Charging circuit capable of switching power supply

Abstract

The utility model discloses a charging circuit capable of switching a power supply. The charging circuit comprises a switching power supply, a solar controller, a storage battery, a relay, an operational amplifier, a photoelectric coupler, a Darlington transistor array, a DC-DC isolation power supply module, a single-chip microcomputer, a voltage stabilization source and a synchronous switch voltage reduction converter integrated with various fast charging protocols. The synchronous switch step-down converter preferentially uses a storage battery as a power supply, and the power supply is output through an interface terminal connected with the synchronous switch step-down converter after conversion so as to charge a shared power bank or a mobile phone. Meanwhile, the voltage of the storage battery is detected by using the single-chip microcomputer and compared with a threshold voltage value set in the single-chip microcomputer, and then the switching power supply or the storage battery is switched to serve as a power supply of the synchronous switch step-down converter by combining modules such as an operational amplifier, a photoelectric coupler, a relay and a Darlington transistor array. According to the charging circuit capable of switching the power supply, the threshold voltage can be conveniently and accurately set, so that solar energy is fully utilized to charge a shared power bank or a mobile phone.

Description

TECHNICAL FIELD

[0001] The utility model relates to dual power supply charging technical field especially, it relates to a charging circuit of switchable power supply. BACKGROUND

[0002] At present, the function of smart mobile phone is more and more powerful, has become an indispensable part in people's life, simultaneously, the time of using mobile phone of people every day is in lengthening, although the capacity of mobile phone battery is big, but the power consumption speed of battery is still very fast, when going out, if meeting the mobile phone power consumption, and not having the power bank, will bring a lot of inconvenience. In order to solve the problem of inconvenient charging of mobile phone in the open air, people designed the circuit for outdoor mobile phone charging (for example, the application number 2024202904442 "a dual power supply switching charging circuit"), the circuit sets the threshold voltage of power supply switching by using fixed resistance, in actual application, when needing to change the threshold voltage, it needs to replace the resistance, causes the inconvenience of setting, in addition, the threshold voltage set by resistance is not accurate enough. CONTENT OF UTILITY MODEL

[0003] The utility model aims at overcoming the insufficient of prior art, provide a charging circuit of switchable power supply.

[0004] The utility model is realized through the following technical schemes:

[0005] A charging circuit of switchable power supply, including a switching power supply, the solar energy controller of connection to solar panel, battery, relay, operational amplifier, photoelectric coupler, darlington transistor array, DC-DC isolation power module, singlechip, regulated power supply and integrated multiple fast charging protocol synchronous switch buck converter;

[0006] The input of solar energy controller is connected to solar panel, the battery end of solar energy controller is connected to battery, the positive voltage end of solar energy controller load end is connected to the normally closed contact of relay, the output of switching power supply is connected the normally open contact of relay, the common contact of relay is connected to the voltage input of synchronous switch buck converter, synchronous switch buck converter is connected to interface terminal, interface terminal is used for connecting shared power bank or mobile phone, and power supply is provided for it;

[0007] The positive and negative poles of battery are connected to the noninverting input and inverting input of operational amplifier respectively, the output of operational amplifier is connected to the inverting input of operational amplifier in feedback, the noninverting input of operational amplifier is also connected to the 0V end of DC-DC isolation power module, and the input of DC-DC isolation power module is connected to the output of switching power supply;

[0008] The output end of the operational amplifier is also connected to the AD conversion pin of the single-chip microcomputer, and the power supply ends of the operational amplifier and the single-chip microcomputer are both connected to the VCC5V end of the DC-DC isolation power supply module; the AD reference voltage pin of the single-chip microcomputer is connected to the reference end and cathode of the voltage regulator, and the voltage regulator is connected to the 0V end and VCC5V end of the DC-DC isolation power supply module; one of the output pins of the single-chip microcomputer is connected to the cathode of the photoelectric coupler, and the anode of the photoelectric coupler is connected to the VCC5V end of the DC-DC isolation power supply module; the collector of the photoelectric coupler is connected to the output end of the switching power supply and is connected to the input pin of the Darlington transistor array; one end of the relay coil is connected to the output end of the switching power supply, and the other end is connected to the output pin of the Darlington transistor array. At the same time, a freewheeling diode is connected in parallel at both ends of the relay coil.

