CN111211608A

CN111211608A - Charging short-circuit protection circuit and method and power adapter

Info

Publication number: CN111211608A
Application number: CN202010020823.6A
Authority: CN
Inventors: 余建明
Original assignee: Guangdong Genius Technology Co Ltd
Current assignee: Guangdong Genius Technology Co Ltd
Priority date: 2020-01-09
Filing date: 2020-01-09
Publication date: 2020-05-29
Also published as: CN113113959A; CN113113960A; CN113113957A; CN111835074A; CN113113958B; CN111817414A; CN113113958A

Abstract

The invention provides a charging short-circuit protection circuit, a method and a power adapter, wherein the circuit comprises: the power supply unit is used for accessing an alternating current power supply voltage; the voltage conversion unit is connected with the power supply unit and used for converting the alternating current power supply voltage and outputting direct current voltage; and the control detection unit is connected with the voltage conversion unit and used for detecting whether a short circuit phenomenon exists in the charging loop or not when the portable equipment is accessed, controlling the voltage value of the direct-current voltage switched and output by the voltage conversion unit according to a detection result, and controlling the connection state of a connection circuit between the control detection unit and the portable equipment so as to charge or stop charging the portable equipment. The invention has low cost, is universal and is easy to realize micro short circuit detection so as to carry out short circuit protection when the portable equipment is charged and improve the charging safety.

Description

Charging short-circuit protection circuit and method and power adapter

Technical Field

The present invention relates to the field of charging protection technologies, and in particular, to a charging short-circuit protection circuit, a charging short-circuit protection method, and a power adapter.

Background

With the increasing popularity of portable devices, such as mobile phones, telephone watches, tablet computers and other devices, the situation that a charging loop is slightly short-circuited in the charging process of the portable devices is increasing.

The micro short circuit is harmful, which may cause damage to the charging system, black burning of the charging interface, and excessive temperature fire. It is important to solve the problem of the micro short circuit of the charging loop.

However, in the market, the number of portable devices capable of detecting the micro short circuit of the charging loop is very small, and the conventional scheme is high in cost, complex in implementation and not universal, so that all portable devices cannot be suitable for use. At present, only a few mobile phone manufacturers on the market add a solution of charging circuit micro short circuit on a high-end flagship model, and the solution can only be applied to a single model and cannot be used universally.

The method comprises the following steps:

1. and manufacturing a special charging adapter, and simultaneously adding the MCU into the charging adapter and the portable equipment to realize real-time communication between the charger and the portable equipment.

2. And a mos switch is integrated in the charging adapter, so that the charging voltage output can be closed. The MCU in the charging adapter is required to have ADC detection and support the current detection function.

3. If the charging adapter and the portable device are connected, the MCU starts handshake communication, the MCU in the portable device informs the MCU in the charging adapter to shut down charging, and then the charging adapter is controlled to output 5V charging voltage or the charging voltage required by the portable device, and at the moment, the output current of the charging adapter is detected. If the output current of the charging adapter is detected to be larger than a certain value, such as 200mA or 300mA, the charging loop between the charging adapter and the portable device is judged to have a micro short circuit. Because the portable device has turned off the charging, the charging adapter output current should be small or 0 at this time.

The disadvantages of this current solution are as follows:

1. the cost is high, and hardware such as an MCU needs to be added to the charging adapter and the portable device.

2. The implementation difficulty is high, and a special handshake communication protocol needs to be customized to realize the communication between the charging adapter and the portable device.

3. A dedicated data line for supporting a communication function needs to be provided for the charging adapter, further increasing the cost.

4. The method is not universal, can only be used for special portable equipment, and cannot realize micro short circuit detection on all portable equipment.

5. Occupation space, need add relevant hardware such as MCU in portable equipment, this is very big to miniaturized portable equipment realization degree of difficulty, for example phone wrist-watch, bracelet etc..

Disclosure of Invention

The invention aims to provide a charging short-circuit protection circuit, a charging short-circuit protection method and a power adapter, which realize low-cost, universal and easily-realized micro short-circuit detection so as to carry out short-circuit protection when portable equipment is charged and improve charging safety.

The technical scheme provided by the invention is as follows:

the invention provides a charging short-circuit protection circuit, comprising:

the power supply unit is used for accessing an alternating current power supply voltage;

the voltage conversion unit is connected with the power supply unit and used for converting the alternating current power supply voltage and outputting direct current voltage;

and the control detection unit is connected with the voltage conversion unit and used for detecting whether a short circuit phenomenon exists in the charging loop or not when the portable equipment is accessed, controlling the voltage value of the direct-current voltage switched and output by the voltage conversion unit according to a detection result, and controlling the connection state of a connection circuit between the control detection unit and the portable equipment so as to charge or stop charging the portable equipment.

Further, the charging short-circuit protection circuit further includes: a switch unit provided at a connection line between a power adapter and the portable device; the control detection unit includes:

the access detection module is used for detecting whether the portable equipment is accessed for charging;

the control module is used for controlling the voltage conversion unit to switch and output the direct-current voltage with the magnitude of a first preset voltage value or a second preset voltage value;

the current detection module is used for switching the magnitude of the output direct-current voltage in the voltage conversion unit and detecting whether a short circuit phenomenon occurs in a charging loop when the portable equipment is connected to be charged;

the control module is further used for controlling the switch unit to be switched from a connection state to a disconnection state if the short circuit phenomenon of the charging loop is determined, so that the connection circuit is disconnected to stop charging; and if the short circuit phenomenon does not occur in the charging loop, controlling the switch unit to keep a connected state, and controlling the voltage conversion unit to switch and output the direct-current charging voltage so as to charge the portable equipment.

