An emergency battery protection and emergency indicator light circuit

Abstract

The present invention relates to an emergency battery protection and emergency indicator light circuit, comprising: a charging IC, a battery reverse connection protection circuit, a battery full charge detection circuit and a battery removal or fault detection circuit; when the battery is not reversed, the battery reverse connection circuit connects the BAT pin of the charging IC to the positive pole of the battery, and the battery is charged normally; when the battery is reversed, the battery reverse connection circuit disconnects the BAT pin of the charging IC from the positive pole of the battery, and the battery is not charged; when the battery is fully charged, the battery full charge detection circuit pulls the CHRG pin of the charging IC to a low level, and the indicator light connected to the cathode and the CHRG pin lights up; when the battery is removed, the battery removal or fault detection circuit disconnects the positive pole of the indicator light from the input power supply VIN, and the indicator light goes out. The above-mentioned emergency battery protection and emergency indicator light circuits meet the requirements of safety certification.

Description

Technical Field

[0001] The invention relates to a charging circuit, in particular to a battery protection and indicator light circuit. Background Art

[0002] The traditional emergency light indicator circuit lights up after charging, goes out when fully charged, and goes out when the battery fails. This makes it impossible to distinguish between the two states of full charge and failure, which does not meet the requirements of safety certification. Summary of the invention

[0003] The main technical problem to be solved by the present invention is to provide an emergency battery protection and emergency indicator light circuit that meets the requirements of safety certification.

[0004] In order to solve the above technical problems, the present invention provides an emergency battery protection and emergency indicator light circuit, including: a charging IC, a battery reverse connection protection circuit, a battery full charge detection circuit and a battery removal or fault detection circuit;

[0005] When the battery is not reversely connected, the battery reverse connection circuit connects the BAT pin of the charging IC to the positive electrode of the battery, and the battery is charged normally; when the battery is reversely connected, the battery reverse connection circuit disconnects the BAT pin of the charging IC from the positive electrode of the battery, and the battery is not charged;

[0006] When the battery is fully charged, the battery full charge detection circuit pulls the CHRG pin of the charging IC to a low level, and the indicator light connected to the cathode and the CHRG pin lights up;

[0007] When the battery is pulled out, the battery pull-out or fault detection circuit disconnects the positive pole of the indicator light from the input power supply VIN, and the indicator light goes out.

[0008] In a preferred embodiment: the battery full charge detection circuit includes a pMOS tube Q4 and a transistor Q5, Q4 is connected between the BAT terminal and the BAT+ terminal of the charging IC; the transistor Q5 is used to control Q4 to be turned on or off.

[0009] In a preferred embodiment: the source of Q4 is connected to the BAT terminal of the charging IC, and the drain is connected to the BAT+ terminal; the gate of Q5 is connected to the BAT+ terminal through a resistor R6, the emitter is grounded, and the collector is connected to the BAT terminal of the charging IC through a resistor R8.

[0010] In a preferred embodiment: the battery removal or fault detection circuit includes transistors Q1 and Q2;

[0011] The base of Q2 is connected to the BAT+ terminal through resistor R3, the emitter is grounded, and the collector is connected to the input power supply VIN through resistors R1 and R2; the emitter of Q1 is connected to the input power supply VIN, the base is connected to the same-named terminals of resistors R1 and R2, and the collector is connected to the positive terminal of the indicator light through resistor R5;

[0012] In addition, the BAT+ and BAT- terminals are respectively connected to a metal spring. When the battery is not unplugged, the two metal springs are ejected; when the battery is unplugged, the two metal springs are short-circuited.

[0013] In a preferred embodiment: the battery full charge detection circuit includes a three-terminal voltage regulator Q3, resistors R9 and R10;

[0014] The resistors R9 and R10 are connected in series between the BAT+ terminal and the BAT- terminal, the cathode of Q3 is connected to the CHRG pin of the charging IC, the anode is grounded, and the third terminal is connected to the same-named terminals of the resistors R9 and R10.

[0015] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0016] The present invention provides an emergency battery protection and emergency indicator light circuit, which has the characteristics of fast response speed, low cost, high reliability, etc. The circuit includes a battery positive and reverse connection protection circuit, a battery charging and full charge detection circuit, and a battery removal or fault detection circuit. Through the combination of the above circuits, the positive and reverse polarity protection of the rechargeable battery can be realized, the indicator light is on during charging, the indicator light is on after full charging, and the indicator light goes out after the battery is removed or the battery fails, which meets the safety certification requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 4 is a circuit diagram of a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] refer to Figure 1 , an emergency battery protection and emergency indicator light circuit, comprising: a charging IC, a battery reverse connection protection circuit, a battery full charge detection circuit and a battery removal or fault detection circuit;

[0022] When the battery is not reversely connected, the battery reverse connection circuit connects the BAT pin of the charging IC to the positive electrode of the battery, and the battery is charged normally; when the battery is reversely connected, the battery reverse connection circuit disconnects the BAT pin of the charging IC from the positive electrode of the battery, and the battery is not charged;

[0023] When the battery is fully charged, the battery full charge detection circuit pulls the CHRG pin of the charging IC to a low level, and the indicator light connected to the cathode and the CHRG pin lights up;

[0024] When the battery is pulled out, the battery pull-out or fault detection circuit disconnects the positive pole of the indicator light from the input power supply VIN, and the indicator light goes out.

[0025] The above-mentioned emergency battery protection and emergency indicator light circuit can realize the positive and reverse polarity protection of the rechargeable battery through the combination of the above-mentioned circuit parts. The indicator light is on during charging, the indicator light is on after full charging, and the indicator light goes out after the battery is unplugged or the battery fails to meet the safety certification requirements.

