CN211456722U

CN211456722U - Multi-stage protection charger charging auxiliary circuit

Info

Publication number: CN211456722U
Application number: CN201922345200.1U
Authority: CN
Inventors: 黄少成
Original assignee: Dongguan Fuyuan Electronic Co ltd
Current assignee: Dongguan Fuyuan Electronic Co ltd
Priority date: 2019-12-23
Filing date: 2019-12-23
Publication date: 2020-09-08
Anticipated expiration: 2029-12-23

Abstract

The utility model discloses a charger charging auxiliary circuit of multistage protection, it includes power output V + end, power output V-end, load interface and MOS pipe switch unit and starting circuit unit and be used for controlling this MOS pipe switch unit and end and out of work and the fourth resistance that connects gradually, fourth diode and full-rotating lamp signal input part, full-rotating lamp signal input part is connected with full-rotating lamp signal output part in the charger, this load interface has V + end and on-off control end, be connected with between V + end and the on-off control end and prevent reverse protection circuit; the reverse connection prevention protection circuit comprises a photoelectric coupler, a first pin of the photoelectric coupler is connected with a switch control end, a second pin is connected with a V + end after being connected with an anode of a first diode, a delay capacitor is connected between a third pin and a fourth pin, the fourth pin is connected with a voltage-dividing large resistor and then is connected with a power output V + end, the third pin is connected with a b pole of a third triode, and an e pole and a c pole of the third triode are respectively connected with a power output V-end and an MOS tube switch unit.

Description

Multi-stage protection charger charging auxiliary circuit

The technical field is as follows:

the utility model relates to a charger technical field refers in particular to a charger auxiliary circuit that charges of multistage protection.

Background art:

a charger is a device for charging various electronic products, is widely used, and becomes an essential component of the electronic products.

When the existing charger is connected with a battery terminal reversely, an internal circuit and a battery of the charger are easy to burn, and safety accidents are easy to happen. Meanwhile, the charger cannot implement a hundred percent turn-off circuit to control not to charge the battery when fully charged.

In view of the above, the present inventors propose the following.

The utility model has the following contents:

an object of the utility model is to overcome prior art's not enough, provide a charger auxiliary circuit that charges of multistage protection.

In order to solve the technical problem, the utility model discloses a following technical scheme: the charging auxiliary circuit of the multi-stage protection charger comprises a power output V + end, a power output V-end, a load interface, an MOS tube switch unit and a starting circuit unit, wherein the power output V + end and the power output V-end are connected with the positive pole and the negative pole of a charger output interface, the load interface, the MOS tube switch unit and the starting circuit unit are connected between the power output V + end and the power output V-end, the load interface is provided with a V + end and a switch control end which are respectively used for being connected with the positive pole and the negative pole of a battery load, the V + end is connected with the power output V + end, the switch control end is connected with the MOS tube switch unit, an anti-reverse connection protection circuit is connected between the V + end and the switch control end and comprises an optoelectronic coupler, a first pin of the optoelectronic coupler is connected with the switch control end, a second pin of the optoelectronic coupler is connected with the anode of a first diode, the cathode of the first diode is connected with the V +, the fourth pin of the photoelectric coupler is also connected with a voltage-dividing large resistor and then connected with a power output V + end, the third pin of the photoelectric coupler is connected with the b pole of a third triode, the e pole of the third triode is connected with a power output V-end, and the c pole of the third triode is connected with the MOS tube switch unit and the starting circuit unit; the charger charging auxiliary circuit also comprises a fourth resistor, a fourth diode and a full-charge turning signal input end, wherein the fourth resistor, the fourth diode and the full-charge turning signal input end are used for controlling the MOS tube switching unit to stop working and are sequentially connected, the cathode of the fourth diode is connected with the fourth resistor, the anode of the fourth diode is connected with the full-charge turning signal input end, and the full-charge turning signal input end is connected with the full-charge turning signal output end in the charger.

