CN217183011U

CN217183011U - Multifunctional boosting circuit

Info

Publication number: CN217183011U
Application number: CN202220761979.4U
Authority: CN
Inventors: 沈钰皓; 张益波; 沈盛瀚
Original assignee: Zhejiang Sci Tech University ZSTU
Current assignee: Zhejiang Sci Tech University ZSTU
Priority date: 2022-04-02
Filing date: 2022-04-02
Publication date: 2022-08-12
Anticipated expiration: 2032-04-02

Abstract

The utility model provides a multi-functional boost circuit, relate to boost circuit technical field, multi-functional boost circuit is by preventing reverse connection circuit, overvoltage crowbar, boost circuit, isolating circuit and prevent overcharging the circuit and constitute, boost circuit adopts LM2735X chip, insert boost chip U2's VIN foot after electric capacity C6 and resistance R6 establish ties, insert the EN foot after electric capacity C6 and resistance R6 are parallelly connected, GND foot ground, resistance R7 and electric capacity C8 establish ties again with electric capacity C7, resistance R8 parallelly connected FB foot, resistance R7, electric capacity C8 and electric capacity C6 ground connection, electric capacity C6 and resistance R6 insert the SW foot through inductance L1 after parallelly connected, stabilivolt D2's positive pole connects inductance L1, negative pole resistance R8, NMOS pipe Q3 source ground connection, the drain electrode connects the effect that plays isolation protection circuit behind transformer T1. The utility model discloses safe and reliable, convenient, the practicality of charging is strong, uses the lithium cell to give the equipment of higher charging voltage demands such as notebook computer when being applicable to the open air.

Description

Multifunctional boosting circuit

Technical Field

The utility model relates to a boost circuit technical field especially relates to a multi-functional boost circuit.

Background

The booster circuit is needed in many occasions, people often find that the electric quantity of electronic equipment carried by people is insufficient when going out, the burden of partial equipped charging equipment is heavy when going out, even if charging equipment accessories are brought, proper charging interfaces do not exist, even if charging interfaces exist, the charging equipment cannot walk around with a product, and the booster circuit has great limitation; moreover, some charging devices have specificity and cannot be applied to multiple devices; in addition, some electronic devices should stop charging after charging is saturated, otherwise damage to the interior of the device may occur, but some charging devices cannot meet the requirement.

Therefore, a multifunctional boost circuit is needed to solve the above technical problems.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides a multifunctional booster circuit for the realization can hand-carry, can be used to the equipment of different charging voltage demands, automatic shutdown after the saturation of charging charges.

In order to achieve the above object, the utility model provides a following technical scheme:

a multifunctional booster circuit comprises a power supply circuit, an anti-reverse connection circuit, an overvoltage protection circuit, a booster circuit, an isolation circuit and an anti-overcharge circuit which are electrically connected in sequence, wherein the booster circuit consists of a capacitor C6, a capacitor C7, a capacitor C8, a resistor R6, a resistor R7, a resistor R8, an inductor L1, a voltage regulator tube D2 and a booster chip U2, an EN pin of a booster chip U2 is grounded after being connected in series through a resistor R6 and a capacitor C6, a VIN pin of the chip U2 is grounded after being connected in series through a capacitor C6, a SW pin of the booster chip U2 is grounded after being connected in series through a voltage regulator tube D2 and a capacitor C8, a GND pin of the booster chip U2 is grounded, an FB pin of the booster chip U2 is grounded after being connected in series through a resistor R7, the inductor L1 is connected in parallel to two ends of a VIN and pins of the booster chip U2, and the resistor SW 2 and the capacitor C2 are connected in parallel.

In a preferred embodiment, the power circuit is formed by connecting 3 lithium batteries in series, and the output voltage of the power circuit is 3.7-4.2V.

As a preferred embodiment, the overvoltage protection circuit comprises a PMOS transistor, a resistor R, a capacitor C, an overvoltage protection circuit chip U, an NMOS transistor Q, and a fuse F, wherein a source of the PMOS transistor, a positive terminal of a power supply B, and a positive terminal of the power supply B are respectively connected to V, and V pins of the overvoltage protection circuit chip U through the resistor R, and the resistor R, the capacitor C, and the capacitor C are respectively connected in parallel to two ends of V and V pins, V and PAD pins, the PMOS and PAD pins of the overvoltage protection circuit chip U, the resistor R is connected in parallel to two ends of VDD pin of the overvoltage protection circuit chip U and a source of the NMOS transistor, a gate of the NMOS transistor enters an OUT pin of the overvoltage protection circuit chip U, and the fuse F is connected to two ends of a drain of the NMOS transistor Q and the resistor R, the VSS pin of the overvoltage protection circuit chip U1 is connected with the negative electrode of a power supply B3, and the overvoltage protection circuit chip U1 adopts a BQ294512 chip.

