Secondary overcurrent protection system

Abstract

The utility model relates to a secondary overcurrent protection system. The secondary overcurrent protection system comprises a power supply chip module; and the element protection module comprises a voltage output point, a first protection unit and a second protection unit, the voltage output point is electrically connected with the power supply chip module, the first protection unit is electrically connected with the voltage output point, and the second protection unit is electrically connected with the first protection unit. According to the scheme provided by the invention, the power supply of the television mainboard can be cut off when the circuit of the television mainboard fails, so that the voltage output point keeps low-level output, and components of the television mainboard are prevented from being damaged.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit design, in particular to a secondary overcurrent protection system. Background Art

[0002] The switching power supply currently used in LCD TVs will supply normal operating current to the TV motherboard when the TV is working normally. However, when the TV motherboard circuit fails, the power current supplied to the TV motherboard will increase rapidly, thereby damaging the motherboard components. Utility Model Content

[0003] The purpose of the utility model is to overcome the deficiencies in the prior art and provide a secondary overcurrent protection system which can cut off the power supply of the TV mainboard when a fault occurs in the TV mainboard circuit to avoid damage to the components of the TV mainboard.

[0004] The purpose of this utility model is achieved through the following technical solutions:

[0005] The first aspect of the present application provides a secondary overcurrent protection system, comprising: a power chip module; a component protection module, the component protection module comprising a voltage output point, a first protection unit and a second protection unit, the voltage output point is electrically connected to the power chip module, the first protection unit is electrically connected to the voltage output point, and the second protection unit is electrically connected to the first protection unit.

[0006] The second protection unit includes a jumper JP16 and a protection chip U105 . A first end of the jumper JP16 is used to be electrically connected to an external power source, and a second end of the jumper JP16 is electrically connected to the protection chip U105 .

[0007] The first protection unit includes a resistor R304, a capacitor C303 and a resistor R308, a first end of the resistor R304 is electrically connected to the protection chip U105, a second end of the resistor R304 is electrically connected to a first end of the capacitor C303, a second end of the capacitor C303 is grounded, a first end of the resistor R308 is electrically connected to a second end of the resistor R304, and a second end of the resistor R308 is electrically connected to a second end of the capacitor C303.

[0008] The first protection unit further includes a transistor Q104 , and the transistor Q104 is electrically connected to a first end of the resistor R308 .

[0009] The first protection unit further includes a transistor Q109 electrically connected to a first end of the capacitor C303.

[0010] The first protection unit also includes a resistor R309, a capacitor C307 and a jumper J17, the first end of the resistor R309 is electrically connected to the transistor Q109, the second end of the resistor R309 is electrically connected to the first end of the jumper J17, the first end of the capacitor C307 is electrically connected to the first end of the resistor R309, the second end of the capacitor C307 is electrically connected to the first end of the jumper J17, and the second end of the jumper J17 is electrically connected to the voltage output point.

[0011] The second protection unit further includes a resistor R301 and a resistor R302, wherein the first end of the resistor R301 is electrically connected to an external power supply, the second end of the resistor R301 is electrically connected to the protection chip U105, and the first end of the resistor R302 is electrically connected to the second end of R301.

[0012] The second protection unit further includes a resistor R310 and a resistor R303, wherein a first end of the resistor R310 is electrically connected to a second end of the resistor R302, a first end of the resistor R303 is electrically connected to a second end of the resistor R302, and a second end of the resistor R310 is electrically connected to a second end of the resistor R303.

[0013] The second protection unit further includes a capacitor C305 and a resistor R307, wherein a first end of the capacitor C305 is electrically connected to the protection chip U105, a second end of the capacitor C305 is electrically connected to a first end of the resistor R307, and a second end of the resistor R307 is electrically connected to the protection chip U105.

[0014] The second protection unit also includes a jumper J18, a resistor R306 and an output point, the first end of the jumper J18 is electrically connected to the protection chip U105, the second end of the jumper J18 is electrically connected to the first end of the resistor R306, the second end of the resistor R306 is electrically connected to the output point, and the output point is electrically connected to the power chip module.

[0015] Compared with the prior art, the utility model has at least the following advantages:

[0016] By setting a component protection module in the power chip module, the power supply of the TV mainboard can be cut off when a fault occurs in the TV mainboard circuit, so that the voltage output point maintains a low level output, thereby avoiding damage to the components of the TV mainboard. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for use in the embodiments are briefly introduced below.

