CN110896213A

CN110896213A - Power protection circuit and network camera

Info

Publication number: CN110896213A
Application number: CN201911270457.3A
Authority: CN
Inventors: 唐磊
Original assignee: Shenzhen Baichuan Security Technology Co Ltd
Current assignee: Shenzhen Baichuan Security Technology Co Ltd
Priority date: 2019-12-12
Filing date: 2019-12-12
Publication date: 2020-03-20

Abstract

The invention provides a power supply protection circuit and a network camera, wherein the power supply protection circuit is arranged between a power supply input port and an equipment mainboard, and comprises the following components: the device comprises a power supply input port, a first protection circuit module, a second protection circuit module and an equipment mainboard, wherein the power supply input port, the first protection circuit module, the second protection circuit module and the equipment mainboard are sequentially connected, the first protection circuit module comprises at least one TVS diode, the first end of the TVS diode is connected with the power supply input port and the second protection circuit module, and the second end of the TVS diode is grounded; the camera comprises the power supply protection circuit.

Description

Power protection circuit and network camera

Technical Field

The invention relates to the field of network cameras, in particular to a power supply protection circuit and a network camera.

Background

In the IPC (IP CAMERA, internet protocol CAMERA) field, more and more users choose to install video monitoring equipment outdoors due to the maturity of technologies such as solar power supply and wireless transmission. When a user takes off the IPC equipment for charging, the user occasionally uses an adapter with poor quality or wrong model, furthermore, the IPC equipment is struck by lightning at a certain probability when being installed at a higher position outdoors, and the equipment can be damaged due to the fact that the IPC equipment bears overhigh voltage under the scenes. This presents challenges to power protection of IPC devices.

Disclosure of Invention

In order to solve the above problems, the present invention provides a power protection circuit, which effectively avoids the damage of the IPC device due to the over-high input voltage.

The invention provides a power protection circuit, which is arranged between a power input port and an equipment mainboard and comprises: first protection circuit module and second protection circuit module, the power input port, first protection circuit module, second protection circuit module and the equipment mainboard connects gradually, wherein, first protection circuit module includes at least one TVS diode, the first end of TVS diode with the power input port and the second protection circuit module is connected, the second end ground connection of TVS diode.

The invention also provides a network camera, and the network camera is provided with the power supply protection circuit.

The power supply protection circuit is arranged between the power supply input port and the equipment mainboard, so that the damage of the IPC equipment caused by overvoltage can be effectively reduced, and the damage of the IPC equipment caused by lightning stroke because the IPC equipment is arranged at a higher position in the outdoor use process is particularly avoided.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, some brief descriptions will be given below to the drawings required to be used in the description of the embodiments or the prior art, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic diagram of a first power protection circuit according to an embodiment of the invention;

fig. 2 is a schematic diagram of a second power protection circuit according to an embodiment of the invention;

fig. 3 is a schematic diagram of a third power protection circuit according to an embodiment of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

As shown in fig. 1, the power protection circuit provided in an embodiment of the present invention is disposed between a power input port and an equipment motherboard, and includes: the protection circuit module comprises a first protection circuit module M1 and a second protection circuit module M2, a power supply input port (not shown in FIG. 1), a first protection circuit module M1, a second protection circuit module M2 and the equipment main board (not shown in FIG. 1) are connected in sequence, wherein the first protection circuit module comprises at least one TVS diode D1, a first end of the TVS diode D1 is connected with the power supply input port and the second protection circuit module M2, and a second end of the TVS diode D1 is grounded.

According to the power supply protection circuit provided by the embodiment of the invention, the two-stage overvoltage protection circuit is arranged between the power supply input port and the equipment mainboard, wherein the TVS tube in the first protection circuit module can bear larger discharge current and is mainly used for absorbing and sensing surge voltage when the IPC equipment is struck by lightning and clamping the input voltage in a lower range; if the voltage clamped by the TVS tube is still higher than the acceptable input voltage specification of the equipment, the second circuit protection module is used for further protection.

Optionally, in the power protection circuit according to the embodiment of the present invention, as shown in fig. 2, the second protection circuit module M2 includes: the circuit comprises a first MOS transistor Q1, a second MOS transistor Q2, at least one triode Q3, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4 and a fifth resistor R5; the D pole of the first MOS transistor Q1 is connected to the first protection circuit module M1, the S pole is connected to an equipment main board (not shown in fig. 2), and the G pole is connected to the first end of the second resistor R2; a D pole of the second MOS transistor Q2 is connected to the first protection circuit module M1, an S pole is connected to a first end of the second resistor R2, and a G pole is connected to a first end of the fourth resistor R4; a first end of the first resistor R1 is connected with the first protection circuit module M1, and a second end is connected with a first end of the fifth resistor R5; a first end of the second resistor R2 is connected with the G pole of the first MOS transistor Q1, and a second end is grounded; a first end of the third resistor R3 is connected with the first protection circuit module M1, and a second end is connected with a second end of the fourth resistor R4; a first end of the fourth resistor R4 is connected with the G pole of the second MOS transistor Q2, and a second end is connected with a second end of the third resistor R3; a first end of the fifth resistor R5 is connected with a second end of the first resistor R1, and the second end is grounded; the base of the transistor Q3 is connected between the first resistor R1 and the fifth resistor R5, the collector is connected between the third resistor R3 and the fourth resistor R4, and the emitter is grounded.

