CN103366953B - High voltage discharge protection device and radio frequency transmission equipment - Google Patents

Abstract

The invention discloses a high-voltage discharge protection device and radio frequency transmission equipment, wherein the high-voltage discharge protection device comprises an isolation capacitor (2) arranged at a signal port of the radio frequency transmission equipment and a circuit board (1) provided with the isolation capacitor (2), the isolation capacitor (2) comprises a capacitor main body (21) and a pin (22) connected with the capacitor main body (21), the pin (21) is connected to the circuit board (1), the bottom of the capacitor main body (21) is exposed, and an interval is formed between the exposed part of the capacitor main body (21) and the circuit board (1); the high-voltage discharge protection device also comprises a grounded metal conductor (3), wherein the metal conductor (3) is arranged in the interval and is separated from the exposed part by a certain distance. The high-voltage discharge protection device has small volume and low cost, can isolate direct current and couple radio frequency, and gives consideration to discharge protection.

Description

High voltage discharge protection device and radio frequency transmission equipment

technical field

The invention relates to a radio frequency transmission device, in particular to a high voltage protection device for radio frequency transmission equipment.

Background technique

The anti-high voltage protection of the signal port of the radio frequency transmission equipment in the existing radio and television industry is usually realized by devices such as discharge tubes and overcurrent inductors. However, in recent years, with the increasing competitive pressure of radio frequency transmission equipment, the development of radio frequency transmission equipment is required to be low-cost and miniaturized. Existing devices such as discharge tubes and large overcurrent inductors have many shortcomings. High; Second, the large volume of the device takes up a lot of space.

Contents of the invention

The technical problem to be solved by the present invention is to provide an improved high voltage discharge protection device and radio frequency transmission equipment.

The technical solution adopted by the present invention to solve the technical problem is to provide a high-voltage discharge protection device, including an isolation capacitor arranged at the signal port of the radio frequency transmission equipment and a circuit board on which the isolation capacitor is installed, and the isolation capacitor includes a capacitor body and two pins connected to the capacitor body, the two pins are connected to the circuit board, the bottom of the capacitor body is exposed, and a space is formed between the exposed part of the capacitor body and the circuit board The high-voltage discharge protection device also includes an at least partially exposed and grounded metal conductor, the metal conductor is arranged in the interval, and is opposite to the exposed part, and the exposed part is applied to the isolation capacitor When the voltage reaches a certain value, the metal conductor spark discharges.

Further, the isolation capacitor is a chip capacitor, which includes a chip dielectric, two chip electrodes and a cladding layer respectively arranged on the dielectric, two opposite surfaces, the two pins and the two The sheet electrodes are electrically connected, the covering layer covers the sheet dielectric and the upper parts of the two sheet electrodes, and the sheet dielectric and the lower parts of the two sheet electrodes are exposed.

Further, the isolation capacitor is a ceramic capacitor, and the dielectric is a ceramic chip.

Further, the metal conductor includes a bare main body, and the main body is opposite to the exposed bottom of the capacitor main body.

Further, the metal conductor is installed across the bottom of the capacitor body.

Further, the distance between the metal conductor and the exposed part of the capacitor body is less than 2mm.

The present invention also provides a radio frequency transmission device, including a port circuit arranged in the signal port, the port circuit includes an isolation capacitor, the isolation capacitor includes a capacitor body and two pins connected to the capacitor body, the capacitor body including an exposed part; the port circuit further includes an at least partly exposed and grounded metal conductor, the metal conductor is spaced opposite to the exposed part, and the exposed part is sensitive to the isolated capacitor when the voltage applied to the isolation capacitor reaches a certain value The metal conductor spark discharge.

Further, the port circuit includes a circuit board, the two pins are connected to the circuit board, the exposed part is located at the bottom of the capacitor body, and a space is formed between the exposed part and the circuit board, The metal conductor is disposed in the space.