Further, the charging short-circuit protection circuit further includes: the current detection resistor is arranged, and an ID pin is arranged on a charging interface female seat of the power adapter; the ID pin is obtained by separating any pin of the grounding pin of the charging interface female socket from the rest pins; the access detection module comprises: a first access detection submodule; the current detection module includes: the device comprises a current detection submodule, a timing submodule and a processing submodule;

the control module is used for controlling the voltage conversion unit to output a preset direct current voltage in a default mode before detecting whether the portable equipment is connected to charge or not;

the access detection submodule is used for determining that the portable equipment is accessed and charged if the short circuit of the ID pin and the grounding pin of the portable equipment is detected;

the current detection submodule is connected with the current detection resistor and used for detecting whether the output current at the current detection resistor reaches a first preset current value or not when the voltage conversion unit outputs the preset direct-current voltage by default and portable equipment is charged;

the timing submodule is used for judging whether the duration of the output current reaching the first preset current value exceeds a first preset duration or not;

the processing submodule is further used for determining that a short circuit phenomenon occurs in the charging loop if the duration of the output current reaching the first preset current value exceeds the first preset duration; and if the duration of the output current not reaching the first preset current value exceeds the first preset duration, determining that the short circuit phenomenon does not occur in the charging loop.

Further, the charging short-circuit protection circuit further includes: a current detection resistor; the access detection module comprises: a second access detection sub-module; the current detection module includes: the device comprises a current detection submodule, a timing submodule and a processing submodule;

the control module is used for controlling the voltage conversion unit to output the DC charging voltage by default before detecting whether the portable equipment is connected to the charging;

the access detection submodule is connected with the current detection resistor and is used for determining that the access charging of the portable equipment exists when the voltage conversion unit outputs the direct-current charging voltage by default and the duration of the output current reaching a second preset current value at the current detection resistor exceeds a second preset duration;

the control module is used for controlling the voltage conversion unit to convert the output voltage from the direct current charging voltage to a preset direct current voltage when the portable equipment is determined to be charged;

the current detection submodule is connected with the current detection resistor and used for detecting whether the output current at the current detection resistor reaches a second preset current value or not when the voltage conversion unit outputs the preset direct-current voltage;

the timing submodule is used for judging whether the duration of the output current reaching the second preset current value exceeds a second preset duration or not;

the processing submodule is further used for determining that a short circuit phenomenon occurs in the charging loop if the duration of the output current reaching a second preset current value exceeds a second preset duration; and if the duration of the output current reaching the second preset current value does not exceed the second preset duration, determining that the short circuit phenomenon does not occur in the charging loop.

Further, the voltage conversion unit includes: the device comprises an alternating current and direct current conversion module, a first voltage conversion module and a second voltage conversion module;

the alternating current and direct current conversion module is used for converting the alternating current power supply voltage into direct current output voltage;

the first voltage conversion module is connected with the alternating current-direct current conversion module and used for carrying out voltage reduction processing on the direct current output voltage and outputting a preset direct current voltage;

the second voltage conversion module is connected with the alternating current-direct current conversion module and used for carrying out voltage reduction processing on the direct current output voltage and outputting direct current charging voltage;

and the voltage value of the preset direct current voltage is smaller than the voltage value of the direct current charging voltage.

The invention also provides a charging short-circuit protection method, which comprises the following steps:

detecting whether the portable equipment is connected for charging or not;

if the portable equipment is accessed, detecting whether a short circuit phenomenon exists in a charging loop;

and controlling the magnitude of the voltage value of the output direct-current voltage according to the detection result, and controlling the connection state of a connection line between the power adapter and the portable equipment so as to charge or stop charging the portable equipment.

Further, the power adapter includes: the current detection resistor is arranged, and an ID pin is arranged on a charging interface female seat of the power adapter; the ID pin is obtained by separating any pin of the grounding pin of the charging interface female socket from the rest pins; the method comprises the following steps before the portable equipment is detected whether charging is accessed, wherein the steps comprise:

controlling the self-default output of preset direct current voltage;

the step of detecting whether the portable equipment is connected to charge comprises the following steps:

detecting whether the ID pin is short-circuited with a grounding pin of the portable equipment;

if the ID pin is short-circuited with the grounding pin of the portable equipment, determining that the portable equipment is accessed for charging;

if the portable equipment is accessed, the step of detecting whether the short circuit phenomenon exists in the charging loop comprises the following steps:

detecting whether the output current at the current detection resistor reaches a first preset current value or not, and judging whether the duration of the output current reaching the first preset current value exceeds a first preset duration or not;

if the duration of the output current reaching the first preset current value exceeds the first preset duration, determining that a short circuit phenomenon occurs in the charging loop;

and if the duration of the output current not reaching the first preset current value exceeds the first preset duration, determining that the short circuit phenomenon does not occur in the charging loop.

Further, the power adapter includes: a current detection resistor; the method comprises the following steps before the portable equipment is detected whether charging is accessed, wherein the steps comprise:

when the self-default output direct-current charging voltage is controlled, whether the duration of the output current at the current detection resistor reaching a second preset current value exceeds a second preset duration is detected;

if the duration of the output current reaching the second preset current value exceeds the second preset duration, determining that the portable equipment is charged in an access mode;

after switching and outputting a preset direct current voltage, detecting whether the output current at the current detection resistor reaches a second preset current value again;

judging whether the duration of the output current reaching a second preset current value exceeds a second preset duration or not after the preset direct-current voltage is switched and output;

if the duration of the output current reaching the second preset current value exceeds the second preset duration after the preset direct-current voltage is switched and output, determining that a short circuit phenomenon occurs in the charging circuit;

and if the duration of the output current reaching the second preset current value does not exceed the second preset duration after the preset direct-current voltage is switched and output, determining that the short circuit phenomenon does not occur in the charging loop.

