CN118713270A - Automatic transfer switch circuit and electronic equipment thereof - Google Patents

Abstract

The present invention application relates to an automatic switching switch circuit and electronic equipment, wherein a DC boost circuit performs boosting or voltage stabilization according to a received first external power supply signal, and outputs a first voltage signal to a DC buck circuit, the DC buck circuit steps down the received first voltage signal, and outputs a second voltage signal to a power supply switching circuit to supply power to a load; when daytime is switched to nighttime, a 220V AC power supply is connected to a front control circuit, a switch in the front control circuit is turned on, and a first control signal is output to a power supply switching circuit, the power supply switching circuit cuts off the current channel between the DC buck circuit and the power supply switching circuit according to the first control signal, and a third external power supply outputs a third voltage signal through the power supply switching circuit to supply power to the load. The present application can not only make adjustments when the output voltage of the first external power supply floats, ensuring that the DC buck circuit can output a stable second voltage signal to supply power to the load, but also can realize rapid switching of the load between battery power supply and AC power supply.

Description

Automatic transfer switch circuit and electronic equipment thereof

Technical Field

The present application relates to the field of switch technology, and in particular to an automatic transfer switch circuit and electronic equipment.

Background Art

Everywhere on the street, you can see a solar panel plus a battery pack next to some outdoor equipment such as street lights or surveillance. The solar panel absorbs sunlight and converts light energy directly into electrical energy and stores it in the battery pack for output. However, as the intensity of sunlight changes, the amount of solar charging decreases or increases or decreases. Under the combined effect of solar charging and electrical power consumption, the amount of power in the battery pack changes, especially at night, when the amount of solar charging is almost zero. The reduction in the amount of power in the battery pack causes the output voltage of the battery pack to be lower than the rated working voltage required by the load. During the day when there is plenty of sunlight, after a period of solar charging, the battery pack retains more power, and its output voltage is generally higher than the rated working voltage required by the load. When the amount of power stored in the battery changes significantly, its output voltage does not match the rated working voltage required by the load, which can easily cause the load to not work or burn out directly. If the battery pack is insufficient, an external power supply must be connected to power the load, so it is also necessary to consider how to switch between battery power supply and external power supply.

Summary of the invention

Based on this, it is necessary to provide an automatic switching switch circuit and its electronic equipment to solve the problems of unsafe load power supply caused by floating output voltage of the existing battery pack and how to switch power supply from battery pack to mains power supply.

An automatic transfer switch circuit, comprising:

A DC boost circuit, the DC boost circuit is connected to a first external power source, and the DC boost circuit is configured to convert a received first external power source signal to obtain a first voltage signal;

a DC step-down circuit, the DC step-down circuit being connected to the DC step-up circuit and the power supply switching circuit, the DC step-down circuit being configured to convert the received first voltage signal and transmit a second voltage signal to the power supply switching circuit;

A front control circuit, the front control circuit is connected to the power supply switching circuit and the second external power supply respectively, and the front control circuit is configured to convert and process the received second external power supply signal and transmit the first control signal to the power supply switching circuit;

A power supply switching circuit, wherein the power supply switching circuit is respectively connected to a third external power supply, the DC step-down circuit, and the front control circuit; the power supply switching circuit is configured to convert and process the received first control signal to obtain a second control signal; the third external power supply is configured to transmit a third voltage signal to the power supply switching circuit, and the power supply switching circuit is also configured to switch and output the second voltage signal and the third voltage signal according to the second control signal.

In one of the embodiments, the power supply switching circuit includes a first switching circuit and a second switching circuit;

The first switching circuit is connected to the pre-control circuit and the second switching circuit respectively, and the second switching circuit is connected to the DC step-down circuit; the first switching circuit is configured to convert and process the received first control signal and transmit the second control signal to the second switching circuit; the second switching circuit is configured to switch and output the second voltage signal and the third voltage signal according to the second control signal.

In one embodiment, the first switching circuit includes a first triode and a second triode, and the second switching circuit is two sets of converted eight-pin relays;

The base of the second transistor is connected to the second output end of the pre-control circuit, and the first output end of the pre-control circuit is connected to the collector of the first transistor, the collector of the second transistor, and the first pin of the second switching circuit; the emitter of the second transistor is connected to the base of the first transistor, and the emitter of the first transistor is connected to the eighth pin of the second switching circuit and the second input end of the third external power supply. The first pin of the second switching circuit is connected to the sixteenth pin of the second switching circuit through a coil, and the sixteenth pin of the second switching circuit is connected to the ninth pin of the second switching circuit and the first input end of the third external power supply. The fourth pin and the thirteenth pin of the second switching circuit are respectively connected to the first output end and the second output end of the DC step-down circuit.

