TWM522499U - Surge preventing circuit - Google Patents

Description

Surge protection circuit

The present invention relates to the technical field of electrical connectors, in particular to a surge protection circuit that increases the high voltage surge suppression function by adding a capacitor to the signal receiving end without affecting the transmission quality and function.

In order to facilitate data storage and data exchange among notebook computers, smart phones and tablets, computer operators are equipped with USB electrical connectors in notebook computers, smart phones and tablets, and communication systems. The industry partnered to launch the Cloud Drive service. Therefore, in order to respond to various cloud hard disk services, the communication system operator must increase the number of network servers on the server side or the relay side, thereby increasing the data transmission traffic. Among them, the RJ45 electrical connector is usually installed in the network server to serve as a connection interface between the network server and the Ethernet twisted pair network route.

Please refer to FIG. 1 , which is a conventional RJ45 electrical connector module. As shown in the first figure, a plurality of RJ45 electrical connectors 10' are integrated into a single RJ45 electrical connector module 1', so that the RJ45 electrical connector module 1' can be installed into the network in a modular manner. The server, in this way, simplifies the architecture of the network server and at the same time increases its scalability. In addition, in conjunction with the number of RJ45 electrical connectors 10', the RJ45 electrical connector module 1' is typically provided with a plurality of isolation transformers for performing signal transmission, waveform repair, and high voltage isolation.

Further, please refer to FIG. 2, which is an equivalent circuit diagram of an isolation transformer inside the RJ45 electrical connector module. As shown in FIG. 2, in the case of a plurality of isolation transformers 11' in the general RJ45 electrical connector module, the primary side is coupled to the signal input interface 111' of the RJ45 electrical connector module, that is, the RJ45 is electrically connected. The second side of the isolating transformer 11' is coupled to the signal receiving interface 112', that is, the network physical layer that is electrically connected to the RJ45 electrical connector module (ie, the connecting end of the connecting plug) Physical Layer).

In the conventional technology, the center-tapped (CT) of the primary side of the isolation transformer 11' is coupled with a plurality of matching resistors Im', and the resistance of the matching resistors Im' The value is 75 ohms; thus, the isolation transformers 11' can be impedance matched with the input signals (interfaces) by the arrangement of the resistors; in addition, the resistors are further coupled with a capacitance value of 0.001 μF. A high voltage capacitor C _HV ' is used to couple the bursty high voltage input to ground.

The equivalent circuit diagram inside the above RJ45 electrical connector is widely used in various network electrical connectors or electrical connector modules for the lowest cost and most compact electrical connector circuit. However, the equivalent circuit and transformer components of the isolation transformer described in Figure 2 are only equipped with a high voltage capacitor C _HV ' to couple the sudden high voltage input to the ground; however, the situation often encountered in the practical area Yes, in order to facilitate network wiring considerations, the network cable is often barely placed outside the building; therefore, in the event of a lightning strike, the high-voltage current generated by the lightning strike may be instantaneously transmitted to the network. The data machine or computer on which the cables are connected to each other causes the data machine or the computer motherboard to be burnt due to high voltage current.

That is to say, the equivalent circuit and the transformer component of the foregoing isolation transformer are basically not equipped with an anti-surge protection circuit or related electronic components, so that the equivalent circuit and the transformer component of the above-mentioned isolation transformer have almost no anti-surge The function.

Please refer to FIG. 3, which is a circuit diagram of an isolation transformer inside another RJ45 electrical connector module. In order to make the connector have the function of anti-surge, the current technology shows the isolation transformer circuit diagram shown in FIG. 3, wherein, unlike the circuit architecture of FIG. 2, the designer connects the isolation transformer 11' to the signal input. An autotransformer (AT) is disposed on the primary side of the interface 111', and the central tap of each autotransformer AT is short-circuited to the ground T _GND to achieve high voltage permeable when the surge is generated. The above grounding circuit is designed to guide external voltage and current to the metal casing or the ground, thereby preventing the computer host from being damaged by the instantaneous surge of voltage or current, and realizing the function of line-to-ground protection.

Although the design of the autotransformer grounding circuit shown in FIG. 3 enables the electrical connector to have the function of preventing surge, its practical ability to suppress the strong high voltage surge such as lightning is still limited. Therefore, the circuit diagram of the isolation transformer inside the RJ45 electrical connector module shown in FIG. 4 is further developed. As shown in the figure, different from the above two connector circuit structures, in order to effectively increase the anti-surge function of the connector, the designer is connected to the secondary side of the isolation transformer 11' and the signal receiving interface 112'. That is, the physical side of the circuit is additionally provided with an anti-surge protector P, thereby effectively increasing the anti-surge function of the connector.