Further, in the technical scheme, the type of the photoelectric coupler is LTV-357T-C; the model of the third triode is SS 8050.

Further, in the above technical solution, a voltage dividing resistor R9 is further connected between the cathode of the first diode and the V + terminal, and a resistance value of the resistor R9 is 5.6k Ω.

Furthermore, in the above technical solution, the starting circuit unit includes a first triode, a second triode for controlling conduction of the first triode, and a first capacitor connected between an e pole and a b pole of the first triode and having a charging delay function, the e pole of the first triode is connected to the V + end of the power output, the c pole of the first triode is connected to the MOS transistor switch unit, the b pole of the second triode is connected to the switch control end, the c pole of the second triode is connected to the b pole of the first triode, and the e pole of the second triode is connected to the V-end of the power output.

Further, in the above technical solution, the MOS switch unit includes a first MOS and a second MOS, a G pole of the first MOS is connected to a c pole of the third triode, the G pole of the first MOS is further connected to a resistor R7 and then connected to a G pole of the second MOS, a D pole of the second MOS is connected to the switch control terminal, an S pole of the first MOS is connected to an S pole of the second MOS, and the D pole of the second MOS is connected to the power output V-terminal; and the fourth resistor is connected with the G pole of the first MOS tube and the c pole of the first triode.

Further, in the above technical solution, a resistor R6 is further connected between the b-pole of the second triode and the switch control end, and a resistor R4 is further connected between the c-pole of the second triode and the b-pole of the first triode.

Further, in the above technical solution, the S pole and the G pole of the second MOS transistor are further connected to a second capacitor having a charging delay function; the G pole of the first MOS tube and the V-end of the power output are also connected with a voltage stabilizing diode.

Further, in the above technical solution, two ends of the first capacitor are further connected in parallel with a resistor R3; and a resistor R12 is also connected in parallel at two ends of the second capacitor.

Further, in the above technical solution, a resistor R11, a resistor R5, and a resistor R2 are further connected between the G-pole of the first MOS transistor and the c-pole of the first transistor.

Further, in the above technical solution, the model of the first triode is MMBT 5401; the model of the second triode is MMBT 5551; the model of the first MOS tube is NCE 1540K; the model of the second MOS tube is NCE 1540K.

After the technical scheme is adopted, compared with the prior art, the utility model has following beneficial effect: when the utility model is used, the power output V + end and the power output V-end are respectively connected with the positive electrode and the negative electrode of the charger output interface to be electrified, so that the load interface of the utility model is equivalent to the charger output interface and is used for connecting a load battery; when the charger is connected with the mains supply and electrified, and the V + end and the switch control end of the load interface are connected with the positive electrode and the negative electrode of the battery load, the reverse connection prevention protection circuit cannot work, and the starting circuit unit works to control the conduction of the MOS tube switch unit so as to realize the normal charging of the load battery; when load interface's on-off control end and V + end are connected with the positive negative pole of battery load, when connecting promptly reversely, battery load positive pole is by the on-off control end through optoelectronic coupler, first diode, divider resistance R9, the battery load negative pole is connected to the V + end, form the return circuit, switch on because of optoelectronic coupler, the charger positive voltage is through the divider resistance, optoelectronic coupler, provide forward bias for the third triode, this third triode switches on, to MOS pipe switch unit control voltage short circuit, MOS pipe switch unit closes, reach and prevent the purpose of anti-reverse connection and not burning circuit and charger circuit board, and guarantee product life, make the charger use safelyr, the order the utility model discloses extremely strong market competition has. Furthermore, when the charger charges the battery load, the charging current is larger than the lamp-turning current value, the lamp-turning signal is input with high potential, a high level is provided for the G pole of the MOS tube switch unit after passing through the fourth diode and the fourth resistor, the MOS tube switch unit is maintained to be conducted, the charging current is reduced along with the rise of the battery voltage, when the charging current is smaller than the lamp-turning current value, the lamp-turning signal is converted from the high level to the low level, the fourth diode 82 is cut off, the battery voltage is approximately equal to the charger voltage, the battery is fully charged, the voltages on the B pole and the E pole of the second triode 52 are approximately equal to 0V, therefore, the starting circuit unit 5 which is conducted cannot be conducted, the MOS tube switch unit is cut off and does not work, at the moment, the V-end of the power output is disconnected with the battery load, so that the charger cannot charge the battery load any more, a hundred percent turn-, and the loss is reduced. Additionally, the utility model discloses be applied to a little PCB board, with charger independent design, additionally add little PCB board on the charger promptly, make the charger have prevent reverse-connection protect function and fill the function that fully turn-offs and stop charging, realize multistage safeguard function to the work of supplementary charger charging is applicable to various chargers.

