CN106300563A - USB power supply protection circuit and use the vehicle intelligent charging device of this circuit - Google Patents

Abstract

The invention relates to a USB power supply protection circuit and a vehicle-mounted intelligent charging device adopting the circuit. The circuit includes a voltage control interrupt port, a first voltage input port and a voltage acquisition port, the first voltage input port is connected with a parallel resistor, the output end of the parallel resistor is connected with the C collector of the first triode, the first three The B base of the transistor is connected to the voltage control interrupt port, the E emitter of the first triode is respectively connected to the first adjustable resistor and the B base of the second triode, and the C collector of the second triode is connected to the voltage The collection port is connected, and the output terminal of the first adjustable resistor and the E emitter of the second triode are both connected to the ground wire. Due to the existence of the USB power supply protection circuit, the existence of the circuit can effectively prevent the external charging device from exploding due to abnormality in the charging process, and prevent damage to the life and property of the user.

Description

USB power supply protection circuit and vehicle intelligent charging device adopting the circuit

technical field

The invention relates to the technical field of automotive electronics, in particular to a USB power supply protection circuit and a vehicle-mounted intelligent charging device using the circuit.

Background technique

An on-board USB charger is disclosed in the existing Chinese patent database, which includes a charger shell and a circuit control board placed inside the shell. Plug, the circuit control board inside the charger is also provided with a power plug that can be connected to an external power supply. Its disadvantages are: because the charger does not intelligently manage the charging process of the mobile phone, the battery will become hot when the mobile phone is charging. The user's life and property constitute a major safety hazard.

Contents of the invention

The purpose of the present invention is to provide a USB power supply protection circuit for preventing the battery from overheating and exploding when the mobile phone is charged.

In order to achieve the purpose of the above invention, the present invention is the technical solution adopted by the USB power supply protection circuit:

The USB power supply protection circuit includes a voltage control interrupt port, a first voltage input port and a voltage acquisition port, the first voltage input port is connected to a parallel resistor, and the output end of the parallel resistor is connected to the C collector of the first triode, The B base of the first triode is connected to the voltage control interrupt port, the E emitter of the first triode is respectively connected to the first adjustable resistor and the B base of the second triode, and the C set of the second triode The electrodes are connected to the voltage acquisition port, the output terminal of the first adjustable resistor is connected to the ground wire with the E emitter of the second triode, the first voltage input port is connected to the 12V power supply, and the voltage control interrupt port It is high level during normal operation, outputting 5V voltage, adjusting the resistance value of the first adjustable resistor, and limiting the passing current. When the current passing through the first adjustable resistor exceeds the limit value, and the voltage at both ends of the first adjustable resistor When it exceeds 0.7V, the second triode is turned on, and the voltage acquisition port receives a low-level signal, which is judged as overcurrent, and the voltage control interrupt port cuts off the USB power supply.

Compared with the prior art, the present invention has the beneficial effects of: due to the existence of the circuit, the external charging device can be effectively prevented from exploding due to abnormalities in the charging process, and damage to the lives and properties of users can be prevented.

Further, a second adjustable resistor is connected between the voltage control interrupt port and the B base of the first triode.

Further, a third adjustable resistor is connected between the voltage collection port and the C collector of the second triode.

Further, the collector C of the second triode is connected to a second voltage input port via a fourth adjustable resistor, and the second voltage input port is connected to a 5V power supply.

The present invention also provides a vehicle-mounted intelligent charging device adopting the USB power supply protection circuit, and the adopted technical solution:

The on-vehicle intelligent charging device adopting the USB power supply protection circuit includes a SOC microprocessor for mobile phone charging management, the SOC microprocessor is connected with a USB interface and a display screen of peripherals, and the SOC microprocessor is also connected with a USB The voltage of the power supply protection circuit controls the interruption port and the voltage acquisition port, and the USB interface is connected with the first voltage input port of the USB power supply protection circuit.

When the present invention works, the mobile phone is connected to the USB interface for charging earlier, the SOC microprocessor sends the AT command to read the battery information to the mobile phone through the USB interface, and the mobile phone receives the AT command to feed back the battery information (battery status, battery power, power level) , battery health status, battery voltage and battery temperature, etc.), the mobile phone battery information is displayed on the display screen, the SOC microprocessor dynamically monitors the charging of the mobile phone battery according to the battery information, and the USB power supply protection circuit monitors the voltage and current of the charging device Monitoring, when charging overcurrent, overvoltage or battery temperature is too high, the SOC microprocessor cuts off the power supply. Compared with the prior art, the beneficial effect of the present invention is: due to the existence of the USB power supply protection circuit, the charging process of the battery of the mobile phone can be effectively monitored, and the power supply can be cut off when the battery of the mobile phone is too hot. Intuitively check the battery information during the charging process of the mobile phone, and can artificially cut off the power supply in time, which improves the safety.

Further, the SOC microprocessor is also connected with a speaker.

Description of drawings

FIG. 1 is a schematic structural diagram of a vehicle-mounted intelligent charging device of the present invention.

FIG. 2 is a schematic structural diagram of the USB power supply protection circuit in FIG. 1 .

