TWI452791B - Power protection circuit - Google Patents

Description

Power failure protection circuit

The invention relates to a power-off protection circuit, in particular to a power-off protection circuit applied to a portable electronic device.

With the improvement of people's living standards and consumption standards, mobile electronic devices such as mobile phone, MP3 (Moving Picture Experts Group Audio Layer III), Personal Digital Assistant (PDA), etc., with voice functions, are competing for consumption. You can fully enjoy the convenience brought by high technology anytime, anywhere. On the other hand, the portable electronic device is likely to enter or get wet due to accidents during use, and may cause a short circuit in part of the motherboard, resulting in more serious damage. Therefore, it is an indispensable measure to prevent the electronic device from being damaged by accidental water ingress or dampness, thereby prolonging the service life of the electronic device.

At present, the general waterproof or moisture-proof method mainly adopts mechanical waterproofing, that is, the outer casing of the electronic device is made of materials that are closely connected to each other to prevent water or moisture from entering. However, if it is used for a long time, most of the outer casings may form gaps due to wear and looseness, which may still cause the portable electronic device to enter the water, causing partial circuit short circuit damage and damage to water vapor. . In addition, the cost of the mechanical waterproofing method is also high, and the manufacturing process is complicated.

In view of this, it is necessary to provide a waterproof and moisture-proof, and can better protect the electronic device. Set the power-off protection circuit.

A power-off protection circuit is installed in an electronic device. The power-off protection circuit includes a protection unit, a humidity detection unit electrically connected to the protection unit, and a processor unit electrically connected to the protection unit and the humidity detection unit. The humidity detecting unit detects whether moisture enters the electronic device, and the processor unit controls the protection unit to be turned on or off according to the detection result of the humidity detecting unit.

Compared with the prior art, when the moisture detecting unit of the power-off protection circuit detects that moisture has entered the electronic device, the processor unit can control the protection unit to automatically cut off to power off the electronic device to protect the device. Electronic device. The power-off protection circuit structure and the manufacturing process are simple, the cost is low, and the demand of the consumer is well satisfied.

100‧‧‧Power-off protection circuit

20‧‧‧Protection unit

32‧‧‧First coil

40‧‧‧ Processor unit

44‧‧‧Power input pin

200‧‧‧Electronic devices

4‧‧‧ keyboard

10‧‧‧Power unit

30‧‧‧Humidity detection unit

34‧‧‧second coil

42‧‧‧Signal input pin

46‧‧‧Signal output pin

2‧‧‧ Shell

1 is a schematic structural view of a power-off protection circuit according to a preferred embodiment of the present invention.

2 is a schematic view showing a mounting position of a humidity detecting unit in a power-off protection circuit according to a preferred embodiment of the present invention.

Referring to FIG. 1 and FIG. 2, the power-off protection circuit 100 of the preferred embodiment of the present invention is applicable to an electronic device 200 such as a mobile phone, an MP3, a PDA, or the like, for protecting the electronic device 200 from damage due to water ingress or moisture. The electronic device 200 includes a casing 2, a keyboard 4 and a plurality of I/O interfaces (not shown). The casing 2 is for protecting internal components of the electronic device 200, and the keyboard 4 is used for inputting information. The I/O interface is used to input and output information.

The power-off protection circuit 100 includes a power supply unit 10, a protection unit 20 electrically connected to the power supply unit 10, and a humidity check electrically connected to the protection unit 20. The measuring unit 30 and a processor unit 40 electrically connected to the protection unit 20 and the humidity detecting unit 30.

The power unit 10 is a power source (such as a lithium battery or the like) in the electronic device 200, and is used to provide a stable working power support for the electronic device 200.

The protection unit 20 is a power-off protection device (such as a fuse, etc.), and the different levels received by the protection unit 20 may cause a change in the current therein, and the protection unit 20 may be turned on or off under the action of the change current.

The humidity detecting unit 30 includes a first coil 32 and a second coil 34. When moisture enters between the first coil 32 and the second coil 34, a channel is formed between the two due to the conduction of water. . Referring to FIG. 2 , it can be understood that, in order to ensure that the moisture detecting unit 30 can detect the incoming moisture from different positions of the electronic device 200 in time, a plurality of humidity detecting units 30 can be disposed at the boundary of the outer casing 2 of the electronic device 200 . And other locations that are easy to enter (for example, the junction of the outer casing 2, the keyboard 4, the I/O interface, etc.). Obviously, some of the first coils 32 of the plurality of humidity detecting units 30 can be connected to one wire, and the second coils 34 are connected to the other wire.