Description of the drawings:

fig. 1 is a circuit diagram of the present invention.

The specific implementation mode is as follows:

the present invention will be further described with reference to the following specific embodiments and accompanying drawings.

As shown in fig. 1, the charging auxiliary circuit of the charger with multi-stage protection comprises a power output V + terminal 1 and a power output V-terminal 2 connected with the positive and negative electrodes of the charger output interface, a load interface 3 connected between the power output V + terminal 1 and the power output V-terminal 2, a MOS transistor switch unit 4 and a start circuit unit 5, wherein the load interface 3 has a V + terminal 31 and a switch control terminal 32 respectively connected with the positive and negative electrodes of a battery load 6, the V + terminal 31 is connected with the power output V + terminal 1, the switch control terminal 32 is connected with the MOS transistor switch unit 4, an anti-reverse-connection protection circuit 7 is connected between the V + terminal 31 and the switch control terminal 32, the anti-reverse-connection protection circuit 7 comprises a photoelectric coupler 71, a first pin of the photoelectric coupler 71 is connected with the switch control terminal 32, a second pin of the photoelectric coupler 71 is connected with the anode of a first diode 72, the cathode of the first diode 72 is connected to the V + terminal 31, a delay capacitor 711 is connected between the third pin and the fourth pin of the photoelectric coupler 71, the fourth pin of the photoelectric coupler 71 is further connected to the voltage dividing resistor 712 and then connected to the power output V + terminal 1, the third pin of the photoelectric coupler 71 is connected to the b-pole of the third triode 73, the e-pole of the third triode 73 is connected to the power output V-terminal 2, and the c-pole of the third triode 73 is connected to the MOS transistor switch unit 4 and the start circuit unit 5. The charger charging auxiliary circuit further comprises a fourth resistor 81, a fourth diode 82 and a full-turning signal input end 83, wherein the fourth resistor 81, the fourth diode 82 and the full-turning signal input end 83 are used for controlling the MOS tube switch unit 4 to be turned off and do not work and are connected in sequence, the cathode of the fourth diode 82 is connected with the fourth resistor 81, the anode of the fourth diode 82 is connected with the full-turning signal input end 83, and the full-turning signal input end 83 is connected with the full-turning signal output end in the charger. When the utility model is used, the power output V + end 1 and the power output V-end 2 are respectively connected with the positive electrode and the negative electrode of the charger output interface to be electrified, so that the load interface 3 in the utility model is equivalent to the charger output interface and is used for connecting a load battery; when the charger is connected with the mains supply and powered on, and the V + end 31 (equivalent to the positive pole) and the switch control end 32 (equivalent to the negative pole) of the load interface 3 are connected with the positive pole and the negative pole of the battery load 6, the reverse connection prevention protection circuit 7 cannot work, and the starting circuit unit 5 works to control the MOS tube switch unit 4 to be conducted so as to realize the normal charging of the load battery; when the switch control end 32 (equivalent to the negative pole) and the V + end 31 (equivalent to the positive pole) of the load interface 3 are connected with the positive pole and the negative pole of the battery load 6, that is, when the connection is reversed, the positive pole of the battery load 6 is connected to the negative pole of the battery load 6 through the photoelectric coupler 71 by the switch control end 32, the first diode 72, the divider resistor R9 and the V + end 31 to form a loop, because the photoelectric coupler 71 is conducted, the positive voltage of the charger is conducted through the large divider resistor 712 and the photoelectric coupler 71 to provide forward bias for the third triode 73, the third triode 73 is conducted to short-circuit the control voltage of the MOS transistor switch unit 4, and the MOS transistor switch unit 4 is closed, thereby achieving the purpose of preventing the reverse connection without burning the circuit and the charger circuit board, and ensuring the service life of the product, making the charger safer to use, and having extremely strong market competitiveness. Furthermore, when the charger charges the battery load, the charging current is larger than the lamp-turning current value, the lamp-turning signal 83 inputs high potential, and provides a high level to the G pole of the MOS transistor switch unit 4 after passing through the fourth diode 82 and the fourth resistor 81, so as to maintain the conduction of the MOS transistor switch unit 4, the charging current will decrease along with the rise of the battery voltage, when the charging current is smaller than the lamp-turning current value, the lamp-turning signal 83 changes from high level to low level, the fourth diode 82 is cut off, and the battery voltage tends to be equal to the charger voltage, the battery is fully charged, the voltages on the B pole and the E pole of the second triode 52 tend to be equal to 0V, therefore the start circuit unit 5 which is conducted cannot be conducted, therefore the MOS transistor switch unit 4 is cut off and does not work, at this moment, the power output V-terminal 2 is disconnected with the battery load, so that the charger cannot charge the, and a hundred percent turn-off circuit is realized to control the battery load not to be charged, so that the loss is reduced. Additionally, the utility model discloses be applied to a little PCB board, with charger independent design, additionally add little PCB board on the charger promptly, make the charger have prevent reverse-connection protect function and fill the function that fully turn-offs and stop charging, realize multistage safeguard function to the work of supplementary charger charging is applicable to various chargers.