Further, the isolation capacitor is a chip capacitor, which includes a chip dielectric, two chip electrodes and a cladding layer respectively arranged on two opposite surfaces of the dielectric, and the two pins are connected to the two chips. The electrodes are electrically connected, the covering layer covers the sheet dielectric and the upper parts of the two sheet electrodes, and the sheet dielectric and the lower parts of the two sheet electrodes are exposed.

Further, the distance between the metal conductor and the exposed part of the capacitor body is less than 2mm.

The beneficial effect of the present invention is that: the high-voltage discharge protection device in the present invention transforms the isolation capacitor of the port circuit so that the bottom of the capacitor body is exposed, and a grounded metal conductor is arranged between the exposed part and the circuit board, In order to realize high-voltage discharge protection, the cost is low, the space occupied is small, and the assembly is easy.

Description of drawings

The present invention will be further described below in conjunction with accompanying drawing and embodiment, in the accompanying drawing:

Fig. 1 is a schematic structural view of a high-voltage discharge protection device in a preferred embodiment of the present invention;

Fig. 2 is a schematic structural diagram of the isolation capacitor in Fig. 1;

Fig. 3 is a cross-sectional view of the isolation capacitor A-A in Fig. 2;

Fig. 4 is a schematic diagram of the high voltage discharge protection device of the present invention.

detailed description

In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation manners of the present invention will now be described in detail with reference to the accompanying drawings.

As shown in Fig. 1, the high-voltage discharge protection device in a preferred embodiment of the present invention can be used in cable television, and is installed at the signal port of radio frequency equipment, mainly used for isolating DC, coupling radio frequency, and also taking into account the protection of high-voltage discharge. The device includes an isolation capacitor 2, a circuit board 1 and a metal conductor 3, the isolation capacitor 2 is fixedly connected to the circuit board 1, and the metal conductor 3 is grounded.

The isolation capacitor 2 includes a pin 22 and a capacitor body 21, the isolation capacitor 2 is fixed on the circuit board 1 through the pin 22, and the circuit board 1 and the isolation capacitor 2 are installed at the input terminal of the signal port of the radio frequency equipment. The lower part of the capacitor main body 21 is exposed, and when it is installed on the circuit board 1, there is a gap between the exposed part and the circuit board 1, and the metal conductor 3 is installed in the gap, and the exposed part of the metal conductor 3 and the capacitor main body 21 relatively.

Referring to Fig. 2 and Fig. 3 together, the main body of the capacitor includes a cladding layer 211, an electrode 212 and a dielectric 213, the electrode 212 is installed on both sides of the dielectric 213, the cladding layer 211 wraps a part of the electrode 212 and the dielectric 213, and also exposes a part , in this embodiment, the exposed portion is disposed at the bottom of the capacitor main body 21 .

Preferably, the preferred scheme for the electrodes 212 to be exposed is that both electrodes 212 are exposed, because the discharge is between the two electrodes 212, and if only one is exposed, the discharge voltage will be increased.

In this embodiment, the capacitor body 21 is in the shape of a sheet, the electrode 212 is in the shape of a sheet, and the dielectric 213 in the capacitor body 2 is a ceramic chip. It is understandable that in some other embodiments, the dielectric 213 can also be other Made of material.

Since the isolation capacitor 2 is required to have a high-voltage discharge function, it is preferably a chip capacitor. In some other embodiments, the isolation capacitor 2 can be other types of capacitors, such as SMD capacitors.

As shown in FIG. 1 , the metal conductor 3 includes a main body, and bending parts bent in the same direction are respectively provided at both ends of the main body, and the metal conductor is installed under the capacitor body 21 across the two bending parts On the circuit board 1, it can be understood that in some other embodiments, the metal conductor 3 can also be designed in other shapes, so as to achieve the purpose of the capacitor main body 21 to discharge its sparks.

The main part of the metal conductor 3 is exposed, and the exposed part corresponds to the exposed bottom part of the capacitor main body 21. There is a certain gap between the main part of the metal conductor 3 and the exposed part of the capacitor main body 21. In this embodiment, the metal conductor 3. The distance from the exposed part of the capacitor body 21 is less than 2mm.