Although the anti-surge function of the connector of Fig. 4 has a high anti-surge protection function, the anti-surge protector P has a certain component volume, which often causes the manufacturer to design the internal space of the electrical connector. In addition, the cost of parts of the anti-surge protector P is relatively high, which indirectly leads to an increase in the production cost of the connector and reduces the profit of the actual product.

The inventor of the present invention has invented the invention in view of the above-mentioned internal anti-surge circuit of the conventional electrical connector, and finally researched and developed the surge protection circuit of the present invention.

The purpose of this creation is to provide a surge protection circuit, which is mainly through the way of connecting the snubber capacitor between the isolation transformer of the connector and the physical layer of the network, thereby maximizing the state of the signal transmission quality. The surge protection function, in addition, the design of the series capacitor can also replace the traditional design of the anti-surge protector, which not only reduces the space occupied by the physical circuit, but also reduces the manufacturing cost of the connector.

Therefore, in order to achieve the above object of the present invention, the inventor of the present invention proposes that the surge protection circuit includes at least one filter module, and the filter module includes:

An isolation transformer having a primary side and a secondary side, wherein the primary side is coupled to a network physical layer through two signal output terminals; and a common mode filter coil coupled to a signal receiving interface at one end The other end is coupled to the secondary side of the isolation transformer; and wherein a buffer capacitor is connected in series between the primary side of the isolation transformer and the signal output terminal.

In order to more clearly describe a surge protection circuit proposed by the present invention, a preferred embodiment of the present invention will be described in detail below with reference to the drawings.

Please refer to FIG. 5, FIG. 6a to FIG. 6b and FIG. 7 , which are respectively a circuit diagram of a surge protection circuit, a schematic diagram of a surge voltage guide of the surge protection circuit, and an application exploded view of the surge protection circuit. As shown in FIG. 5, FIG. 6a to FIG. 6b and FIG. 7, a surge protection circuit of the present invention mainly includes a plurality of filter modules, wherein each filter module includes: an isolation transformer 11 and a common mode Filter coil 11a.

Further, the isolation transformer 11 has a primary side and a secondary side, and the primary side is coupled to a network physical layer (not shown) through the two signal output terminals 15, and the common mode filter coil 11a The two signal input terminals 14 are coupled to a signal receiving interface (not shown) and the other end is coupled to the secondary side of the isolation transformer 11. In the prior art, a snubber capacitor 13 is disposed between the primary side of the isolation transformer 11 and the signal output terminal 15.

In addition, in the circuit architecture of the embodiment, each of the filter modules is further connected to an auto-transformer 12, wherein the autotransformer 12 is coupled to the common mode filter coil 11a and the signal. Between the receiving interfaces, the center-tapped (CT) of the autotransformer 12 is designed to be connected to the G.

Moreover, the central tap portion of the primary side of the isolation transformer 11 is connected to a supply voltage V _CC and simultaneously connected in parallel through a capacitor 16 and thus to ground T _GND . In the present embodiment, the capacitance of the capacitor 16 is 0.1. μF, and the capacitance of the snubber capacitor 13 is 0.1 μF.

As shown in FIG. 6a and FIG. 6b, when a surge such as lightning or static electricity is generated and enters the connector circuit through the signal input terminal 14 along with the connector plug, firstly, the first 12 s through the autotransformer circuit block can be achieved. The effect of the step-down is simultaneously introduced into the ground terminal, and then the surge is again stepped down via the common mode filter coil circuit block 11as, and further passed through the center tap of the isolation transformer circuit block 11s. Partially, the high voltage is again introduced into the grounding terminal, and finally, the effect of slow charging and discharging is achieved by the serial design of the snubber capacitor circuit block 13s of the present invention.

In this way, the maximum value of the surge high voltage is minimized by the above method, thereby ensuring that the network physical layer or the host computer connected to the signal output terminal 15 is not damaged by the surge voltage/current. In order to avoid affecting the signal transmission capability of the connector, the present embodiment uses a 0.1 μF snubber capacitor, thereby maintaining the quality of the signal transmission under the premise of circuit protection.

In addition, the inventor of the present invention further proposes a circuit diagram of another embodiment of a surge protection circuit as shown in FIG. 7. As shown in FIG. 7, in the architecture of this embodiment, the only difference from the original embodiment is that When the auto-transformer 12 and its central tap grounding G design are not included in the circuit architecture, in order to ensure the effect of the surge protection, the inventor performs the grounding G design on the central tap portion of the secondary side of the isolating transformer 11, thereby reducing the cost. The host device can still be protected while simplifying the circuit structure.