The resistance of the voltage dividing large resistor 712 is 100k Ω. The model of the photoelectric coupler 71 is LTV-357T-C; the model of the third triode 73 is SS 8050.

A voltage dividing resistor R9 is further connected between the cathode of the first diode 72 and the V + terminal 31, and the resistance of the resistor R9 is 5.6k Ω.

The starting circuit unit 5 includes a first triode 51, a second triode 52 for controlling the conduction of the first triode 51, and a first capacitor 53 connected between the e pole and the b pole of the first triode 51 and having a charging delay function, the e pole of the first triode 51 is connected to the V + terminal 1 of the power output, the c pole of the first triode 51 is connected to the MOS switch unit 4, the b pole of the second triode 52 is connected to the switch control terminal 32, the c pole of the second triode 52 is connected to the b pole of the first triode 51, and the e pole of the second triode 52 is connected to the V-terminal 2 of the power output. The fourth resistor 81 is connected to the G-pole of the first MOS transistor 41 and the c-pole of the first transistor 51. When the c-pole of the first transistor 51 outputs a high level, the high level is provided to the G-pole of the first MOS transistor 41 and the G-pole of the second MOS transistor 42, so as to control the first MOS transistor 41 and the second MOS transistor 42 to be simultaneously turned on. When the battery load 6 is connected with the load interface 3, the reverse connection preventing protection circuit 7 will not work, and the starting circuit unit 5 works, the starting circuit unit 5 and the load battery form a complete loop, at this time, the negative electrode of the load battery 6 will provide the b pole potential in the second triode 52, so that the second triode 52 is conducted and amplified, and the c pole of the second triode pulls down the b pole potential in the first triode 51, so that the first triode 51 is also conducted, so that the loop formed by the starting circuit unit 5 and the load battery is conducted, at this time, the c pole of the first triode 51 will provide a high level for the MOS tube switch unit 4 to drive the MOS tube switch unit 4 to conduct, so that the power output V + end 1, the power output V-end 2, the load battery 6 and the MOS tube switch unit 4 form a through circuit, thereby realizing the charging of the load battery 6, and because first electric capacity 53 can charge the time delay, make the slow step-down of b utmost point electric potential in the first triode 51, play the purpose of time delay to can not switch on in the twinkling of an eye that load interface 3 is connected with load battery 6, but postpone earlier, switch on again, prevent to produce the spark in the twinkling of an eye when being connected with load battery 6 with this, in order to have the function of preventing striking sparks, make the charger use safer, the order the utility model discloses extremely strong market competition has. The charger has the functions of preventing sparking, preventing reverse connection and stopping charging after full charging and shutdown.