In one embodiment, the front control circuit includes: a rectifier circuit, an optocoupler relay, and an optocoupler drive circuit. The input end of the rectifier circuit is connected to the second external power supply, the output end of the rectifier circuit is connected to the input end of the optocoupler drive circuit, the output end of the optocoupler drive circuit is connected to the input end of the optocoupler relay, and the output end of the optocoupler relay is connected to the power supply switching circuit.

In one embodiment, the optocoupler driving circuit includes a first resistor, a second resistor, a third resistor, and a first diode; the first output end of the rectifier circuit is connected to the second end of the second resistor, the second output end of the rectifier circuit is connected to the first end of the third resistor, the positive electrode of the first diode, and the second input end of the optocoupler relay, the first end of the second resistor is connected to the second end of the third resistor, the first end of the first resistor and the cathode of the first diode, and the second end of the first resistor is connected to the first input end of the optocoupler relay.

In one of the embodiments, the DC step-down circuit includes a step-down switching regulator, a first capacitor, a second capacitor, a first inductor, and a second diode;

The fifth pin of the step-down switching regulator is connected to the second end of the first inductor, the first end of the first capacitor, and the fourth pin of the second switching circuit; the third pin of the step-down switching regulator is connected to the anode of the second diode, the cathode of the second capacitor, the second end of the first capacitor, and the thirteenth pin of the second switching circuit; the first end of the first inductor, the cathode of the second diode, and the second pin of the step-down switching regulator are connected to each other; and the first pin of the step-down switching regulator is connected to the anode of the second capacitor.

In one embodiment, the DC boost circuit includes a boost IC chip, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and a third diode;

The first end of the third capacitor is connected to the first end of the fourth capacitor, the first end of the fourth resistor, the first end of the sixth resistor, the cathode of the third diode, the seventh pin of the boost IC chip, the eighth pin of the boost IC chip, the first end of the second inductor, and the first input end of the DC step-down circuit; the second end of the third capacitor is connected to the second end of the fourth capacitor, the second end of the fifth resistor, the fifth pin of the boost IC chip, the sixth pin of the boost IC chip, the second end of the sixth capacitor, the second end of the seventh capacitor, the second end of the eighth capacitor, the second end of the ninth capacitor, and the second input end of the DC step-down circuit; the second end of the fourth resistor is connected to the first end of the fifth resistor, the second end of the fifth capacitor, and the third pin of the boost IC chip; the fourth pin of the boost IC chip is connected to the first end of the seventh resistor, and the second end of the seventh resistor is connected to the first end of the sixth capacitor; the second pin of the boost IC chip is connected to the first end of the seventh capacitor, and the first pin of the boost IC chip is connected to the second end of the second inductor, the first end of the eighth capacitor, and the first end of the ninth capacitor.

In one embodiment, the first external power source is a battery pack.

In one embodiment, the second external power supply is a 220V AC input.

In one embodiment, the third external power source includes an inverter power circuit, and the output end of the second external power source is connected to the input end of the inverter power circuit.

In a second aspect, an embodiment of the present invention further provides an electronic device, the electronic device comprising the automatic transfer switch circuit and a load as described above, the automatic transfer switch circuit being connected to the load, and the automatic transfer switch circuit supplying power to the load.

One of the above technical solutions has the following advantages and beneficial effects:

In each embodiment of the above-mentioned automatic conversion switch circuit, a DC boost circuit, a DC buck circuit, a front control circuit and a power supply switching circuit are included. Based on the connection between the DC boost circuit and the DC buck circuit, the power supply switching circuit is respectively connected to the DC buck circuit and the front control circuit; the DC boost circuit is configured to convert and process the received first external power supply signal to obtain a first voltage signal; the DC buck circuit is configured to convert and process the received first voltage signal, and transmit a second voltage signal to the power supply switching circuit, thereby providing a stable voltage output; the front control circuit is configured to convert and process the received second external power supply signal, and transmit a first control signal to the power supply switching circuit; the power supply switching circuit is configured to convert and process the received first control signal to obtain a second control signal; the third external power supply is configured to transmit a third voltage signal to the power supply switching circuit, and the power supply switching circuit is also configured to switch and output the second voltage signal and the third voltage signal according to the second control signal, thereby realizing rapid switching between battery pack power supply and AC power supply.