[0026] In this embodiment, the battery full charge detection circuit includes a pMOS tube Q4 and a transistor Q5, Q4 is connected between the BAT terminal and the BAT+ terminal of the charging IC; the transistor Q5 is used to control Q4 to be turned on or off.

[0027] Specifically, the source of Q4 is connected to the BAT terminal of the charging IC, and the drain is connected to the BAT+ terminal; the gate of Q5 is connected to the BAT+ terminal through a resistor R6, the emitter is grounded, and the collector is connected to the BAT terminal of the charging IC through a resistor R8.

[0028] When the positive and negative connections of the battery are correct, the resistor R6 terminal is energized, so Q5 Vbe is energized and Q5 is turned on. After Q5 is turned on, the gate voltage of PMOS Q4 is zero, so Q4 Vgs < 0, Q4 is turned on. After Q4 is turned on, the BAT terminal of the charging IC U1 charges the battery normally. When the positive and negative connections of the battery are incorrect, Q5 is not turned on, so PMOS Q4 Vgs> 0, Q4 is not turned on, and the battery is not charged. In this way, the battery and the circuit are effectively protected.

[0029] In this embodiment, the battery removal or fault detection circuit includes a transistor Q1 and a transistor Q2;

[0030] The base of Q2 is connected to the BAT+ terminal through a resistor R3, the emitter is grounded, and the collector is connected to the input power supply VIN through resistors R1 and R2; the emitter of Q1 is connected to the input power supply VIN, the base is connected to the same-named terminals of resistors R1 and R2, and the collector is connected to the positive electrode of the indicator light through a resistor R5; and a metal spring is connected to the BAT+ and BAT- terminals respectively, and when the battery is not unplugged, the two metal springs pop open; when the battery is unplugged, the two metal springs are short-circuited.

[0031] When the battery is connected to the circuit, the metal spring at the terminal pops open and the circuit performs normal charging and discharging operations. When the battery is unplugged, the metal spring at the terminal closes, and the BAT+BAT- ends are short-circuited, so that the voltage at the R6 terminal is 0V, Q5 is not conducting, and thus Q4 is not conducting; at this time, the voltage at the R3 terminal is also 0V, Q2 is not conducting, and thus Q1 is not conducting, and the indicator light goes out, meeting the certification requirements.

[0032] The battery full charge detection circuit in this embodiment includes a three-terminal voltage regulator Q3, resistors R9 and R10; the resistors R9 and R10 are connected in series between the BAT+ terminal and the BAT- terminal, the cathode of Q3 is connected to the CHRG pin of the charging IC, the anode is grounded, and the third terminal is connected to the same-named terminals of the resistors R9 and R10.

[0033] When the positive and negative connections of the battery are correct and the battery is charged normally, the CHRG pin of the charging IC U1 is low level, and the R3 terminal is high level, causing Q2 to turn on. After Q2 turns on, the PNP transistor Q1 turns on, and the indicator light is on; when the battery is fully charged, the CHRG pin of the traditional charging IC U1 on the market is in a high impedance state, and the indicator light is off, which does not meet the certification requirements. Through the above circuit modification, when the battery is fully charged, the voltage will increase. Through the voltage divider setting of R9 and R10, the R terminal voltage of the three-terminal voltage regulator TL431 reaches 2.5V. At this time, the Q3 KA terminal is turned on, thereby pulling the CHRG pin low, and the indicator light is normally on, thus meeting the certification requirements.

[0034] The above is only a preferred specific implementation of the present invention; however, the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solution and its improved conception within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. An emergency battery protection and emergency indicator light circuit, characterized in that include: Charging IC, battery reverse connection protection circuit, battery full charge detection circuit and battery removal or fault detection circuit; When the battery is not reversely connected, the battery reverse connection protection circuit connects the BAT pin of the charging IC to the BAT+ of the battery, and the battery is charged normally; when the battery is reversely connected, the battery reverse connection protection circuit disconnects the BAT pin of the charging IC from the BAT+ of the battery, and the battery is not charged; When the battery is fully charged, the battery full charge detection circuit pulls the CHRG pin of the charging IC to a low level, and the indicator light connected to the cathode and the CHRG pin lights up; When the battery is unplugged, the battery unplugging or fault detection circuit disconnects the positive pole of the indicator light from the input power supply VIN, and the indicator light goes out; the battery full charge detection circuit includes a pMOS tube Q4 and a transistor Q5, Q4 is connected between the BAT terminal and the BAT+ terminal of the charging IC; the transistor Q5 is used to control Q4 to be turned on or off; the source of Q4 is connected to the BAT terminal of the charging IC, and the drain is connected to the BAT+ terminal; the gate of Q5 is connected to the BAT+ terminal through a resistor R6, the emitter is grounded, and the collector is connected to the BAT terminal of the charging IC through a resistor R8; the battery unplugging or fault detection circuit includes transistors Q1 and Q2; The base of Q2 is connected to the BAT+ terminal through resistor R3, the emitter is grounded, and the collector is connected to the input power supply VIN through resistors R1 and R2; the emitter of Q1 is connected to the input power supply VIN, the base is connected to the same-named terminals of resistors R1 and R2, and the collector is connected to the positive terminal of the indicator light through resistor R5; In addition, the BAT+ terminal and the BAT- terminal are respectively connected to a metal spring, and when the battery is not pulled out, the two metal springs are ejected; when the battery is pulled out, the two metal springs are short-circuited; the battery full charge detection circuit includes a three-terminal voltage regulator Q3, resistors R9, R10; The resistors R9 and R10 are connected in series between the BAT+ terminal and the BAT- terminal, the cathode of Q3 is connected to the CHRG pin of the charging IC, the anode is grounded, and the third terminal is connected to one end of the resistors R9 and R10 connected to each other.

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