A resistor R6 is further connected between the b-pole of the second transistor 52 and the switch control terminal 32, and a resistor R4 is further connected between the c-pole of the second transistor 52 and the b-pole of the first transistor 51.

The MOS switch unit 4 includes a first MOS transistor 41 and a second MOS transistor 42, the G pole of the first MOS transistor 41 is connected to the c pole of the third transistor 73, the G pole of the first MOS transistor 41 is further connected to the c pole of the first transistor 51, the G pole of the first MOS transistor 41 is further connected to the G pole of the second MOS transistor 42 after being connected to a resistor R7, the D pole of the second MOS transistor 42 is connected to the switch control terminal 32, the S pole of the first MOS transistor 41 is connected to the S pole of the second MOS transistor 42, and the D pole of the second MOS transistor 42 is connected to the power output V-terminal 2. When the c-pole of the first transistor 51 outputs a high level, the high level is provided to the G-pole of the first MOS transistor 41 and the G-pole of the second MOS transistor 42, so as to control the first MOS transistor 41 and the second MOS transistor 42 to be simultaneously turned on.

The S pole and the G pole of the second MOS transistor 42 are further connected to a second capacitor 421 having a charging delay function; the G pole of the first MOS tube 41 and the power output V-end 2 are also connected with a voltage stabilizing diode 43. Because of charger the inside device has a plurality of electrolytic capacitor, the charger is not connected city electric conduction, when connecting load battery 6 with load interface 3, establish ties because of resistance R7 and second electric capacity 421, load battery 6 charges to second electric capacity 421, voltage can slowly rise, second electric capacity 421 and second MOS pipe 42' S the G utmost point promptly, the S utmost point is parallelly connected, lead to second MOS pipe 42 also can postpone to switch on, MOS pipe switch unit 4 postpones to switch on, in load battery 6 and load interface 3 contact period like this, load battery 6 can not contact in the twinkling of an eye and charge to a plurality of electrolytic capacitor in the charger, in order to have the function of preventing striking sparks, make the charger use safelyr, the order the utility model discloses extremely strong market competition has.

A resistor R3 is further connected in parallel across the first capacitor 53. A resistor R12 is further connected in parallel across the second capacitor 421. A resistor R11, a resistor R5 and a resistor R2 are further connected between the G electrode of the first MOS transistor 41 and the c electrode of the first triode 51. The model of the first triode 51 is MMBT 5401; the second triode 52 is of the type MMBT 5551. The model of the first MOS transistor 41 is NCE 1540K; the second MOS transistor 42 is of the type NCE 1540K.