The processor unit 40 includes a signal input pin 42 electrically connected to the second coil 34, an input power, and is electrically connected to the first coil 32 and the protection unit 20. A power input pin (Power) 44 and a signal output pin (46) electrically connected to the protection unit 20. The signal output pin 46 is controlled by the signal input pin 42 and the levels of the two are consistent. The signal output pin 46 controls the protection unit 20 to be turned on or off. When the signal output pin 46 is at a low level, the protection unit 20 is turned on, and the power supply unit 10 operates normally; when the signal output pin 46 is at a high level, the protection is performed. The unit 20 is turned off, and the power supply unit 10 cannot supply power. Normally (there is no moisture entering between the first coil 32 and the second coil 34) The signal input pin 42 and the signal output pin 46 are both low.

The working principle of the power-off protection circuit 100 is as follows: when the electronic device 200 is in a humid environment or falls into water, moisture may enter between the first coil 32 and the second coil 34. A path is formed between the first coil 32 and the second coil 34, and a path is also formed between the signal input pin 42 and the power input pin 44, and the signal input pin 42 changes from a low level to a high level. . The signal output pin 46 is controlled by the signal input pin 42 to change from a low level to a high level, and the protection unit 20 is switched from an on state to an off state by the control of the signal output pin 46. At this time, the power supply unit 10 stops supplying power to the electronic device 200, and functions to protect the internal circuit of the electronic device 200, thereby achieving the purpose of protecting the entire electronic device 200.

It can be understood that the protection unit 20 can be designed as a detachable device. When the water on the electronic device 200 is cleaned, the protection unit 20 can be loaded to detect whether the power supply of the electronic device 200 is normal.

It can be understood that the first coil 32 can be electrically connected to the power input pin 44 or can be electrically connected to the signal input pin 42. The second coil 34 can be input with the signal. The pin 42 is electrically connected to the power input pin 44.

The structure and manufacturing process of the power-off protection circuit 100 are simple. When the electronic device 200 is in a humid environment or falls into water, the system automatically powers off, which can prevent the circuit of the electronic device 200 from being damaged, and better protects the entire electronic device. The purpose of the device 200.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above embodiments, and those skilled in the art can make the spirit of the present invention. Equivalent modifications or variations are intended to be included within the scope of the following claims.

100‧‧‧Power-off protection circuit

20‧‧‧Protection unit

32‧‧‧First coil

40‧‧‧ Processor unit

44‧‧‧Power input pin

10‧‧‧Power unit

30‧‧‧Humidity detection unit

34‧‧‧second coil

42‧‧‧Signal input pin

46‧‧‧Signal output pin

Claims (7)

A power-off protection circuit is installed in an electronic device, and the improvement is that the power-off protection circuit includes a protection unit, a humidity detecting unit electrically connected to the protection unit, and a protection unit a processor unit electrically connected to the humidity detecting unit, the processor unit includes a signal input pin electrically connected to the humidity detecting unit, and a signal output pin electrically connected to the protection unit, The humidity detecting unit detects whether moisture enters the electronic device, and the processor unit inputs a signal through the signal input pin to confirm the detection result of the humidity detecting unit, and controls the protection unit to be turned on or off by the signal output pin. The power-off protection circuit of claim 1, wherein the power-off protection circuit comprises a power supply unit electrically connected to the protection unit, and the power supply unit is configured to provide the power-off protection circuit Working power. The power-off protection circuit of claim 1, wherein the processor unit includes a power input pin electrically connected to the protection unit and the humidity detection unit, and the power input pin is used for A power source is provided to provide power to the processor unit. The power-off protection circuit of claim 1, wherein the signal input pin further controls a signal output by the signal output pin, and the levels of the two are consistent. The power-off protection circuit of claim 4, wherein the humidity detecting unit comprises a first coil and a second coil, and when moisture enters the humidity detecting unit, the first coil and the first coil A path is formed between the two coils, the signal input pin activates the signal output pin, and controls the protection unit to be turned off to stop supplying power to the electronic device. The power-off protection circuit of claim 4, wherein an open circuit is formed between the first coil and the second coil when no moisture enters the humidity detecting unit, the protection unit Maintaining a normal working state to continue to supply power to the electronic device. The power-off protection circuit of claim 1, wherein the humidity detecting unit is disposed at a housing joint of the electronic device, a keyboard, and an I/O interface.