As a preferred embodiment, the isolation circuit is composed of an NMOS transistor Q3, a transformer T1, a diode D3, and an electrolytic capacitor C9, the source of the NMOS transistor Q3 is grounded, the drain of the NMOS transistor Q3 is connected to the 2 port of the transformer T1, and the 4 port of the transformer T1 is connected to the 3 port of the transformer T1 through the diode D3 and the electrolytic capacitor C9 in series.

As a preferred embodiment, the anti-overcharge circuit includes a resistor R9, a resistor R10, a resistor R11, a resistor R12, a variable resistor RP 12, an LED 12, an electrolytic capacitor C12, a transistor Q12, and a transistor Q12, wherein the resistor R12 is connected in series with the LED 12, the variable resistor RP 12 is connected in series with the resistor R12, a port is connected to the resistor R12 and the variable resistor RP 12, a base of the transistor Q12 is connected to a variable terminal of the variable resistor RP 12, an emitter of the transistor Q12 is connected to port 2 after passing through the resistor R12, a collector of the transistor Q12 is connected to a base of the transistor Q12, a collector of the transistor Q12 is connected to port 2, an emitter of the transistor R12 is connected to a negative terminal of the LED 12 through the resistor R12, an electrolytic capacitor C12, a positive electrode of the base of the transistor Q12 is connected to the negative electrode 12, and a positive electrode of the transistor Q12 is connected to the transistor 12.

As a preferred embodiment, the anti-reverse-connection circuit is composed of a capacitor C1, a voltage regulator tube D1, a resistor R1 and a PMOS tube Q1, wherein the capacitor C1 is connected with a power input end, the capacitor C1 is connected with the voltage regulator tube D1 in parallel and then connected with a drain electrode of the PMOS tube Q1, the resistor R1 is connected with a gate electrode of the PMOS tube, and a negative electrode of the voltage regulator tube D1 is connected with the resistor R1.

Compared with the prior art, the utility model has the advantages and positive effects that,

the utility model provides a multi-functional boost circuit for the realization can hand-carry, can be used to the equipment of different charging voltage demands, automatic shutdown after the saturation of charging charges, safe and reliable, it is convenient, the practicality is strong to charge, uses the lithium cell to give the equipment of higher charging voltage demands such as notebook computer when being applicable to the open air.

Drawings

Fig. 1 is a circuit diagram of a medium power circuit, an anti-reverse connection circuit, an overvoltage protection circuit and a booster circuit of the present invention;

fig. 2 is a circuit diagram of the middle isolation circuit and the overcharge prevention circuit of the present invention.

Detailed Description

The following describes the present invention with reference to the accompanying drawings. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features related to the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Example (b):

referring to fig. 1-2, the present invention provides a technical solution: a multifunctional booster circuit comprises a power supply circuit, an anti-reverse connection circuit, an overvoltage protection circuit, a booster circuit, an isolation circuit and an anti-overcharge circuit which are electrically connected in sequence, wherein the booster circuit is composed of a capacitor C6, a capacitor C7, a capacitor C8, a resistor R6, a resistor R7, a resistor R8, an inductor L1, a voltage regulator tube D2 and a booster chip U2, an EN pin of a booster chip U2 is grounded after being connected in series through a resistor R6 and a capacitor C6, a VIN pin of the chip U2 is grounded after being connected in series through a capacitor C6, a SW pin of the booster chip U2 is grounded after being connected in series through a voltage regulator tube D2 and a capacitor C8, a GND pin of the booster chip U2 is grounded, an FB pin of the booster chip U2 is grounded after being connected in series through a resistor R7, the inductor L1 is connected in parallel to two ends of a VIN and a SW pin of the booster chip U2, and the SW pin of the booster chip U2 are connected in parallel with the capacitor C2 and the resistor R2 after being connected in series.

In this embodiment, the boost chip U2 employs an LM2735 chip, which provides a stable output voltage by switching an internal NMOS control switch at a constant frequency and a variable duty cycle, and also protects the internal NMOS switch using cycle-by-cycle current limitation, and a resistor R7 and a capacitor C8 are connected in series and then connected in parallel with a capacitor C7 and a resistor R8, where R7 is a bottom resistor and R8 is a resistor connected to the output voltage, and their ratio can be changed to set the output voltage, so that the converter will have good transient response due to the existence of internal compensation, and provide sufficient phase margin for all input and output voltage combinations.

Furthermore, the power circuit is formed by connecting 3 lithium batteries in series, and the output voltage of the power circuit is 3.7-4.2V.

In this embodiment, 3 lithium batteries can provide an input voltage of about 11.1-12.6V.