To sum up, when the utility model is used, the power output V + end 1 and the power output V-end 2 are respectively connected with the positive electrode and the negative electrode of the charger output interface to be electrified, so that the load interface 3 in the utility model is equivalent to the charger output interface and is used for connecting a load battery; when the charger is connected with the mains supply and powered on, and the V + end 31 (equivalent to the positive pole) and the switch control end 32 (equivalent to the negative pole) of the load interface 3 are connected with the positive pole and the negative pole of the battery load 6, the reverse connection prevention protection circuit 7 cannot work, and the starting circuit unit 5 works to control the MOS tube switch unit 4 to be conducted so as to realize the normal charging of the load battery; when the switch control end 32 (equivalent to the negative pole) and the V + end 31 (equivalent to the positive pole) of the load interface 3 are connected with the positive pole and the negative pole of the battery load 6, that is, when the connection is reversed, the positive pole of the battery load 6 is connected to the negative pole of the battery load 6 through the photoelectric coupler 71 by the switch control end 32, the first diode 72, the divider resistor R9 and the V + end 31 to form a loop, because the photoelectric coupler 71 is conducted, the positive voltage of the charger is conducted through the large divider resistor 712 and the photoelectric coupler 71 to provide forward bias for the third triode 73, the third triode 73 is conducted to short-circuit the control voltage of the MOS transistor switch unit 4, and the MOS transistor switch unit 4 is closed, thereby achieving the purpose of preventing the reverse connection without burning the circuit and the charger circuit board, and ensuring the service life of the product, making the charger safer to use, and having extremely strong market competitiveness. Furthermore, when the charger charges the battery load, the charging current is larger than the lamp-turning current value, the lamp-turning signal 83 inputs high potential, and provides a high level to the G pole of the MOS transistor switch unit 4 after passing through the fourth diode 82 and the fourth resistor 81, so as to maintain the conduction of the MOS transistor switch unit 4, the charging current will decrease along with the rise of the battery voltage, when the charging current is smaller than the lamp-turning current value, the lamp-turning signal 83 changes from high level to low level, the fourth diode 82 is cut off, and the battery voltage tends to be equal to the charger voltage, the battery is fully charged, the voltages on the B pole and the E pole of the second triode 52 tend to be equal to 0V, therefore the start circuit unit 5 which is conducted cannot be conducted, therefore the MOS transistor switch unit 4 is cut off and does not work, at this moment, the power output V-terminal 2 is disconnected with the battery load, so that the charger cannot charge the, and a hundred percent turn-off circuit is realized to control the battery load not to be charged, so that the loss is reduced. Additionally, the utility model discloses be applied to a little PCB board, with charger independent design, additionally add little PCB board on the charger promptly, make the charger have prevent reverse-connection protect function and fill the function that fully turn-offs and stop charging, realize multistage safeguard function to the work of supplementary charger charging is applicable to various chargers.

Of course, the above description is only an exemplary embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes and modifications made by the constructions, features, and principles of the present invention in accordance with the claims of the present invention are intended to be included in the scope of the present invention.

Claims

1. The utility model provides a charger auxiliary circuit that charges of multistage protection which characterized in that: the charger comprises a power output V + end (1) connected with the positive pole and the negative pole of a charger output interface, a power output V-end (2), a load interface (3) connected between the power output V + end (1) and the power output V-end (2), a MOS tube switch unit (4) and a starting circuit unit (5), wherein the load interface (3) is provided with a V + end (31) and a switch control end (32) which are respectively used for being connected with the positive pole and the negative pole of a battery load (6), the V + end (31) is connected with the power output V + end (1), the switch control end (32) is connected with the MOS tube switch unit (4), an anti-reverse connection protection circuit (7) is connected between the V + end (31) and the switch control end (32), the anti-reverse connection protection circuit (7) comprises a photoelectric coupler (71), the first pin of the photoelectric coupler (71) is connected with the switch control end (32), the second pin of the photoelectric coupler (71) is connected with the anode of a first diode (72), the cathode of the first diode (72) is connected with the V + end (31), a delay capacitor (711) is connected between the third pin and the fourth pin of the photoelectric coupler (71), the fourth pin of the photoelectric coupler (71) is also connected with a voltage dividing large resistor (712) and then is connected with a power output V + end (1), the third pin of the photoelectric coupler (71) is connected with the b pole of a third triode (73), the e pole of the third triode (73) is connected with a power output V-end (2), and the c pole of the third triode (73) is connected with the MOS tube switching unit (4) and the starting circuit unit (5); the charger charging auxiliary circuit further comprises a fourth resistor (81), a fourth diode (82) and a full-charge turning signal input end (83), wherein the fourth resistor (81), the fourth diode (82) and the full-charge turning signal input end (83) are used for controlling the MOS tube switch unit (4) to be switched off and do not work and are connected in sequence, the cathode of the fourth diode (82) is connected with the fourth resistor (81), the anode of the fourth diode (82) is connected with the full-charge turning signal input end (83), and the full-charge turning signal input end (83) is connected with a full-charge turning signal output end in the charger.

