Defense area output protection circuit

Abstract

The utility model discloses a defense area output protection circuit, and relates to the technical field of defense area interfaces. The defence area output protection circuit is used for a power supply output interface of a defence area interface and comprises a diode D1, the positive electrode of the diode D1 is connected with VCC, the negative electrode of the diode D1 is connected with a second pin of the power supply output interface through a fuse F1, and the second pin is a power supply output pin; the negative electrode of the diode D2 is connected with the negative electrode of the diode D1, and the positive electrode is connected with the first pin of the power supply output interface; and the first pin is connected with the GND. The defence area output protection circuit provided by the utility model is small in hardware space occupation and low in cost, not only can prevent a defence area interface from accessing a large load to influence the stability of equipment, but also can reduce the maintenance and repair cost caused by wrong wiring.

Description

TECHNICAL FIELD

[0001] The utility model relates to a guard area interface technical field, concretely relates to a guard area output protection circuit. BACKGROUND

[0002] Most of the current indoor unit equipment guard area interface designs have power supply output interfaces, which are used to power the user's home sensors and alarm devices.

[0003] However, in use, this power supply output port is easily mistaken as an input port to connect the power supply to the equipment, and even when mistaken as an input port, the positive and negative power supply connections are reversed, causing the board to burn. Secondly, when the client uses this output port to connect a load that exceeds the design specified power requirement, it may affect the normal operation of the equipment. SUMMARY

[0004] The technical problem to be solved by the utility model is to provide a guard area output protection circuit to prevent the influence of a large load connected to the guard area interface on the stability of the equipment and to reduce the cost of maintenance and repair caused by incorrect wiring.

[0005] The utility model is implemented as follows:

[0006] A guard area output protection circuit for the power supply output interface of a guard area interface, comprising:

[0007] A diode D1, the anode is connected to VCC, and the cathode is connected to the second pin of the power supply output interface through a fuse F1, wherein the second pin is a power supply output pin;

[0008] A diode D2, the cathode is connected to the cathode of the diode D1, and the anode is connected to the first pin of the power supply output interface; the first pin is connected to GND.

[0009] Further, the fuse current of the fuse F1 is less than the maximum output current of the equipment end allocated to the power supply output interface branch.

[0010] Further, the rated voltage of the fuse F1 is greater than the VCC voltage.

[0011] Further, the reverse voltage of the diode D1 is greater than the VCC voltage.

[0012] Further, the rated current of the diode D1 is greater than the fuse current of the fuse F1.

[0013] Further, the reverse voltage of the diode D2 is greater than the VCC voltage.

[0014] Further, the rated current of the diode D2 is greater than the fuse current of the fuse F1.

[0015] Further, the fuse F1 adopts a fast-fuse, self-recovery fuse

[0016] The utility model discloses a virtue lies in: the power line of the output of the guard area is added diode D1, avoids the user and uses power output interface as power input, prevents the positive and negative of power supply from being connected reversely and burns the mainboard, and the diode D2 is connected between the positive and negative as the short circuit loop after being connected reversely, and the fuse F1 is additionally increased to realize protection to prevent the power supply from being jerked after the diode D2 is short-circuited, and the user connects the superpower load, thereby guaranteeing the normal work of equipment. This scheme is small in hardware space occupation and low in cost, and can be self-recovered after removing the fault, not only can prevent the stability of equipment from being influenced by the large load connected to the guard area interface, but also can reduce the cost of maintenance and repair caused by wrong connection. BRIEF DESCRIPTION OF DRAWINGS

[0017] The utility model will be further described below in combination with the embodiment and the specific embodiment.

[0018] Figure 1 It is a structure schematic diagram of the guard area output protection circuit of the utility model embodiment. CONCRETE IMPLEMENTING METHOD

[0019] The technical scheme of the utility model will be described clearly and completely below in combination with the drawings and the specific embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the range protected by the utility model.

[0020] In the description of the utility model, it is necessary to explain that, unless another explicit provision and limitation, the terms "mounting", "connection" should be understood in a broad sense, for example, can be fixed connection, can be detachable connection, or integrally connected, can be mechanical connection, can be electrical connection, can be directly connected, can be indirectly connected through the intermediate medium, can be the communication inside two elements. For the person skilled in the art, the specific meaning of the above-mentioned terms in the application can be understood according to the specific circumstances.

[0021] Please refer to Figure 1 The embodiment provides a guard area output protection circuit, which is used for the power supply output interface J1 of the guard area interface, and comprises:

[0022] Diode D1, the positive pole is connected with VCC, the negative pole is connected with the second pin Pin2 of the power supply output interface J1 through the fuse F1, and the second pin is a power supply output pin;

[0023] Diode D2, the negative pole is connected with the negative pole of diode D1, and the positive pole is connected with the first pin Pin1 of the power supply output interface J1, and the first pin Pin1 is connected with GND.