[0018] Figure 1This is a functional module diagram of a secondary overcurrent protection system in an embodiment of the present utility model;

[0019] Figure 2 4 is a circuit diagram of a secondary overcurrent protection system in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0021] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] Unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, or a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0023] The switching power supply currently used in LCD TVs will supply normal operating current to the TV motherboard when the TV is working normally. However, when the TV motherboard circuit fails, the power current supplied to the TV motherboard will increase rapidly, thereby damaging the motherboard components.

[0024] In response to the above problems, an embodiment of the present application provides a secondary overcurrent protection system, which can cut off the power supply of the TV mainboard when a fault occurs in the TV mainboard circuit, thereby avoiding damage to components of the TV mainboard.

[0025] The technical solution of the embodiments of the present application is described in detail below with reference to the accompanying drawings.

[0026] See also Figure 1A secondary overcurrent protection system includes: a power chip module 100; a component protection module 200, the component protection module 200 includes a voltage output point 210, a first protection unit 220 and a second protection unit 230, the voltage output point 210 is electrically connected to the power chip module 100, the first protection unit 220 is electrically connected to the voltage output point 210, and the second protection unit 230 is electrically connected to the first protection unit 220.

[0027] It should be noted that the power chip module 100 is a power chip integrated circuit. By adding a component protection module 200 to the power chip integrated circuit, when a fault occurs in the TV mainboard circuit, the power supply of the TV mainboard can be cut off to avoid damage to the components of the TV mainboard.

[0028] See also Figure 2 Specifically, the second protection unit 230 includes a jumper JP16 and a protection chip U105, a first end of the jumper JP16 is used to be electrically connected to an external power supply, and a second end of the jumper JP16 is electrically connected to the protection chip U105.

[0029] See also Figure 2 Specifically, the first protection unit 220 includes a resistor R304, a capacitor C303 and a resistor R308, a first end of the resistor R304 is electrically connected to the protection chip U105, a second end of the resistor R304 is electrically connected to a first end of the capacitor C303, a second end of the capacitor C303 is grounded, a first end of the resistor R308 is electrically connected to a second end of the resistor R304, and a second end of the resistor R308 is electrically connected to a second end of the capacitor C303.

[0030] It should be noted that the resistor R304 and the resistor R308 are voltage-dividing resistors, and the capacitor C303 is a filter capacitor.

[0031] See also Figure 2 Specifically, the first protection unit 220 further includes a transistor Q104, which is electrically connected to a first end of the resistor R308, and the first protection unit 220 further includes a transistor Q109 which is electrically connected to a first end of the capacitor C303.

[0032] It should be noted that transistor Q104 is an NPN transistor, and transistor Q109 is a PNP transistor. When the current rises to the set value, the voltage at the voltage output point OCP rises to the VCC2 voltage. After the voltage is divided by resistors R304 and R308 and filtered by capacitor C303, the base of transistor Q104 is at a high level, the collector of transistor Q104 is connected to the ground, the base-collector voltage of transistor Q109 is pulled to the ground, the collector of transistor Q109 and the base of the NPN transistor are connected, and the voltage output point OCP is kept at a low level, so that no signal passes through the feedback optocoupler of the power chip module, and the power chip enters the protection state.

[0033] See also Figure 2 In one embodiment, the first protection unit 220 further includes a resistor R309, a capacitor C307 and a jumper J17, the first end of the resistor R309 is electrically connected to the transistor Q109, the second end of the resistor R309 is electrically connected to the first end of the jumper J17, the first end of the capacitor C307 is electrically connected to the first end of the resistor R309, the second end of the capacitor C307 is electrically connected to the first end of the jumper J17, and the second end of the jumper J17 is electrically connected to the voltage output point.

[0034] It should be noted that the resistor R309 and the capacitor C307 play an anti-interference role.

[0035] See also Figure 2 In one embodiment, the second protection unit 230 further includes a resistor R301 and a resistor R302, wherein the first end of the resistor R301 is electrically connected to an external power supply, the second end of the resistor R301 is electrically connected to the protection chip U105, and the first end of the resistor R302 is electrically connected to the second end of R301.

[0036] Specifically, the second protection unit 230 also includes a resistor R310 and a resistor R303, wherein the first end of the resistor R310 is electrically connected to the second end of the resistor R302, the first end of the resistor R303 is electrically connected to the second end of the resistor R302, and the second end of the resistor R310 is electrically connected to the second end of the resistor R303.

[0037] It should be noted that the resistor R301 , the resistor R302 , the resistor R310 , and the resistor R303 are voltage-stabilizing resistors.