Further, the step of controlling the magnitude of the voltage value of the output dc voltage according to the detection result, and controlling the connection state of the connection line between the power adapter and the portable device, so as to charge or stop charging the portable device includes the steps of:

if the short circuit phenomenon of the charging loop is determined, the switch unit is controlled to be switched from a connection state to a disconnection state, so that the connection circuit is disconnected to stop charging;

if the short circuit phenomenon does not occur in the charging loop, controlling the switch unit to keep a connected state and controlling to output direct current charging voltage so as to charge the portable equipment;

wherein, the switch unit is arranged at a connecting line between the power adapter and the portable equipment.

The present invention also provides a power adapter comprising: the charger comprises a PCB and a charger body; the PCB is integrated with the charging short-circuit protection circuit.

The charging short-circuit protection circuit, the charging short-circuit protection method and the power adapter provided by the invention can be used for detecting a micro short circuit with low cost, universality and easiness in realization so as to carry out short-circuit protection when the portable equipment is charged and improve the charging safety.

Drawings

The above features, technical features, advantages and implementations of a charging short-circuit protection circuit, a method and a power adapter will be further described in the following detailed description of preferred embodiments in a clearly understandable manner with reference to the accompanying drawings.

Fig. 1 is a schematic structural diagram of an embodiment of a charging short-circuit protection circuit according to the present invention;

fig. 2 is a schematic structural diagram of another embodiment of a charging short-circuit protection circuit according to the present invention;

fig. 3 is a schematic structural diagram of another embodiment of a charging short-circuit protection circuit according to the present invention;

fig. 4 is a schematic structural diagram of another embodiment of a charging short-circuit protection circuit according to the present invention;

fig. 5 is a schematic structural diagram of another embodiment of a charging short-circuit protection circuit according to the present invention;

FIG. 6 is a flow chart of one embodiment of a charging short protection method of the present invention;

FIG. 7 is a schematic structural diagram of another embodiment of a charging short-circuit protection method according to the present invention;

fig. 8 is a schematic structural diagram of another embodiment of a charging short-circuit protection method according to the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items and includes such combinations.

In particular implementations, the mobile clients described in embodiments of the present application include, but are not limited to, other portable devices such as mobile phones, laptops, or tablets having touch-sensitive surfaces (e.g., touch screen displays and/or touch pads).

The mobile client supports various applications, such as one or more of the following: a drawing application, a presentation application, a network creation application, a word processing application, a disc burning application, a spreadsheet application, a gaming application, a telephone application, a video conferencing application, an email application, an instant messaging application, an exercise support application, a photo management application, a digital camera application, a digital video camera application, a Web browsing application, a digital music player application, and/or a digital video player application.

In addition, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

In one embodiment of the present invention, as shown in fig. 1, a charging short-circuit protection circuit includes:

a power supply unit U0 for accessing an ac supply voltage;

specifically, the input ac power supply voltage is an ac power with a set voltage value. The input ac supply voltage is typically 220V mains. A first power input interface of the power supply unit U0 is connected with a live wire, and a second power input interface is connected with a zero wire.

The voltage conversion unit U2 is connected with the power supply unit U0 and is used for converting the alternating current power supply voltage and outputting direct current voltage;

and the control detection unit U1 is connected with the voltage conversion unit U2 and is used for detecting whether a short circuit phenomenon exists in the charging loop if the portable device U3 is connected, controlling the voltage value of the direct-current voltage switched and output by the voltage conversion unit U2 according to the detection result, and controlling the connection state of a connection line between the control detection unit U2 and the portable device U3 so as to charge or stop charging the portable device U3.

Specifically, in this embodiment, after the power adapter end detects that the portable device U3 is connected, the short-circuit phenomenon is detected, the voltage value of the dc voltage output by switching the voltage conversion unit U2 is controlled according to the detection result, and the connection state of the connection line between the power adapter end and the portable device U3 is controlled, so that the charging or the stopping of the charging is performed on the portable device U3, the problems of damage to the charging system due to a micro short circuit, blackness of the charging interface, over-temperature fire and the like are avoided, and the charging safety of the power adapter and the charged portable device U3 is greatly protected.

According to the invention, after the power adapter end detects that the portable equipment U3 is connected, the short-circuit phenomenon is detected, the voltage value of the direct-current voltage switched and output by the voltage conversion unit U2 is controlled according to the detection result, and the connection state of the connection line between the power adapter end and the portable equipment U3 is controlled, so that the portable equipment U3 is charged or stopped to be charged, all the portable equipment U3 to be charged can be used universally, and the problem of universality of micro short-circuit detection is solved. Whether a short circuit phenomenon exists in the charging loop is detected by controlling the detection unit U1, and related hardware such as an MCU (microprogrammed control Unit) does not need to be added into the portable device U3 to be charged. And the power adapter is controlled to output the required charging voltage after the power adapter and the portable device U3 to be charged establish communication through customizing a special handshake communication protocol.

In addition, the invention only needs to add related devices at the power adapter end and process at the power adapter end, thereby reducing the cost, solving the space problem of the portable device U3 to be charged, needing no complex communication protocol and reducing the realization difficulty. Since the portable device U3 to be charged does not need to communicate with the power adapter to notify that charging is turned off, a dedicated data line does not need to be provided for the power adapter, and this micro short detection function can be realized only by a data line having a positive electrode and a negative electrode. The invention can realize low-cost, universal and easily realized micro short circuit detection so as to carry out short circuit protection when charging the portable device U3 and improve the charging safety.