Further, the overvoltage protection circuit is composed of a PMOS tube, a resistor R, a capacitor C, an overvoltage protection circuit chip U, an NMOS tube Q and a fuse F, a source electrode of the PMOS tube, an anode of a power supply B and an anode of the power supply B are respectively connected with V pins, V pins and V pins of the overvoltage protection circuit chip U through the resistor R, the resistor R and the resistor R, the capacitor C and the capacitor C are respectively connected in parallel at two ends of the V pins, the PAD pins, the VDD pins and the PAD pins of the overvoltage protection circuit chip U, the resistor R is connected in parallel at two ends of the VDD pin of the overvoltage protection circuit chip U and the source electrode of the PMOS tube, a grid electrode of the NMOS tube enters an OUT pin of the overvoltage protection circuit chip U, the fuse F is connected at two ends of a drain electrode of the NMOS tube Q and the resistor R, the VSS pin of the overvoltage protection circuit chip U is connected with a negative electrode of the power supply B, the overvoltage protection circuit chip U1 adopts a BQ294512 chip.

In this embodiment, the overvoltage protection circuit chip U1 adopts a BQ294512 chip, and can be used as a secondary voltage monitor and protector of a lithium battery system, and the source of the PMOS transistor, the positive electrode of the power supply B2 and the positive electrode of the power supply B3 are connected to pins V3, V2 and V1 of the overvoltage protection circuit chip U1 through a resistor R2, a resistor R3 and a resistor R4, respectively, so that whether each battery has an overvoltage state can be independently monitored by comparing the actual battery voltage with a protection voltage threshold VOV, according to the configuration, if any battery of the three batteries is in an overvoltage state, an output is triggered after a fixed delay, and after the overvoltage state meets a specified delay timer condition, the output is triggered to a high level state, and the capacitor C2, the capacitor C3, the capacitor C4 and the capacitor C5 are respectively connected in parallel to pins V3 and V2, V2 and V1 of the overvoltage protection circuit chip U1, and the pins V1, Across V1 and the PAD pin, VDD and PAD pins, each input requires a series resistor and a capacitor for noise filtering and stable voltage monitoring, and if any battery voltage exceeds the over-voltage threshold within the configured delay time, the OUT pin will pull high internally, shorting the fuse to ground, to blow the fuse and cut the power path using the battery or charger power, and when all battery voltages are below the over-voltage threshold, the circuit returns to normal mode.

Furthermore, the isolation circuit is composed of an NMOS tube Q3, a transformer T1, a diode D3 and an electrolytic capacitor C9, the source of the NMOS tube Q3 is grounded, the drain of the NMOS tube Q3 is connected with the 2 port of the transformer T1, and the 4 port of the transformer T1 is connected with the 3 port of the transformer T1 after being connected in series through the diode D3 and the electrolytic capacitor C9.

In this embodiment, the transformer T1 uses a transformer of the flyback converter to store energy, stores energy when the NMOS is turned on, and releases energy when the NMOS is turned off, so that the NMOS is always in a balanced state and cannot reach saturation, and in addition, the voltage can be reduced or increased by using the duty ratio and the turn ratio; the simplest isolated topology is adopted, so that the cost is low.

Further, the anti-overcharge circuit is composed of a resistor R9, a resistor R10, a resistor R11, a resistor R12, a variable resistor RP 12, an LED 12, an electrolytic capacitor C12, a triode Q12 and a triode Q12, wherein the resistor R12 is connected in series with the LED 12, the variable resistor RP 12 is connected in series with the resistor R12, a port is connected with the resistor R12 and the variable resistor RP 12, a base of the triode Q12 is connected with a variable port of the variable resistor RP 12, an emitter of the triode Q12 is connected with a port 2 through the resistor R12, a collector of the triode Q12 is connected with a base of the triode Q12, a collector of the triode Q12 is connected with the port 2, an emitter of the triode is connected with a negative pole of the LED 12, a negative pole of the electrolytic capacitor C12, a resistor R12 and a negative pole of the triode Q12, a collector of the electrolytic capacitor C12 is connected with a base of the triode Q12.

In this embodiment, the adjusting resistor R12 can adjust the charging current, the adjusting variable resistor RP1 can adjust the charging voltage, the LED1 is a power indicator, the LED2 is a charging indicator, and when the device is charged to saturation, the charging is automatically stopped and the LED2 is turned off.

Furthermore, the anti-reverse-connection circuit is composed of a capacitor C1, a voltage regulator tube D1, a resistor R1 and a PMOS tube Q1, wherein the capacitor C1 is connected with the input end of a power supply, the capacitor C1 is connected with the voltage regulator tube D1 in parallel and then connected to the drain electrode of the PMOS tube Q1, the resistor R1 is connected to the grid electrode of the PMOS tube, and the negative electrode of the voltage regulator tube D1 is connected with the resistor R1.