In the power protection circuit provided by the embodiment of the invention, when the voltage clamped by the TVS in the first protection circuit module is still higher than the acceptable input voltage specification of the device, the second protection circuit module performs secondary protection, wherein the first resistor and the fifth resistor are used for voltage division, an overvoltage threshold is set, when the input voltage exceeds the threshold, the first resistor and the fifth resistor divide the voltage to drive the transistor Q3 to be conducted, the G pole of the second MOS transistor is pulled down through the fourth resistor to realize the conduction of the second MOS transistor, and at this time, the G pole of the first MOS transistor is the same as the S pole voltage, so that the disconnection of the first MOS transistor is realized, and the power supply to the device is stopped. When the input voltage is lower than the threshold voltage, the first resistor and the fifth resistor are divided too low, the triode is in a cut-off state in work, the second MOS tube is disconnected, and the first MOS tube pulls down the S pole under the action of the second resistor, so that the first MOS tube is switched on to supply power for equipment.

Optionally, in the power protection circuit provided in the embodiment of the present invention, the resistances of the first resistor, the second resistor, the third resistor, and the fourth resistor are 10K Ω, and the resistance of the fifth resistor is 1K Ω.

Optionally, in the power protection circuit provided in the embodiment of the present invention, the first MOS transistor and the second MOS transistor are CES2307 transistors, and the triode is 3904 transistor.

Optionally, as shown in fig. 3, the power protection circuit according to the embodiment of the present invention further includes at least one capacitor C1, a first end of the capacitor C1 is connected between the first protection circuit module and the second protection circuit module, and a second end of the capacitor C1 is grounded.

The grounding capacitor is arranged between the first protection circuit module and the second protection circuit module and is mainly used for absorbing the overshoot voltage of the equipment at the moment of inserting the charging adapter.

Optionally, in the power protection circuit provided in the embodiment of the present invention, a capacitance value of the capacitor is 1 uF.

The network camera provided by the embodiment of the invention comprises the power supply protection circuit in any one of the preceding embodiments.

By adding the power supply protection circuit provided by the embodiment of the invention into the IPC equipment, the damage of the equipment caused by overhigh input voltage, such as lightning stroke suffered by monitoring equipment because the monitoring equipment is installed higher outdoors and overshoot voltage caused by mistaken use of a charging adapter by a user, can be effectively avoided. The power supply protection circuit provided by the invention has the advantages of simple and efficient circuit design and low cost.

Although a variety of terms for circuits, modules, pipes, etc. are used more often herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The utility model provides a power supply protection circuit, its characterized in that, power supply protection circuit sets up between power input port and equipment mainboard, includes: first protection circuit module and second protection circuit module, the power input port, first protection circuit module, second protection circuit module and the equipment mainboard connects gradually, wherein, first protection circuit module includes at least one TVS diode, the first end of TVS diode with the power input port and the second protection circuit module is connected, the second end ground connection of TVS diode.

2. The power protection circuit of claim 1, wherein the second protection circuit module comprises: the circuit comprises a first MOS tube, a second MOS tube, at least one triode, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; the D pole of the first MOS tube is connected with the first protection circuit module, the S pole of the first MOS tube is connected with the equipment mainboard, and the G pole of the first MOS tube is connected with the first end of the second resistor; the D pole of the second MOS tube is connected with the first protection circuit module, the S pole of the second MOS tube is connected with the first end of the second resistor, and the G pole of the second MOS tube is connected with the first end of the fourth resistor; the first end of the first resistor is connected with the first protection circuit module, and the second end of the first resistor is connected with the first end of the fifth resistor; the first end of the second resistor is connected with the G pole of the first MOS tube, and the second end of the second resistor is grounded; the first end of the third resistor is connected with the first protection circuit module, and the second end of the third resistor is connected with the second end of the fourth resistor; the first end of the fourth resistor is connected with the G pole of the second MOS transistor, and the second end of the fourth resistor is connected with the second end of the third resistor; the first end of the fifth resistor is connected with the second end of the first resistor, and the second end of the fifth resistor is grounded; the base electrode of the triode is connected between the first resistor and the fifth resistor, the collector electrode of the triode is connected between the third resistor and the fourth resistor, and the emitting electrode of the triode is grounded.

3. The power protection circuit of claim 2, wherein the first resistor, the second resistor, the third resistor and the fourth resistor have a resistance of 10K Ω, and the fifth resistor has a resistance of 1K Ω.

4. The power protection circuit of claim 2, wherein the first MOS transistor and the second MOS transistor are CES2307 transistors, and the triode is 3904 transistor.

5. The power protection circuit of claim 1, further comprising at least one capacitor having a first terminal connected between the first protection circuit module and the second protection circuit module and a second terminal connected to ground.

6. The power protection circuit according to claim 4, wherein the capacitance of the capacitor is 1 uF.

7. A network camera characterized in that it comprises a power supply protection circuit according to any one of claims 1 to 6.