Among them, 1 SOC microprocessor, 2 USB power supply protection circuit, 201 voltage control interrupt port, 202 first voltage input port, 203 parallel resistor, 204 first triode, 205 first adjustable resistor, 206 second triode Tube, 207 voltage acquisition port, 208 ground wire, 209 second adjustable resistor, 210 third adjustable resistor, 211 fourth adjustable resistor, 212 second voltage input port, 3 USB ports, 4 speakers, 5 display screen.

detailed description

As shown in Figure 2, it is a USB power supply protection circuit, including a voltage control interrupt port 201, a first voltage input port 202 and a voltage acquisition port 207, the first voltage input port 202 is connected with a parallel resistor 203, and the output terminal of the parallel resistor 203 Connect the C collector of the first triode 204, the B base of the first triode 204 is connected to the second adjustable resistor 209, the second adjustable resistor 209 is connected to the voltage control interrupt port 201, the first triode 204 The E emitter is respectively connected to the first adjustable resistor 205 and the B base of the second triode 206, the first adjustable resistor 205 is connected to the ground wire 208, and the C collector of the second triode is respectively connected to the third adjustable resistor 210 and the fourth adjustable resistor 211, the third adjustable resistor 210 is connected to the voltage acquisition port 207, the fourth adjustable resistor 211 is connected to the second voltage input port 212, and the E emitter of the second triode is connected to the ground Line 208, the first voltage input port 202 is connected to the power supply, the voltage control interrupt port 201 is at a high level during normal operation, and outputs a 5V voltage to adjust the resistance value of the first adjustable resistor 205 to limit the size of the passing current. When the current passing through the first adjustable resistor 205 exceeds the limit value, and the voltage across the first adjustable resistor 205 exceeds 0.7V, the second triode 206 is turned on, and the voltage acquisition port 207 receives a low-level signal, If it is judged as overcurrent, the voltage control interrupt port 201 cuts off the USB power supply.

As shown in Figures 1-2, corresponding to the above-mentioned USB power supply protection circuit, the present invention also provides an on-vehicle intelligent charging device using the USB power supply protection circuit, including a SOC microprocessor 1 for mobile phone charging management, an SOC microprocessor The device 1 is connected with the display screen 5 of the USB interface 3 and peripherals, the SOC microprocessor 1 is also connected with the voltage control interrupt port 201 and the voltage acquisition port 207 of the USB power supply protection circuit 2, the USB interface 3 and the USB power supply protection circuit 2 The first voltage input port 202 is connected, furthermore, the SOC microprocessor 1 is also connected to the speaker 4 .

When working, first connect the mobile phone to the USB interface 3 for charging, the SOC microprocessor 1 sends the AT command to read the battery information to the mobile phone through the USB interface 3, and the mobile phone receives the AT command to feed back the battery information (battery status, battery power, power level, battery state of health, battery voltage and battery temperature, etc.), the battery information of the mobile phone is displayed on the display screen 5, and the SOC microprocessor 1 dynamically monitors the charging of the battery of the mobile phone according to the battery information, and the USB power supply protection circuit 2 simultaneously monitors the charging of the charging device. The voltage and current are monitored, and when the charging overcurrent, overvoltage or battery temperature is too high, the SOC microprocessor 1 cuts off the power supply.

The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solutions disclosed in the present invention, those skilled in the art can make some replacements and modifications to some of the technical features according to the disclosed technical content without creative work. Deformation, these replacements and deformations are all within the protection scope of the present invention.

Claims (6)

1.USB power supply protection circuit, it is characterised in that: include Control of Voltage interruptive port, the first voltage input end mouth and electricity Pressure gathers port, and described first voltage input end mouth connects parallel resistance, and the outfan of parallel resistance connects the first audion C colelctor electrode, the B base stage of the first audion connects Control of Voltage interruptive port, and the E emitter stage of the first audion connects the respectively The B base stage of one adjustable resistor and the second audion, the C colelctor electrode of the second audion is connected with voltage acquisition port, described The outfan of the first adjustable resistor and the E emitter stage of the second audion all connect ground wire.

USB power supply protection circuit the most according to claim 1, it is characterised in that: described Control of Voltage interruptive port and Connect between the B base stage of one audion and have the second adjustable resistor.

USB power supply protection circuit the most according to claim 1, it is characterised in that: described voltage acquisition port and the two or three Connect between the C colelctor electrode of pole pipe and have the 3rd adjustable resistor.

USB power supply protection circuit the most according to claim 1, it is characterised in that: the C colelctor electrode warp of described second audion 4th adjustable resistor connects the second voltage input end mouth.

5. use the vehicle intelligent charging device of USB power supply protection circuit as claimed in claim 1, it is characterised in that: include For the SOC microprocessor of mobile phone Charge Management, SOC microprocessor connects the display screen having USB interface and peripheral hardware, described SOC Microprocessor is also associated with Control of Voltage interruptive port and the voltage acquisition port of USB power supply protection circuit, described USB interface with First voltage input end mouth of USB power supply protection circuit is connected.

Vehicle intelligent charging device the most according to claim 5, it is characterised in that: described SOC microprocessor is also associated with Speaker.