[0009] In the above technical solution, the synchronous switching buck converter model is IP6505T.

[0010] In the above technical solution, a fuse is connected between the voltage input terminal of the synchronous switching buck converter and the common contact of the relay.

[0011] In the above technical solution, the model of the Darlington transistor array is ULN2004A.

[0012] In the above technical solution, the input end of the DC-DC isolated power supply module is connected to the output end of the switching power supply through a fuse.

[0013] In the above technical solution, the model of the voltage stabilizing source is TL431.

[0014] In the above technical solution, the VOUT pin of the synchronous switching buck converter is connected to the VCC pin of the interface terminal for voltage feedback; the DP pin and DM pin of the synchronous switching buck converter are connected to the corresponding pins of the interface terminal as USB fast charging identification signals; the SW pin of the synchronous switching buck converter is connected to the VCC pin of the interface terminal after passing through the inductor as the charging voltage.

[0015] In the above technical solution, the VCC pin of the interface terminal is also connected to an indicator light through a resistor to indicate whether the circuit can work normally.

[0016] The advantages and beneficial effects of the utility model are:

[0017] 1. The low-voltage threshold voltage value VL and the high-voltage threshold voltage value VH of the utility model can be conveniently set in the microcontroller program according to actual needs. Compared with the setting method using resistors, it is more convenient and accurate (for example, the "Dual Power Switching Charging Circuit" with application number 2024202904442 requires the use of fixed resistors to set the threshold voltage value, which is not convenient and accurate enough). U6 in the utility model generates the voltage reference for AD conversion, and U7 is powered by the 12V output of the switching power supply and outputs 5V for use by operational amplifiers, microcontrollers, voltage regulators, and optocouplers. It has a reasonable design and reliable operation.

[0018] 2. The utility model can fully utilize solar energy to charge shared power banks or mobile phones by switching power sources, thereby reducing charging costs.

[0019] 3. This utility model supports multiple fast charging protocols, providing convenient and fast outdoor charging for shared power banks or mobile phones. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a circuit principle diagram of the charging circuit of the switchable power supply of the utility model.

[0021] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0022] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with specific embodiments.

[0023] A charging circuit with switchable power supply, such as Figure 1 As shown, the system primarily includes a 12V switching power supply, a solar controller connected to the solar panel, a 12V battery, a relay, an operational amplifier, an optocoupler, a Darlington transistor array, a voltage regulator, a DC-DC isolated power supply module, a single-chip microcomputer, and a synchronous switching buck converter that integrates multiple fast-charging protocols. The following details its structure and operating principle.

[0024] The solar controller has an input end, a battery end and a load end. The input end is connected to the solar panel, the battery end is connected to the 12V battery, and the load end is used to connect to the electrical equipment. The solar controller can protect the battery to prevent it from overcharging and over-discharging, and ensure that it can provide stable and reliable power supply to the electrical equipment connected to the load end. The voltage of the load end is consistent with the battery voltage.

[0025] The positive voltage terminal UDC of the solar controller load end is connected to the normally closed contact of relay K1, the +12V output terminal P12 of the switching power supply is connected to the normally open contact of relay K1, and the common contact of relay K1 is connected to the VIN pin of the synchronous switching buck converter U1 (model IP6505T) through the fuse F1, thereby switching the power supply of the synchronous switching buck converter U1 through relay K1; the VOUT pin of the synchronous switching buck converter U1 is connected to the VCC pin of the interface terminal X1 for voltage feedback; the DP and DM pins of the synchronous switching buck converter U1 are connected to the corresponding pins of the interface terminal X1 as the USB fast charging identification signal; the SW pin of the synchronous switching buck converter U1 is connected to the VCC pin of the interface terminal X1 after passing through the inductor L1 as the charging voltage; the interface terminal X1 is used to connect to a shared power bank or mobile phone to power it. Furthermore, the VCC pin of the interface terminal X1 is also connected to the indicator light D1 through the resistor R2 to indicate whether the circuit is working properly.