In this embodiment, the capacitor C1 is connected to the power input terminal, and has the functions of soft start and ripple filtering, and the capacitor C1 is connected in parallel with the voltage regulator D1 and then connected to the drain of the PMOS transistor Q1, wherein the voltage regulator is used for protecting the PMOS transistor Q1 and preventing breakdown.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in other forms, and any person skilled in the art may use the above-mentioned technical contents to change or modify the equivalent embodiment into equivalent changes and apply to other fields, but any simple modification, equivalent change and modification made to the above embodiments according to the technical matters of the present invention will still fall within the protection scope of the technical solution of the present invention.

Claims

1. A multifunctional booster circuit is characterized by comprising a power supply circuit, an anti-reverse-connection circuit, an overvoltage protection circuit, a booster circuit, an isolation circuit and an anti-overcharging circuit which are sequentially and electrically connected, wherein the booster circuit is composed of a capacitor C6, a capacitor C7, a capacitor C8, a resistor R6, a resistor R7, a resistor R8, an inductor L1, a voltage regulator tube D2 and a booster chip U2, an EN pin of a booster chip U2 is grounded after being connected in series through a resistor R6 and a capacitor C6, a VIN pin of the chip U2 is grounded after passing through a capacitor C6, an SW pin of the booster chip U2 is grounded after being connected in series through a voltage regulator tube D2 and a capacitor C8, a GND pin of the booster chip U2 is grounded, a GND pin of the booster chip U2 is grounded after passing through a resistor R7, the inductor L1 is connected in parallel with two ends of an SW pin and a leg of the booster chip U2, the resistor R2 and the capacitor C2 are connected in series and the resistor 2 and the resistor C2 are connected in parallel.

2. The multi-functional boost circuit of claim 1, wherein: the power circuit is formed by connecting 3 lithium batteries in series, and the output voltage of the power circuit is 3.7-4.2V.

3. The multi-functional boost circuit of claim 1, wherein: the overvoltage protection circuit comprises a PMOS tube, a resistor R2, a resistor R3, a resistor R4, a resistor R5, a capacitor C2, a capacitor C3, a capacitor C4, a capacitor C5, an overvoltage protection circuit chip U1, an NMOS tube Q2 and a fuse F1, wherein the source electrode of the PMOS tube, the positive electrode of a power supply B2 and the positive electrode of the power supply B3 are respectively connected with the pins V3, V2 and V1 of the overvoltage protection circuit chip U1 through a resistor R2, a resistor R3 and a resistor R4, the capacitor C2, the capacitor C3, the capacitor C4 and the capacitor C5 are respectively connected in parallel with the pins V5 and V5 of the overvoltage protection circuit chip U5, the pins V5 and PAD, the two ends of the pins and the pins of the PMOS tube, the PMOS tube OUT 4 and the negative electrode of the NMOS tube of the overvoltage protection circuit chip U5 are connected with the grid electrode of the overvoltage protection circuit chip OUT, the NMOS 5, the overvoltage protection circuit chip U1 adopts a BQ294512 chip.

4. The multi-functional boost circuit of claim 1, wherein: the isolation circuit is composed of an NMOS tube Q3, a transformer T1, a diode D3 and an electrolytic capacitor C9, wherein the source electrode of the NMOS tube Q3 is grounded, the drain electrode of the NMOS tube Q3 is connected with a 2-port of the transformer T1, and a 4-port of the transformer T1 is connected with a 3-port of the transformer T1 after being connected in series through the diode D3 and the electrolytic capacitor C9.

5. The multi-functional boost circuit of claim 1, wherein: the anti-overcharging circuit comprises a resistor R9, a resistor R10, a resistor R11, a resistor R12, a variable resistor RP 12, an LED 12, an electrolytic capacitor C12, a triode Q12 and a triode Q12, wherein the resistor R12 is connected with the LED 12 in series, the variable resistor RP 12 is connected with the resistor R12 in series, a port is connected with the resistor R12 and the variable resistor RP 12, the base of the triode Q12 is connected with the variable end of the variable resistor RP 12, the emitter of the triode Q12 is connected with a port 2 through the resistor R12, the collector of the triode Q12 is connected with the base of the triode Q12, the collector of the triode Q12 is connected with the port 2, the emitter of the triode Q12 is connected with the cathode of the LED 12, the cathode of the electrolytic capacitor C12, the resistor R12 and the cathode of the triode Q12, and the collector of the triode Q12 are connected with the base of the triode Q12.

6. The multi-functional boost circuit of claim 1, wherein: the anti-reverse-connection circuit is composed of a capacitor C1, a voltage regulator tube D1, a resistor R1 and a PMOS tube Q1, wherein the capacitor C1 is connected with the input end of a power supply, the capacitor C1 is connected with the voltage regulator tube D1 in parallel and then connected with the drain electrode of the PMOS tube Q1, the resistor R1 is connected with the grid electrode of the PMOS tube, and the negative electrode of the voltage regulator tube D1 is connected with the resistor R1.