The design of less than 2 mm is adopted to avoid excessive energy accumulation of the isolation capacitor 2, and the closer distance can release the energy earlier to avoid damaging the components. When the isolation capacitor 2 is discharged, a considerable part of the energy is discharged to the metal conductor 3, and the metal conductor 3 functions to disperse the energy. Therefore, the closer the distance between the metal conductor 3 and the isolation capacitor 2 is, the better. According to test calculations, when the distance exceeds 2 mm, the spark voltage is too high and the device is easily damaged.

Refer to Figure 4 together, the first port in the figure is the port of the radio frequency device, the isolation capacitor 2 (C in the figure) is connected in the circuit of the first port, and the isolation capacitor 2 is directly facing the ground to set the metal conductor 3, the second of the external device The port is connected to the first port; when a high voltage is generated at the first port, the isolation capacitor 2 will spark discharge the metal conductor 3 because of its unique partially exposed structure, and the energy will be absorbed by the metal conductor 3 and transmitted directly into the ground, thereby protecting the second port and the external devices behind it.

With this structure, compared with the discharge protection achieved by arranging a discharge tube or a device with a large overcurrent inductance at the input port of the video equipment, a grounded bare metal conductor 3 is passed through the bottom of the isolation capacitor 2 in this embodiment. The metal conductor 3 is arranged on the exposed bottom of the capacitor body 21 opposite to the circuit board 1. This arrangement basically does not increase the original space, and can protect the product from being damaged by high voltage and high current, so that the circuit board 1 can be better. The arrangement and design of the invention can make the product smaller; and the invention greatly reduces the cost.

When the voltage rises to a certain value, a spark discharge is generated at the exposed bottom position to release energy in advance. Ordinary capacitors need to accumulate very high energy before they can be sparked and discharged. At this time, the capacitor chip has been broken down or broken, the circuit will be destroyed, and the function will be lost.

The structure of the device is simple, and the high-voltage discharge protection function realizes the absorption of high-voltage energy by using the metal conductor 3 . In addition, the device also has the advantages of long life and not easy to be damaged.

In addition, the isolation capacitor 2 still has the functions of isolating DC and coupling radio frequency. The specific principle is: because high-frequency signals belong to AC signals, the capacitor presents low impedance characteristics to AC signals. The higher the frequency, the smaller the impedance. Therefore, the cable TV ( 5MHz-3000MHz) The impedance of the high-frequency signal passing through the capacitor is almost negligible. However, the isolation capacitor 2 presents an impedance of ∞ to the direct current and cannot pass through it.

As another solution, the radio frequency transmission device includes a port circuit, the port circuit includes an isolation capacitor 2, the isolation capacitor 2 includes a capacitor body 21 and two pins 22 connected to the capacitor body 21, the capacitor body 21 includes a bare part. The port circuit also includes an at least partly bare and grounded metal conductor 3, the metal conductor 3 is opposite to the bare part at intervals, and the bare part is opposite to the metal conductor when the voltage applied to the isolation capacitor 2 reaches a certain value. 3 spark discharge.

In this embodiment, the isolation capacitor 2 is a chip capacitor, and the isolation capacitor 2 includes a chip dielectric 213, an electrode 212, and a coating layer 211. The electrode is a chip electrode 212, and the two electrodes 212 are respectively arranged on the dielectric 213. On the two opposite surfaces, the two pins 22 are electrically connected to the two sheet electrodes 212. The cladding layer 211 covers the sheet dielectric 213 and the top of the two sheet electrodes 212. The sheet dielectric 213 and the two The lower part of the sheet electrode 212 is exposed.

In this embodiment, the distance between the metal conductor 3 and the exposed part of the capacitor body 21 is less than 2 mm. The design of the smaller than 2 mm is used to prevent the isolation capacitor 2 from accumulating too much energy, and the energy can be released earlier if the distance is close. , to avoid damaging components. When the isolation capacitor 2 is discharged, a considerable part of the energy is discharged to the metal conductor 3, and the metal conductor 3 functions to disperse the energy.