[0026] The positive and negative poles of the battery are respectively connected to the non-inverting input and inverting input of the operational amplifier U2 through resistors R4 and R3. The output of the operational amplifier U2 is fed back to the inverting input of the operational amplifier U2 through resistor R5. The non-inverting input of the operational amplifier U2 is also connected to the 0V end (i.e., M1) of the DC-DC isolation power supply module U7 through resistor R6. The input end Vin of the DC-DC isolation power supply module U7 is connected to the +12V output end P12 of the switching power supply through the fuse F2. In this way, the 12V DC output by the switching power supply powered by 220V AC is used to power the DC-DC isolation power supply module U7, and the DC-DC isolation power supply module U7 outputs VCC5V and 0V.

[0027] The output end of the operational amplifier U2 is also connected to the AD conversion pin of the single-chip computer U3 through the resistor R7. The power supply ends of the operational amplifier U2 and the single-chip computer U3 are both connected to the VCC5V end of the DC-DC isolation power supply module U7, so that the DC-DC isolation power supply module U7 supplies power to the operational amplifier U2 and the single-chip computer U3; the AD reference voltage pin of the single-chip computer U3 is connected to the reference end and cathode of the voltage regulator U6 (model TL431), and the voltage regulator U6 is connected to the 0V end (i.e., M1) of the DC-DC isolation power supply module U7, and is connected to the VCC5V end of the DC-DC isolation power supply module U7 through the resistor R10; the single-chip computer One of the output pins of U3 is connected to the cathode of the optocoupler U4, and the anode of the optocoupler U4 is connected to the VCC5V terminal of the DC-DC isolation power supply module U7 through a resistor R8; the collector of the optocoupler U4 is connected to the +12V output terminal P12 of the switching power supply through a resistor R9, and is connected to the input pin of the Darlington transistor array U5 (model ULN2004A); one end of the coil K1A of the relay K1 is connected to the +12V output terminal P12 of the switching power supply, and the other end is connected to the output pin of the Darlington transistor array U5. At the same time, the two ends of the coil K1A of the relay K1 are also connected in parallel with a freewheeling diode V1.

[0028] The usage and working principle of the charging circuit of the switchable power supply of the utility model are as follows:

[0029] Synchronous switching buck converter U1 preferentially uses a battery as its power supply. After conversion, it outputs the converted power through its connected interface terminal X1 for charging a shared power bank or mobile phone. As the battery power is depleted, the battery voltage drops. When the microcontroller U3 detects that the battery voltage has dropped to the set low-voltage threshold voltage value VL, it is considered that the battery power is insufficient. The output pin signal of microcontroller U3 connected to the optocoupler U4 changes from low to high, causing the voltage at the collector of optocoupler U4 to change from low to high. After input into the Darlington transistor array U5, the coil of relay K1 is energized, the normally closed contact of relay K1 opens, and the normally open contact closes, switching the power supply of synchronous switching buck converter U1 to the +12V output terminal (P12) of the switching power supply. The 12V DC output of the switching power supply powered by 220V AC power supplies synchronous switching buck converter U1.

[0030] When the sunlight is sufficient, the solar panel charges the battery, the battery voltage rises, when the single-chip microcomputer U3 detects that the voltage of the battery rises to the set high voltage threshold voltage value VH, it is considered that the battery is suitable for continuing to discharge, at this time the output pin signal of the single-chip microcomputer U3 changes from high level to low level, the voltage of the collector of the photoelectric coupler U4 changes from high to low, after inputting the Darlington transistor array U5, the coil of the relay K1 loses power and acts, the normally closed contact of the relay K1 is closed, the normally open contact is disconnected, and the power supply of the synchronous switch voltage reduction converter U1 is switched to the battery power supply.