Based on the foregoing embodiment, the charging short-circuit protection circuit further includes: a switch unit provided at a connection line between the power adapter and the portable device U3; as shown in fig. 2, the control detection unit U1 includes:

an access detection module 210, configured to detect whether there is an access charging of the portable device U3;

the control module 220 is configured to control the voltage conversion unit U2 to switch and output a dc voltage with a first preset voltage value or a second preset voltage value;

the current detection module 230 is configured to detect whether a short circuit phenomenon occurs in the charging loop when the voltage conversion unit U2 switches the magnitude of the output dc voltage and detects that charging is performed when the portable device U3 is connected;

the control module 220 is further configured to control the switch unit to switch from the connected state to the disconnected state if it is determined that the short circuit phenomenon occurs in the charging loop, so that the connection line is disconnected to stop charging; if the short circuit phenomenon does not occur in the charging loop, the control switch unit is kept in a connected state, and the control voltage conversion unit U2 is controlled to switch and output the direct current charging voltage so as to charge the portable device U3.

Specifically, the same parts in this embodiment as those in the above embodiments are not described in detail. The switch unit includes a contact switch or a MOS switch (i.e., an N-type MOS transistor Q1), and the like, and can implement a switch that switches between an off state and an on state according to a signal.

Specifically, in this embodiment, after the power adapter detects that the portable device U3 is connected, the power adapter detects a short-circuit phenomenon, and if it is determined that the charging loop has the short-circuit phenomenon, the control switch unit is switched from the connected state to the disconnected state, so that the connection line is disconnected to stop charging. If the short circuit phenomenon of the charging loop is determined not to occur, the control switch unit is kept in a connected state, and the control voltage conversion unit U2 is controlled to switch and output the direct current charging voltage so as to charge the portable device U3. The problems of damage of a charging system, blackness of a charging interface, over-temperature fire and the like caused by micro short circuit are avoided, so that the charging safety of the power adapter and the charged portable device U3 is greatly protected.

Based on the foregoing embodiment, as shown in fig. 3, the charging short-circuit protection circuit further includes: the current detection resistor R1 is arranged, and an ID pin is arranged on a charging interface female seat of the power adapter; the ID pin is obtained by separating any pin of the grounding pin of the charging interface female socket from the rest pins; the access detection module 210 includes: a first access detection submodule; the current detection module 230 includes: the device comprises a current detection submodule, a timing submodule and a processing submodule;

the control module 220 is configured to control the voltage conversion unit U2 to output a preset dc voltage by default before detecting whether the portable device U3 is charged;

the access detection submodule is used for determining that the portable equipment U3 is accessed for charging if the short circuit of the ID pin and the grounding pin of the portable equipment U3 is detected;

the current detection submodule is connected with the current detection resistor R1 and used for detecting whether the output current at the current detection resistor R1 reaches a first preset current value or not when the voltage conversion unit U2 outputs a preset direct-current voltage by default and the portable device U3 is charged;

the processing submodule is also used for determining that the short circuit phenomenon occurs in the charging loop if the duration of the output current reaching the first preset current value exceeds the first preset duration; and if the duration of the output current not reaching the first preset current value exceeds the first preset duration, determining that the short circuit phenomenon does not occur in the charging loop.

Specifically, as shown in fig. 3, the left side is a power adapter side, and the right side is a portable device U3 to be charged.

Most portable device U3 at present, such as cell-phone, flat panel, phone wrist-watch, bracelet, treasured that charges etc. its charging voltage (Vbus) must be higher than a definite value and can charge, and the minimum charging voltage (Vbus) to portable device U3 in the industry is 3V at present, and power adapter can charge to the portable device U3 of acceping when being higher than 3.5V. In other words, if the charging voltage (Vbus) output by the power adapter is lower than a voltage of 3.5V, such as 3V. The power adapter does not charge the internal battery of the connected portable device U3 to be charged, and we are required to modify the power adapter.

A control detection unit U1, an N-type MOS tube Q1 and a current detection resistor R1 are added at the end of the power adapter.

The N-type MOS tube Q1 has the following functions: the shutdown of the power adapter output may be achieved. Normally, the power adapter is turned on by default, and the power adapter can be turned off under the control of the control detection unit U1 when detecting the occurrence of the micro short circuit phenomenon.

The current detection resistor R1 functions as: the control detection unit U1 detects a first voltage difference between two ends of the resistor R1 at the current moment through the detection current, and calculates according to the first voltage difference and the resistance value of the detection current detection resistor R1, so that the output current of the power adapter at the current moment is detected.

Controlling the function of the detection unit U1: the output voltage of the power adapter can be controlled through a control line, the output voltage of the power adapter is detected, the on and off of the N-type MOS tube Q1 are controlled, and the output current of the power adapter is read. Meanwhile, whether the portable device U3 to be charged is accessed or not can be detected through the ID pin.

Preferably, the charging short-circuit protection circuit further includes: the temperature-sensitive resistor R2 (the resistance of the temperature-sensitive resistor R2 increases with increasing temperature). The control detection unit U1 obtains the temperature of the power adapter at the current moment according to the second voltage difference and the resistance value of the temperature-sensitive resistor R2 by detecting the second voltage difference at two ends of the temperature-sensitive resistor R2 at the current moment. Once the temperature of the power adapter at the current moment is greater than the preset temperature value, the switch unit can be controlled to be switched from the connection state to the disconnection state, so that the connection line is disconnected to stop charging. Therefore, the charging temperature of the power adapter can be protected from being too high, and the service lives of the power adapter and the portable device U3 to be charged are prolonged.

The control module 220 controls the power adapter to output a preset direct current voltage (including 3V or 2V or 2.5V optional) by default. When the portable device U3 to be charged is plugged in, it is possible to detect that there is a device connected by detecting whether the ID pin is pulled to the ground pin (GND), i.e., detecting that the ID pin is shorted to the ground pin.

When the portable device U3 to be charged is detected to be connected, the output current of the power adapter is immediately started to be detected, if the output current is smaller than a certain value within a certain time, the portable device U3 is connected for charging, and the duration that the output current at the current detection resistor R1 does not reach the first preset current value does not exceed the first preset time, it is determined that the short circuit phenomenon does not occur in the charging loop. For example, if the output current at the continuous 1S current detection resistor R1 is less than 300mA (or 200mA), it is determined that the charging loop is not short-circuited, and then the control module 220 controls the N-type MOS transistor Q1 to be turned on, i.e., controls the N-type MOS transistor Q1 to be kept in a connected state, and controls the voltage conversion unit U2 to switch the output dc charging voltage (e.g., a dc voltage of 5V), so as to start normal charging for charging the portable device U3.