[0038] See also Figure 2 In one embodiment, the second protection unit 230 further includes a capacitor C305 and a resistor R307, a first end of the capacitor C305 is electrically connected to the protection chip U105, a second end of the capacitor C305 is electrically connected to the first end of the resistor R307, and a second end of the resistor R307 is electrically connected to the protection chip U105.

[0039] It should be noted that the capacitor C305 is a filter capacitor and the resistor R307 plays a role of current limiting.

[0040] See also Figure 2 In one embodiment, the second protection unit 230 also includes a jumper J18, a resistor R306 and an output point, the first end of the jumper J18 is electrically connected to the protection chip U105, the second end of the jumper J18 is electrically connected to the first end of the resistor R306, the second end of the resistor R306 is electrically connected to the output point, and the output point is electrically connected to the power chip module.

[0041] It should be noted that the resistor R306 has the function of current limiting and circuit protection.

[0042] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the descriptions of the various embodiments have their own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the specification are not necessarily required for the present application. In addition, it can be understood that the steps in the method of the embodiment of the present application can be adjusted in order, merged and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be merged, divided and deleted according to actual needs.

[0043] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A secondary overcurrent protection system, characterized in that: include: Power chip module; The component protection module includes a voltage output point, a first protection unit and a second protection unit, the voltage output point is electrically connected to the power chip module, the first protection unit is electrically connected to the voltage output point, and the second protection unit is electrically connected to the first protection unit.

2. The secondary overcurrent protection system according to claim 1, characterized in that: The second protection unit includes a jumper JP16 and a protection chip U105 . A first end of the jumper JP16 is used to be electrically connected to an external power source, and a second end of the jumper JP16 is electrically connected to the protection chip U105 .

3. The secondary overcurrent protection system according to claim 2, characterized in that: The first protection unit includes a resistor R304, a capacitor C303 and a resistor R308, a first end of the resistor R304 is electrically connected to the protection chip U105, a second end of the resistor R304 is electrically connected to a first end of the capacitor C303, a second end of the capacitor C303 is grounded, a first end of the resistor R308 is electrically connected to a second end of the resistor R304, and a second end of the resistor R308 is electrically connected to a second end of the capacitor C303.

4. The secondary overcurrent protection system according to claim 3, characterized in that: The first protection unit further includes a transistor Q104 , and the transistor Q104 is electrically connected to a first end of the resistor R308 .

5. The secondary overcurrent protection system according to claim 3, characterized in that: The first protection unit further includes a transistor Q109 electrically connected to a first end of the capacitor C303.

6. The secondary overcurrent protection system according to claim 5, characterized in that: The first protection unit also includes a resistor R309, a capacitor C307 and a jumper J17, the first end of the resistor R309 is electrically connected to the transistor Q109, the second end of the resistor R309 is electrically connected to the first end of the jumper J17, the first end of the capacitor C307 is electrically connected to the first end of the resistor R309, the second end of the capacitor C307 is electrically connected to the first end of the jumper J17, and the second end of the jumper J17 is electrically connected to the voltage output point.

7. The secondary overcurrent protection system according to claim 5, characterized in that: The second protection unit further includes a resistor R301 and a resistor R302, wherein the first end of the resistor R301 is electrically connected to an external power supply, the second end of the resistor R301 is electrically connected to the protection chip U105, and the first end of the resistor R302 is electrically connected to the second end of R301.

8. The secondary overcurrent protection system according to claim 7, characterized in that: The second protection unit further includes a resistor R310 and a resistor R303, wherein a first end of the resistor R310 is electrically connected to a second end of the resistor R302, a first end of the resistor R303 is electrically connected to a second end of the resistor R302, and a second end of the resistor R310 is electrically connected to a second end of the resistor R303.

9. The secondary overcurrent protection system according to claim 7, characterized in that: The second protection unit further includes a capacitor C305 and a resistor R307, wherein a first end of the capacitor C305 is electrically connected to the protection chip U105, a second end of the capacitor C305 is electrically connected to a first end of the resistor R307, and a second end of the resistor R307 is electrically connected to the protection chip U105.

10. The secondary overcurrent protection system according to claim 9, characterized in that: The second protection unit also includes a jumper J18, a resistor R306 and an output point, the first end of the jumper J18 is electrically connected to the protection chip U105, the second end of the jumper J18 is electrically connected to the first end of the resistor R306, the second end of the resistor R306 is electrically connected to the output point, and the output point is electrically connected to the power chip module.

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