2. The multi-stage protection charger charging auxiliary circuit of claim 1, wherein: the model of the photoelectric coupler (71) is LTV-357T-C; the model of the third triode (73) is SS 8050.

3. The multi-stage protection charger charging auxiliary circuit of claim 1, wherein: a voltage dividing resistor R9 is also connected between the cathode of the first diode (72) and the V + end (31), and the resistance value of the resistor R9 is 5.6k omega.

4. The multi-stage protection charger charging auxiliary circuit according to any one of claims 1 to 3, wherein: the starting circuit unit (5) comprises a first triode (51), a second triode (52) used for controlling the conduction of the first triode (51) and a first capacitor (53) which is connected between the e pole and the b pole of the first triode (51) and has a charging delay function, the e pole of the first triode (51) is connected with the V + end (1) of the power output, the c pole of the first triode (51) is connected with the MOS tube switch unit (4), the b pole of the second triode (52) is connected with the switch control end (32), the c pole of the second triode (52) is connected with the b pole of the first triode (51), and the e pole of the second triode (52) is connected with the V-end (2) of the power output.

5. The multi-stage protection charger charging auxiliary circuit of claim 4, wherein: the MOS tube switch unit (4) comprises a first MOS tube (41) and a second MOS tube (42), the G pole of the first MOS tube (41) is connected with the c pole of the third triode (73), the G pole of the first MOS tube (41) is also connected with the G pole of the second MOS tube (42) after being connected with a resistor R7, the D pole of the second MOS tube (42) is connected with the switch control end (32), the S pole of the first MOS tube (41) is connected with the S pole of the second MOS tube (42), and the D pole of the second MOS tube (42) is connected with the power output V-end (2); and the fourth resistor (81) is connected with the G pole of the first MOS tube (41) and the c pole of the first triode (51).

6. The multi-stage protection charger charging auxiliary circuit of claim 4, wherein: a resistor R6 is connected between the b pole of the second triode (52) and the switch control end (32), and a resistor R4 is connected between the c pole of the second triode (52) and the b pole of the first triode (51).

7. The multi-stage protection charger charging auxiliary circuit of claim 5, wherein: the S pole and the G pole of the second MOS tube (42) are also connected with a second capacitor (421) with a charging time delay function; the G pole of the first MOS tube (41) and the power output V-end (2) are also connected with a voltage stabilizing diode (43).

8. The multi-stage protection charger charging auxiliary circuit of claim 7, wherein: a resistor R3 is also connected in parallel at two ends of the first capacitor (53); and a resistor R12 is also connected in parallel at two ends of the second capacitor (421).

9. The multi-stage protection charger charging auxiliary circuit of claim 5, wherein: and a resistor R11, a resistor R5 and a resistor R2 are also connected between the G pole of the first MOS transistor (41) and the c pole of the first triode (51).

10. The multi-stage protection charger charging auxiliary circuit of claim 5, wherein: the model of the first triode (51) is MMBT 5401; the model of the second triode (52) is MMBT 5551; the model of the first MOS tube (41) is NCE 1540K; the model of the second MOS tube (42) is NCE 1540K.