ceramic capacitor and the outer peripheral electrode of the cylindrical ceramic capacitor are electrically connected by an electrode connector fitted to the outer periphery of the cylindrical ceramic capacitor. A composite feedthrough capacitor according to claim 1 or 2 of the utility model registration claim. (4) The composite through-type capacitor according to claim 1, 2, or 3 of the utility model registration claim, wherein the cylindrical ceramic capacitor includes an internal terminal fitted into the inner diameter part. Container.