When the portable device U3 to be charged is detected to be connected, the output current of the power adapter is immediately started to be detected, if the output current is larger than or equal to a certain value within a certain time, the portable device U3 is connected for charging, and the duration of the output current at the current detection resistor R1 reaching a first preset current value exceeds a first preset duration, and the short circuit phenomenon of the charging loop is determined. For example, if the output current at the continuous 1S current detection resistor R1 is greater than or equal to 300mA (or 200mA), it is considered that the charging loop has a short circuit, and then the control module 220 controls the N-type MOS transistor Q1 to close, i.e., controls the N-type MOS transistor Q1 to switch from the connected state to the disconnected state, so that the connection line is disconnected to stop charging.

The female seat of power adapter's the interface that charges includes USB interface and Type-C interface that charges. In order to make the ID pin universal, as shown in fig. 4, a charging interface female socket of the power adapter is modified, a ground pin of the charging interface female socket (for example, a USB female socket) is divided into a small pin, so that any pin of the ground pin of the charging interface female socket is separated from the rest pins, the separated pin is used as the ID pin, when an external portable device U3 to be charged is connected, the ID pin is short-circuited with the ground pin of the portable device U3, and then the function of connection and charging detection of the external portable device U3 to be charged is determined.

Specifically, in this embodiment, if the power adapter end detects that the ID pin and the ground pin of the portable device U3 are short-circuited, it is determined that the portable device U3 is connected, and then the power adapter end performs detection of a short-circuit phenomenon, and if the duration of the output current at the current detection resistor R1 reaching the first preset current value exceeds the first preset duration, it is determined that the short-circuit phenomenon occurs in the charging loop, the control switch unit is switched from the connected state to the disconnected state, so that the connection line is disconnected to stop charging. If the duration that the output current at the current detection resistor R1 does not reach the first preset current value exceeds the first preset duration, and when the short circuit phenomenon of the charging loop is determined not to occur, the control switch unit is kept in a connected state, and the voltage conversion unit U2 is controlled to switch and output the direct current charging voltage so as to charge the portable device U3. The problems of damage of a charging system, blackness of a charging interface, over-temperature fire and the like caused by micro short circuit are avoided, so that the charging safety of the power adapter and the charged portable device U3 is greatly protected.

According to the invention, after the power adapter end detects that the portable equipment U3 is connected, the short-circuit phenomenon is detected, the voltage value of the direct-current voltage switched and output by the voltage conversion unit U2 is controlled according to the detection result, and the connection state of the connection line between the power adapter end and the portable equipment U3 is controlled, so that the portable equipment U3 is charged or stopped to be charged, all the portable equipment U3 to be charged can be used universally, and the problem of universality of micro short-circuit detection is solved.

Moreover, only relevant devices need to be added at the power adapter end, and the power adapter end is processed, so that the cost is reduced, the problem of the space of the portable device U3 to be charged is solved, a complex communication protocol is not needed, and the implementation difficulty is reduced. Since the portable device U3 to be charged does not need to communicate with the power adapter to notify that charging is turned off, a dedicated data line does not need to be provided for the power adapter, and this micro short detection function can be realized only by a data line having a positive electrode and a negative electrode. The invention can realize low-cost, universal and easily realized micro short circuit detection so as to carry out short circuit protection when charging the portable device U3 and improve the charging safety.

Based on the foregoing embodiment, as shown in fig. 5, the charging short-circuit protection circuit further includes: a current detection resistor R1; the access detection module 210 includes: a second access detection sub-module; the current detection module 230 includes: the device comprises a current detection submodule, a timing submodule and a processing submodule;

the control module 220 is configured to control the voltage conversion unit U2 to output the dc charging voltage by default before detecting whether the portable device U3 is connected to the charging unit;

the access detection submodule is connected with the current detection resistor R1 and is used for determining that the portable device U3 is accessed for charging when the duration of the output current of the current detection resistor R1 reaching a second preset current value exceeds a second preset duration when the voltage conversion unit U2 outputs the DC charging voltage by default;

the control module 220 is configured to control the voltage conversion unit U2 to switch the output voltage from the dc charging voltage to a preset dc voltage when it is determined that charging access to the portable device U3 exists;

the current detection submodule is connected with the current detection resistor R1 and is used for detecting whether the output current at the current detection resistor R1 reaches a second preset current value or not when the voltage conversion unit U2 outputs a preset direct-current voltage;

the processing submodule is also used for determining that the short circuit phenomenon occurs in the charging loop if the duration of the output current reaching the second preset current value exceeds the second preset duration; and if the duration of the output current reaching the second preset current value does not exceed the second preset duration, determining that the short circuit phenomenon does not occur in the charging loop.

Specifically, as shown in fig. 5, the left side is a power adapter side, and the right side is a portable device U3 to be charged. The same parts in this embodiment as those in the above embodiments are not described in detail herein.

The control module 220 controls the power adapter to output a charging dc voltage (e.g., 5V) by default. When the portable device U3 to be charged is plugged in, whether an external charging device is connected can be determined by detecting whether there is a charging current (i.e., whether there is an output current in the power adapter for a period of time), that is, when the duration of the output current at the current detection resistor R1 reaching the second preset current value (a current value greater than 0mA) exceeds the second preset duration, it is determined that there is a charged portable device U3 connected.