Thus, through the above, the components and technical features of a surge protection circuit of the present invention have been clearly and completely described, and the advantages of the design of the present invention will be further described in the following.

Please refer to FIG. 5 and FIG. 7 for further reference, and please refer to FIG. 8 at the same time, which is an exploded view of the actual application of the surge protection circuit of the present invention. As shown in the figure, the design of the snubber capacitor 13 of the present invention can not only replace the conventional use. The anti-surge protector has the disadvantages, and in addition, it has the advantages of lower cost and less required circuit space through the arrangement of the snubber capacitor, so that the circuit is designed on the PCB board S and mounted on the housing. In H, there is a higher and more abundant space utilization degree; in addition, the setting of the snubber capacitor can achieve a higher surge protection effect in a relatively low cost state.

It is to be understood that the foregoing detailed description of the embodiments of the present invention is not intended to limit the scope of the present invention. Both should be included in the scope of the patent in this case.

1'‧‧‧RJ45 electrical connector module
10'‧‧‧RJ45 electrical connector
11'‧‧‧Isolation transformer
Im'‧‧‧matching resistor
C _HV '‧‧‧High Voltage Capacitor
111'‧‧‧Signal input interface
112'‧‧‧Signal receiving interface
AT‧‧‧Autotransformer
T _GND ‧‧‧ Grounding
P‧‧‧Anti-surge protector
S‧‧‧PCB board
G‧‧‧ Grounding
H‧‧‧shell
11‧‧‧Isolation transformer
11a‧‧‧Common mode filter coil
12‧‧‧Autotransformer
13‧‧‧ snubber capacitor
14‧‧‧Signal input terminal
15‧‧‧Signal output terminal
16‧‧‧ Capacitance
12s‧‧‧Autotransformer Circuit Block
11as‧‧‧Common Mode Filter Coil Circuit Block
11s‧‧‧Isolation transformer circuit block
13s‧‧‧ snubber capacitor circuit block
V _CC ‧‧‧Power supply voltage

Figure 1 is a conventional RJ45 electrical connector module; Figure 2 is an equivalent circuit diagram of the isolation transformer inside the conventional RJ45 electrical connector module; Figure 3 is a circuit diagram of the isolation transformer inside another RJ45 electrical connector module Figure 4 is a circuit diagram of an isolation transformer inside another RJ45 electrical connector module; Figure 5 is a circuit diagram of a surge protection circuit of the present invention; Figure 6a to Figure 6b are surge voltage guidance of the surge protection circuit FIG. 7 is a circuit diagram of another embodiment of a surge protection circuit of the present invention; and FIG. 8 is an exploded view of the application of the surge protection circuit.

T _GND ‧‧‧ Grounding

S‧‧‧PCB board

G‧‧‧ Grounding

11‧‧‧Isolation transformer

11a‧‧‧Common mode filter coil

12‧‧‧Autotransformer

13‧‧‧ snubber capacitor

14‧‧‧Signal input terminal

15‧‧‧Signal output terminal

16‧‧‧ Capacitance

V _CC ‧‧‧Power supply voltage

Claims (8)

A surge protection circuit includes at least one filter module, and the filter module includes: an isolation transformer having a primary side and a secondary side, and the primary side is coupled through two signal output terminals And a common mode filter coil, wherein one end is coupled to a signal receiving interface and the other end is coupled to a secondary side of the isolation transformer; and wherein the primary side of the isolation transformer and the signal output terminal A snubber capacitor is connected in series. The surge protection circuit of claim 1, further comprising an auto-transformer, wherein the autotransformer is coupled between the common mode filter coil and the signal receiving interface. The surge protection circuit of claim 2, wherein the center-tapped (CT) of the autotransformer is grounded. The surge protection circuit of claim 1, wherein the common mode filter coil is coupled to the signal receiving interface through two signal input terminals. The surge protection circuit of claim 1, wherein the central tap portion of the primary side of the isolation transformer is coupled to a capacitor and grounded. The surge protection circuit of claim 5, wherein the capacitor has a capacitance of 0.1 μF. The surge protection circuit of claim 1, wherein the central tap portion of the primary side of the isolation transformer is connected to a supply voltage. The surge protection circuit of claim 1, wherein the snubber capacitor has a capacitance of 0.1 μF.