[0024] The power supply output interface J1 is connected to the first pin Pin1 and the second pin Pin2 to supply power to other devices such as sensors, alarm devices, etc.

[0025] The working principle of the protection circuit is as follows:

[0026] 1. When the power supply output interface J1 is connected as input, Pin1 is connected to the negative terminal of the power supply, and Pin2 is connected to the positive terminal of the power supply. Due to the unidirectional conduction of diode D1, the device will not be started.

[0027] 2. When the power supply output interface J1 is connected as input, Pin1 is connected to the positive terminal of the power supply, and Pin2 is connected to the negative terminal of the power supply. Due to the existence of diode D2 and fuse F1, the power input is short-circuited, preventing the IC connected between VCC and GND from being burned by the reverse voltage caused by reverse connection; at the same time, the fuse F1 is blown, preventing the power supply short circuit from causing the device to be damaged by overcurrent.

[0028] 3. When the power supply output interface J1 is normally connected to the load, and the load power is greater than the rated output power, due to the existence of the fuse F1, when the current exceeds the rated value, the fuse is blown, preventing the device from working abnormally due to the low power supply at the device end caused by the large load output.

[0029] 4. The fuse F1 is selected to be fast-blowing and self-recovery, and Itrip needs to be less than the maximum output current of the device end allocated to this shunt, to ensure that it is blown when a super-power load is connected, protecting the device end from being affected, and the rated voltage Vdc needs to be greater than VCC.

[0030] 5. The reverse voltage Vr of diode D1 needs to be greater than VCC to prevent reverse breakdown of the diode when the output of the protection zone is connected as input; at the same time, Io of diode D1 needs to be greater than Itrip of the fuse to prevent the diode from being burned out before the fuse is blown when J1 is connected to a super-rated power load.

[0031] 6. The reverse voltage Vr of diode D2 needs to be greater than VCC to prevent reverse breakdown of the diode when the output of the protection zone is connected as input;

[0032] At the same time, Io of diode D2 needs to be greater than Itrip of the fuse to prevent the diode from being burned out before the fuse is blown when the power supply output interface J1 is connected as input and Pin1 is connected to the positive terminal of the power supply and Pin2 is connected to the negative terminal of the power supply.

[0033] 7. VCC is used to normally supply power to the device, and the output of the protection zone is a parallel power supply branch.

[0034] 8. The parameters of diodes D1, D2 and fuse F1 can also be adjusted according to the requirements to match the protection applications under different conditions.

[0035] The utility model discloses a diode D1 is added on the power line of the output of the guard area, avoids the user to use the power output interface as power input, prevents the positive and negative of power from being connected reversely and burns the mainboard, and the diode D2 is connected reversely as the short circuit loop between the positive and negative, and the fuse F1 is additionally increased to realize the protection to prevent the power from being hit and the user from connecting the superpower load, thereby guaranteeing the normal work of equipment. The scheme has the advantages of small hardware space occupation, low cost, self-recovery after fault removal, prevention of the influence of the connection of large load on the stability of equipment, and reduction of the cost of maintenance and repair caused by wrong connection.

[0036] Although the specific embodiments of the utility model are described above, those skilled in the art should understand that the specific examples described by us are only illustrative, not for limiting the scope of the utility model, and equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the utility model should be covered within the scope of protection of the claims of the utility model.

Claims

1. A zone output protection circuit, characterized in that, The power supply output interface for the security zone interface comprises: a diode D1, the positive electrode of which is connected with VCC, and the negative electrode of which is connected with the second pin of the power supply output interface through a fuse F1, the second pin being a power supply output pin; a diode D2, the negative electrode of which is connected with the negative electrode of the diode D1, and the positive electrode of which is connected with the first pin of the power supply output interface, the first pin being connected with GND.

2. The perimeter output protection circuit of claim 1, wherein: The fusing current of the fuse F1 is less than the maximum output current of the equipment end distribution to the power supply output interface branch rating.

3. The perimeter output protection circuit according to claim 1 or 2, characterized in that: The rated voltage of the fuse F1 is greater than the VCC voltage.

4. The perimeter output protection circuit of claim 1, wherein: The reverse voltage of the diode D1 is greater than the VCC voltage.

5. The perimeter output protection circuit according to claim 1 or 4, characterized in that: The rated current of the diode D1 is greater than the fusing current of the fuse F1.

6. The perimeter output guard circuit of claim 1, wherein: The reverse voltage of the diode D2 is greater than the VCC voltage.

7. The perimeter output protection circuit according to claim 1 or 6, characterized in that: The rated current of the diode D2 is greater than the fusing current of the fuse F1.

8. The perimeter output protection circuit of claim 1, wherein: The fuse F1 is a fast-fusing and self-recovery fuse.

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