When it is detected that the portable device U3 to be charged is connected, the control module 220 controls the power adapter to switch the output voltage from the dc charging voltage to a preset dc voltage (including 3V or 2V or 2.5V is optional), and then when the power adapter outputs the dc charging voltage and a duration that the output current at the current detection resistor R1 does not reach a first preset current value does not exceed the first preset duration, it is determined that a short circuit phenomenon does not occur in the charging loop. For example, if the output current at the continuous 1S current detection resistor R1 is less than 300mA (or 200mA), it is determined that the charging loop is not short-circuited, and then the control module 220 controls the N-type MOS transistor Q1 to be turned on, i.e., controls the N-type MOS transistor Q1 to be kept in a connected state, and controls the voltage conversion unit U2 to switch the output dc charging voltage (e.g., a dc voltage of 5V), so as to start normal charging for charging the portable device U3.

When it is detected that the portable device U3 to be charged is connected, the control module 220 controls the power adapter to switch the output voltage from the dc charging voltage to a preset dc voltage (including 3V or 2V or 2.5V is optional), and then when the power adapter outputs the dc charging voltage and a duration of an output current at the current detection resistor R1 reaching a first preset current value exceeds a first preset duration, it is determined that a short circuit occurs in the charging loop. For example, if the output current at the continuous 1S current detection resistor R1 is greater than or equal to 300mA (or 200mA), it is considered that the charging loop has a short circuit, and then the control module 220 controls the N-type MOS transistor Q1 to close, i.e., controls the N-type MOS transistor Q1 to switch from the connected state to the disconnected state, so that the connection line is disconnected to stop charging.

Specifically, in this embodiment, the power adapter end detects the charging current when the portable device U3 is connected for charging, and then determines that the portable device U3 is connected, and then, the power adapter end detects a short-circuit phenomenon, and if the duration of the output current at the current detection resistor R1 reaching the first preset current value exceeds the first preset duration, determines that the charging loop has a short-circuit phenomenon, the control switch unit switches from the connected state to the disconnected state, so that the connection line is disconnected to stop charging. If the duration that the output current at the current detection resistor R1 does not reach the first preset current value exceeds the first preset duration, and when the short circuit phenomenon of the charging loop is determined not to occur, the control switch unit is kept in a connected state, and the voltage conversion unit U2 is controlled to switch and output the direct current charging voltage so as to charge the portable device U3. The problems of damage of a charging system, blackness of a charging interface, over-temperature fire and the like caused by micro short circuit are avoided, so that the charging safety of the power adapter and the charged portable device U3 is greatly protected.

Moreover, only relevant devices need to be added at the power adapter end, and the power adapter end is processed, so that the cost is reduced, the problem of the space of the portable device U3 to be charged is solved, a complex communication protocol is not needed, and the implementation difficulty is reduced. Since the portable device U3 to be charged does not need to communicate with the power adapter to notify that charging is turned off, a dedicated data line does not need to be provided for the power adapter, and this micro short detection function can be realized only by a data line having a positive electrode and a negative electrode. The invention can realize low-cost, universal and easily realized micro short circuit detection so as to carry out short circuit protection when charging the portable device U3 and improve the charging safety. In addition, this embodiment need not reform transform the female seat of the interface that charges of power adapter, owing to need not reform transform the female seat of the interface that charges of power adapter for short-circuit protection's realization cost is lower.

Based on the foregoing embodiment, the voltage conversion unit U2 includes: the device comprises an alternating current and direct current conversion module, a first voltage conversion module and a second voltage conversion module;

the alternating current-direct current conversion module is used for converting alternating current supply voltage into direct current output voltage;

the voltage value of the preset direct current voltage is smaller than the voltage value of the direct current charging voltage.

When the output end of the charging protection circuit is short-circuited, the value of the current flowing through the current detection resistor R1 in the charging loop is increased, so that the voltage at the two ends of the current detection resistor R1 is increased, the gate-source voltage difference of the N-type MOS transistor Q1 in the charging protection circuit is rapidly reduced, and the gate-source voltage difference of the N-type MOS transistor Q1 is rapidly reduced, so that the N-type MOS transistor Q1 is cut off, that is, the connection line between the charging protection circuit and the portable device U3 is disconnected to stop charging. When the output end of the charging protection circuit is not short-circuited, the output voltage of the charging protection circuit is the voltage during charging operation, so that the N-type MOS transistor Q1 is turned on, and the voltage conversion unit U2 is controlled to switch and output the direct-current charging voltage to charge the portable device U3.

When the charging protection circuit is short-circuited, the power adapter stops charging by controlling the cut-off of the N-type MOS tube Q1. Therefore, when the charging protection circuit is short-circuited, the power adapter can be effectively protected to realize short-circuit protection, the charging protection circuit is simple and reliable, the response speed is high, the circuit cost can be effectively saved, the power adapter cannot be damaged due to short circuit, the service life of the power adapter is prolonged, and the maintenance cost is saved.

When the short circuit appears through the protection circuit that charges in this embodiment, through control N type MOS pipe Q1 ending, power adapter stops to charge to can in time stop power adapter when taking place the short circuit to portable equipment U3's charging, improve the security greatly, avoid the loss of property.

In an embodiment of the present invention, as shown in fig. 6, a charging short-circuit protection method includes:

s100, detecting whether the portable device U3 is charged or not;

S200, if the portable device U3 is connected, detecting whether a short circuit phenomenon exists in a charging loop;

s300, according to the detection result, the voltage value of the output direct-current voltage is controlled, and the connection state of a connection line between the power adapter and the portable device U3 is controlled, so that the portable device U3 is charged or the charging is stopped.