In this embodiment, a grounded exposed metal conductor 3 is passed through the bottom of the isolation capacitor 2, and the metal conductor 3 is opposite to the exposed bottom of the capacitor body 21. This setting basically does not increase the original space (generally at the signal port of the radio frequency device or device There will be an isolation capacitor itself), and it can protect the product from being damaged by high voltage and high current, which can make the product smaller and greatly reduce the cost.

The above descriptions are only preferred implementations of the present invention, and the scope of protection of the present invention is not limited to the above-mentioned embodiments, and all technical solutions under the idea of the present invention belong to the scope of protection of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims (10)

1. A high-voltage discharge protection device, comprising an isolation capacitor (2) arranged at a signal port of a radio frequency transmission device and a circuit board (1) installing the isolation capacitor (2), said isolation capacitor (2) comprising a capacitor body ( 21) and two pins (22) connected with the capacitor body (21), the two pins (22) are connected on the circuit board (1), it is characterized in that the capacitor body (21) The bottom of the capacitor body (21) is exposed, and a space is formed between the exposed part of the capacitor body (21) and the circuit board (1); the high-voltage discharge protection device also includes a metal conductor (3) that is at least partially exposed and grounded, so The metal conductor (3) is arranged in the gap and is spaced opposite to the exposed part, and the exposed part discharges sparks on the metal conductor (3) when the voltage applied to the isolation capacitor reaches a certain value . 2. The high-voltage discharge protection device according to claim 1, characterized in that, the isolation capacitor is a chip capacitor, which includes a chip dielectric (213), and is respectively arranged on two opposite surfaces of the dielectric (213). Two sheet electrodes (212) and a coating layer (211), the two pins (22) are electrically connected to the two sheet electrodes (212), and the coating layer (211) connects the The upper parts of the sheet-like dielectric (213) and the two sheet-like electrodes (212) are covered, and the lower parts of the sheet-like dielectric (213) and the two sheet-like electrodes (212) are exposed. 3. The high voltage discharge protection device according to claim 2, characterized in that, the isolation capacitor (2) is a ceramic capacitor, and the dielectric (213) is a ceramic chip. 4. The high-voltage discharge protection device according to claim 3, characterized in that, the metal conductor (3) includes a bare main body, and the main body is opposite to the exposed bottom of the capacitor main body (21). 5. The high-voltage discharge protection device according to claim 4, characterized in that, the metal conductor (3) is installed across the bottom of the capacitor main body (21). 6. The high-voltage discharge protection device according to any one of claims 1-5, characterized in that the distance between the metal conductor (3) and the exposed part of the capacitor body (21) is less than 2mm. 7. A radio frequency transmission device, comprising a port circuit arranged in a signal port, said port circuit comprising an isolation capacitor (2), said isolation capacitor (2) comprising a capacitor body (21) and being connected to the capacitor body (21) two pins (22), characterized in that, the capacitor body (21) includes a bare part; the port circuit also includes at least partially bare and grounded metal conductors (3), the metal conductors (3) Opposite to the exposed part, the exposed part sparks and discharges the metal conductor (3) when the voltage applied to the isolation capacitor (2) reaches a certain value. 8. The radio frequency transmission device according to claim 7, characterized in that, the port circuit comprises a circuit board (1), the two pins (22) are connected to the circuit board (1), and the exposed Part is located at the bottom of the capacitor main body (21), a space is formed between the bare part and the circuit board (1), and the metal conductor (3) is arranged in the space. 9. The radio frequency transmission device according to claim 8, characterized in that, the isolation capacitor (2) is a chip capacitor, which includes a chip dielectric (213), which is respectively arranged on two opposite surfaces of the dielectric (213) The two sheet electrodes (212) and the coating layer (211) on the top, the two pins (22) are electrically connected with the two sheet electrodes (212), and the coating layer (211) The upper parts of the sheet dielectric (213) and the two sheet electrodes (212) are covered, and the lower parts of the sheet dielectric (213) and the two sheet electrodes (212) are exposed. 10. The radio frequency transmission device according to claim 9, characterized in that the distance between the metal conductor (3) and the exposed part of the capacitor body (21) is less than 2mm.