[0031] The low voltage threshold voltage value VL and the high voltage threshold voltage value VH of the utility model can be conveniently set in the single-chip microcomputer program according to actual requirements. U6 generates the voltage reference for AD conversion, U7 is powered by the 12V output by the switching power supply, and outputs 5V for use by the operational amplifier, single-chip microcomputer, voltage stabilizer and photoelectric coupler.

[0032] The above has made the exemplary description of the utility model, it should be explained that, without departing from the core of the utility model, any simple deformation, modification or other equivalent replacement of the person skilled in the art without spending creative labor falls into the protection scope of the utility model.

Claims

1. A charging circuit with a switchable power supply, characterized in that: It includes a switching power supply, a solar controller connected to the solar panel, a battery, a relay, an operational amplifier, an optocoupler, a Darlington transistor array, a DC-DC isolated power supply module, a microcontroller, a voltage regulator, and a synchronous switching buck converter that integrates multiple fast charging protocols; The input end of the solar controller is connected to the solar panel, the battery end of the solar controller is connected to the battery, the positive voltage end of the load end of the solar controller is connected to the normally closed contact of the relay, the output end of the switching power supply is connected to the normally open contact of the relay, the common contact of the relay is connected to the voltage input end of the synchronous switching buck converter, and the synchronous switching buck converter is connected to the interface terminal, which is used to connect to a shared power bank or mobile phone to power it; The positive and negative poles of the battery are respectively connected to the non-inverting input and inverting input of the operational amplifier. The output of the operational amplifier is fed back to the inverting input of the operational amplifier. The non-inverting input of the operational amplifier is also connected to the 0V terminal of the DC-DC isolated power supply module. The input of the DC-DC isolated power supply module is connected to the output of the switching power supply. The output end of the operational amplifier is also connected to the AD conversion pin of the single-chip microcomputer, and the power supply ends of the operational amplifier and the single-chip microcomputer are both connected to the VCC5V end of the DC-DC isolation power supply module; the AD reference voltage pin of the single-chip microcomputer is connected to the reference end and cathode of the voltage regulator, and the voltage regulator is connected to the 0V end and VCC5V end of the DC-DC isolation power supply module; one of the output pins of the single-chip microcomputer is connected to the cathode of the photoelectric coupler, and the anode of the photoelectric coupler is connected to the VCC5V end of the DC-DC isolation power supply module; the collector of the photoelectric coupler is connected to the output end of the switching power supply and is connected to the input pin of the Darlington transistor array; one end of the relay coil is connected to the output end of the switching power supply, and the other end is connected to the output pin of the Darlington transistor array. At the same time, a freewheeling diode is connected in parallel at both ends of the relay coil.

2. The charging circuit of a switchable power supply according to claim 1, wherein: The synchronous switching buck converter model is IP6505T.

3. The charging circuit of a switchable power supply according to claim 1, wherein: A fuse is connected between the voltage input of the synchronous switching buck converter and the common contact of the relay.

4. The charging circuit of a switchable power supply according to claim 1, wherein: The model of the Darlington transistor array is ULN2004A.

5. The charging circuit of a switchable power supply according to claim 1, wherein: The input end of the DC-DC isolation power supply module is connected to the output end of the switching power supply through a fuse.

6. The charging circuit of a switchable power supply according to claim 1, wherein: The model of the voltage stabilizing source is TL431.

7. The charging circuit of a switchable power supply according to claim 1, wherein: The VOUT pin of the synchronous switching buck converter is connected to the VCC pin of the interface terminal for voltage feedback; the DP pin and DM pin of the synchronous switching buck converter are connected to the corresponding pins of the interface terminal as USB fast charging identification signals; the SW pin of the synchronous switching buck converter is connected to the VCC pin of the interface terminal after passing through the inductor as the charging voltage.

8. The charging circuit of a switchable power supply according to claim 1, wherein: The VCC pin of the interface terminal is also connected to an indicator light through a resistor to indicate whether the circuit is working properly.

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