In an embodiment of the present invention, as shown in fig. 7, a charging short-circuit protection method includes: the power adapter includes: the current detection resistor R1 is arranged, and an ID pin is arranged on a charging interface female seat of the power adapter; the ID pin is obtained by separating any pin of the grounding pin of the charging interface female socket from the rest pins;

s010 controls the self to output a preset direct current voltage by default;

s111, detecting whether the ID pin is short-circuited with a grounding pin of the portable device U3;

s121, if the ID pin is short-circuited with the grounding pin of the portable device U3, determining that charging is accessed by the portable device U3;

s211 detects whether the output current at the current detection resistor R1 reaches a first preset current value, and determines whether a duration of the output current reaching the first preset current value exceeds a first preset duration;

s221, if the duration of the output current reaching the first preset current value exceeds the first preset duration, determining that a short circuit phenomenon occurs in the charging loop;

s231, if the duration of the output current not reaching the first preset current value exceeds the first preset duration, determining that the short circuit phenomenon does not occur in the charging loop;

s310, if the short circuit phenomenon of the charging loop is determined, the switch unit is controlled to be switched from a connection state to a disconnection state, and the connection line is disconnected to stop charging;

s320, if the short circuit phenomenon does not occur in the charging loop, controlling the switch unit to keep a connected state, and controlling to output direct current charging voltage so as to charge the portable device U3;

wherein, the switch unit is arranged at the connecting line between the power adapter and the portable device U3.

Specifically, the switch unit includes a contact switch or a MOS switch (i.e., an N-type MOS transistor Q1), and the like, and the switch that can switch between an off state and an on state is implemented according to a signal. Parts in this embodiment that are the same as those in the above embodiments are not described in detail. As shown in fig. 3, the left side is the power adapter side and the right side is the portable device U3 to be charged.

In an embodiment of the present invention, as shown in fig. 8, a charging short-circuit protection method includes: the power adapter includes: the current detection resistor R1 is arranged, and an ID pin is arranged on a charging interface female seat of the power adapter; the ID pin is obtained by separating any pin of the grounding pin of the charging interface female socket from the rest pins;

s020 controls the self to output a direct current charging voltage in a default mode;

s112, detecting whether the duration of the output current at the current detection resistor R1 reaching the second preset current value exceeds a second preset duration;

s122, if the duration of the output current reaching the second preset current value exceeds the second preset duration, determining that charging is accessed to the portable device U3;

s212, switching to output a preset dc voltage, and then detecting whether the output current at the current detection resistor R1 reaches a second preset current value;

s222, judging whether the duration of the output current reaching the second preset current value exceeds a second preset duration or not after the preset direct-current voltage is switched and output;

s232, if the duration of the output current reaching the second preset current value exceeds the second preset duration after the preset direct-current voltage is switched and output, determining that a short circuit phenomenon occurs in the charging loop;

s242, determining that the charging circuit is not short-circuited if the duration of the output current reaching the second preset current value does not exceed the second preset duration after the preset dc voltage is switched to be output;

Specifically, as shown in fig. 5, the left side is a power adapter side, and the right side is a portable device U3 to be charged. The same parts as those in the above embodiments are not described in detail. Specifically, the switch unit includes a contact switch or a MOS switch (i.e., an N-type MOS transistor Q1), and the like, and the switch that can switch between an off state and an on state is implemented according to a signal. Parts in this embodiment that are the same as those in the above embodiments are not described in detail.

In the above embodiment, the first preset duration and the second preset duration are not limited, and are set according to requirements and experience.

In one embodiment of the present invention, a power adapter includes: the charger comprises a PCB and a charger body; the PCB is integrated with a charging short-circuit protection circuit according to any one of the embodiments corresponding to the above-mentioned figures 1-5.

It should be noted that the above embodiments can be freely combined as necessary. The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and improvements can be made without departing from the principle of the present invention, and these modifications and improvements should also be construed as the protection scope of the present invention.

Claims

1. a charging short-circuit protection circuit, is characterized in that, comprises:

The power supply unit is used to connect to the AC power supply voltage;

a voltage conversion unit, connected to the power supply unit, for converting the AC power supply voltage and outputting a DC voltage;

a control detection unit, connected to the voltage conversion unit, for detecting whether there is a short circuit in the charging circuit when a portable device is connected, and controlling the voltage value of the DC voltage output by the switching of the voltage conversion unit according to the detection result, And control the connection state of the connection line between itself and the portable device, so as to charge or stop charging the portable device.

2 . The charging short-circuit protection circuit according to claim 1 , wherein the charging short-circuit protection circuit further comprises: a switch unit arranged at the connecting line between the power adapter and the portable device; the control detection unit include:

The access detection module is used to detect whether there is a portable device connected for charging;

a control module, configured to control the voltage conversion unit to switch and output a DC voltage whose magnitude is a first preset voltage value or a second preset voltage value;

a current detection module, configured to detect whether a short circuit occurs in the charging circuit when the voltage conversion unit switches the magnitude of the output DC voltage and detects that the portable device is connected for charging;

The control module is further configured to control the switch unit to switch from the connected state to the disconnected state if it is determined that a short circuit occurs in the charging circuit, so that the connection line is disconnected to stop charging; if it is determined that the charging circuit is not short-circuited When the phenomenon occurs, the switch unit is controlled to maintain a connected state, and the voltage conversion unit is controlled to switch and output a DC charging voltage to charge the portable device.

3. The charging short-circuit protection circuit according to claim 2, wherein the charging short-circuit protection circuit further comprises: a current detection resistor, and the charging interface socket of the power adapter is provided with an ID pin; the ID The pin is any lead pin of the ground pin of the charging interface female base and obtained separately from the other lead pins; the access detection module includes: a first access detection sub-module; the current detection module includes: current detection submodules, timing submodules and processing submodules;

The control module is configured to control the voltage conversion unit to output a preset DC voltage by default before detecting whether the portable device is connected to charging;

The access detection sub-module is used to determine that there is a portable device for access charging if it is detected that the ID pin is short-circuited with the ground pin of the portable device;

The current detection sub-module is connected to the current detection resistor, and is configured to detect the output current at the current detection resistor when the voltage conversion unit outputs the preset DC voltage by default and there is a portable device connected for charging Whether the first preset current value is reached;

The timing sub-module is used for judging whether the duration for which the output current reaches the first preset current value exceeds the first preset duration;

The processing sub-module is further configured to determine that a short circuit occurs in the charging circuit if the duration for which the output current reaches the first preset current value exceeds the first preset duration; if the output current does not reach the first preset value When the duration of the current value exceeds the first preset duration, it is determined that there is no short circuit in the charging circuit.

4 . The charging short-circuit protection circuit according to claim 2 , wherein the charging short-circuit protection circuit further comprises: a current detection resistor; the access detection module comprises: a second access detection sub-module; the current The detection module includes: a current detection sub-module, a timing sub-module and a processing sub-module;

The control module is configured to control the voltage conversion unit to output a DC charging voltage by default before detecting whether the portable device is connected to charging;

The access detection sub-module is connected to the current detection resistor, and is used for detecting that the output current at the current detection resistor reaches a second preset current value when the voltage conversion unit outputs the DC charging voltage by default When the duration exceeds the second preset duration, it is determined that there is a portable device connected to charging;

the control module, configured to control the voltage conversion unit to switch the output voltage from the DC charging voltage to a preset DC voltage when it is determined that the portable device is connected to charging;

The current detection sub-module is connected to the current detection resistor, and is used for detecting whether the output current at the current detection resistor reaches a second preset current value when the voltage conversion unit outputs the preset DC voltage ;

The timing sub-module is used for judging whether the duration for which the output current reaches the second preset current value exceeds the second preset duration;

The processing sub-module is further configured to determine that a short circuit occurs in the charging circuit if the duration for which the output current reaches the second preset current value exceeds the second preset duration; if the output current reaches the second preset current When the duration of the value does not exceed the second preset duration, it is determined that there is no short circuit in the charging circuit.

5. The charging short-circuit protection circuit according to any one of claims 1-4, wherein the voltage conversion unit comprises: an AC-DC conversion module, a first voltage conversion module and a second voltage conversion module;

The AC-DC conversion module is used to convert the AC power supply voltage into a DC output voltage;

The first voltage conversion module is connected to the AC-DC conversion module, and is configured to perform step-down processing on the DC output voltage to output a preset DC voltage;

The second voltage conversion module is connected to the AC-DC conversion module, and is configured to perform step-down processing on the DC output voltage to output a DC charging voltage;

Wherein, the voltage value of the preset DC voltage is smaller than the voltage value of the DC charging voltage.

6. A charging short-circuit protection method, comprising the steps of:

Detect whether there is a portable device connected for charging;

If there is a portable device connected, check whether there is a short circuit in the charging circuit;

The magnitude of the output DC voltage is controlled according to the detection result, and the connection state of the connection line between the power adapter and the portable device is controlled, so as to charge or stop charging the portable device.

7. The charging short-circuit protection method according to claim 6, wherein the power adapter comprises: a current detection resistor, and the charging interface socket of the power adapter is provided with an ID pin; the ID pin is Any lead pin of the grounding pin of the charging interface female base is obtained by separating it from the other lead pins; before the detection of whether there is a portable device connected to charging includes the steps:

Control its own default output preset DC voltage;

The detecting whether there is a portable device connected to charging includes the steps:

Detecting whether the ID pin and the ground pin of the portable device are short-circuited;

If the ID pin is short-circuited with the ground pin of the portable device, it is determined that there is a portable device connected to charging;

If there is a portable device connected, detecting whether there is a short circuit in the charging circuit includes the steps:

Detecting whether the output current at the current detection resistor reaches a first preset current value, and judging whether the duration for which the output current reaches the first preset current value exceeds a first preset time length;

If the duration for which the output current reaches the first preset current value exceeds the first preset duration, it is determined that a short circuit occurs in the charging circuit;

If the duration for which the output current does not reach the first preset current value exceeds the first preset duration, it is determined that there is no short circuit phenomenon in the charging circuit.

8 . The charging short-circuit protection method according to claim 6 , wherein the power adapter comprises: a current detection resistor; before the detection of whether there is a portable device connected to charging comprises the steps of: 9 .

Control its own default output DC charging voltage;

Detecting whether the duration for which the output current at the current detection resistor reaches the second preset current value exceeds the second preset duration;

If the duration for which the output current reaches the second preset current value exceeds the second preset duration, it is determined that there is a portable device connected for charging;

After switching the output preset DC voltage, detect again whether the output current at the current detection resistor reaches the second preset current value;

judging whether the duration for which the output current reaches the second preset current value exceeds the second preset duration after switching the output preset DC voltage;

If, after switching the output preset DC voltage, the output current reaches the second preset current value for a duration exceeding the second preset duration, it is determined that a short circuit occurs in the charging circuit;

If the output current reaches the second preset current value after the switching of the output preset DC voltage and the duration for which the output current reaches the second preset current value does not exceed the second preset time period, it is determined that there is no short circuit in the charging circuit.

9. The charging short-circuit protection method according to claim 6, wherein the voltage value of the output DC voltage is controlled according to the detection result, and the connection state of the connection line between the power adapter and the portable device is controlled, In order to charge or stop charging the portable device comprises the steps of:

If it is determined that a short circuit occurs in the charging circuit, the switch unit is controlled to switch from the connected state to the disconnected state, so that the connection line is disconnected to stop charging;

If it is determined that the charging circuit is not short-circuited, the switch unit is controlled to maintain a connected state, and the output DC charging voltage is controlled to charge the portable device;

Wherein, the switch unit is arranged at the connection line between the power adapter and the portable device.

10. A power adapter, comprising: a PCB board and a charger body; the PCB board is integrated with any one of 1-5 charging short-circuit protection circuits.