The present application is provided with a DC boost circuit, a DC buck circuit, a front control circuit and a power supply switching circuit. During the day, the output end of the first external power supply (i.e., the battery pack) is connected to the DC boost circuit. If the voltage output by the first external power supply is less than the target voltage (i.e., the rated working voltage required by the load), the DC boost circuit boosts the voltage input by the first external power supply; if the voltage output by the first external power supply is greater than the target voltage, the DC boost circuit stabilizes the voltage input by the first external power supply (at this time, the voltage output by the DC boost circuit is always greater than the target voltage); the DC buck circuit bucks the first voltage signal transmitted from the DC boost circuit to obtain a second voltage signal, at this time, the relay in the second switching circuit is not energized, and the second voltage signal is directly output to the load through the second switching circuit; at night, the mains 220V is connected to the front control circuit, the optical coupling relay in the front control circuit is turned on, and then the first switching circuit in the power supply switching circuit is turned on, and then the relay in the second switching circuit is energized to work, cutting off the DC buck circuit from outputting the second voltage signal to the second switching circuit, and at the same time, the third external power supply outputs the third voltage signal to the load through the second switching circuit. It not only solves the problem of load power supply caused by floating output voltage of battery pack, but also realizes fast switching between battery power supply and AC power supply.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of an automatic transfer switch circuit in one embodiment;

FIG. 2 is a schematic diagram of a first circuit structure of an automatic transfer switch circuit in one embodiment.

Reference numerals:

1 DC boost circuit, 11 boost IC chip, 2 DC step-down circuit, 21 step-down switching regulator, 3 front control circuit, 31 rectifier circuit, 32 optocoupler relay, 33 optocoupler drive circuit, 4 power supply control circuit, 41 first switching circuit, 42 second switching circuit;

R1 is the first resistor; R2 is the second resistor; R3 is the third resistor; R4 is the fourth resistor; R5 is the fifth resistor; R6 is the sixth resistor; C1 is the first capacitor; C2 is the second capacitor; C3 is the third capacitor; C4 is the fourth capacitor; C5 is the fifth capacitor; C6 is the sixth capacitor; C7 is the seventh capacitor; C8 is the eighth capacitor; C9 is the ninth capacitor; D1 is the first diode; D2 is the second diode; D3 is the third diode; L1 is the first inductor; L2 is the second inductor.

DETAILED DESCRIPTION

In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

Example 1

As shown in FIG1 : This embodiment 1 provides an automatic transfer switch circuit, including:

A DC boost circuit 1, the DC boost circuit 1 is connected to a first external power source, and the DC boost circuit 1 is configured to convert a received first external power source signal to obtain a first voltage signal;

A DC step-down circuit 2, the DC step-down circuit 2 is connected to the DC step-up circuit 1 and the power supply switching circuit 4, and the DC step-down circuit 2 is configured to convert the received first voltage signal and transmit a second voltage signal to the power supply switching circuit 4;

A front control circuit 3, the front control circuit 3 is connected to the power supply switching circuit 4 and the second external power supply respectively, and the front control circuit 3 is configured to convert and process the received second external power supply signal and transmit the first control signal to the power supply switching circuit 4;

The power supply switching circuit 4 is respectively connected to the third external power supply, the DC step-down circuit 2, and the front control circuit 3; the power supply switching circuit 4 is configured to process the received first control signal to obtain a second control signal; the third external power supply is configured to transmit a third voltage signal to the power supply switching circuit 4, and the power supply switching circuit 4 is also configured to switch and output the second voltage signal and the third voltage signal according to the second control signal.

The voltage of the first voltage signal is always greater than DC 12V; the second voltage signal and the third voltage signal are both DC 12V.

The automatic switching switch circuit disclosed in the first aspect of the present application receives a first external power supply signal through a DC boost circuit 1, and outputs a first voltage signal to a DC step-down circuit 2. Since the first external power supply is a battery pack, its output voltage often fluctuates. When the output voltage of the battery pack is less than the target voltage, the DC boost circuit 1 performs a voltage boost process on the first external power supply signal and outputs a first voltage signal. If the output voltage of the battery pack is greater than the target voltage, the DC boost circuit 1 performs a voltage stabilization process on the first external power supply signal and outputs a first voltage signal. The DC step-down circuit 2 steps down the received first voltage signal and transmits a second voltage signal to the power supply switching circuit 4. When switching from day to night, the 220V mains voltage is connected to the front control circuit 3, the switch in the front control circuit 3 is turned on, and the first control signal is output to the power supply switching circuit 4. The power supply switching circuit 4 cuts off the current channel between the DC step-down circuit 2 and the power supply switching circuit 4 according to the first control signal, and the third external power supply outputs a third voltage signal through the power supply switching circuit to supply power to the load.

As shown in FIG. 2 , in addition to the features of the above embodiment, this embodiment further defines that: the power supply switching circuit 4 includes a first switching circuit 41 and a second switching circuit 42; the first switching circuit 41 is connected to the front control circuit 3 and the second switching circuit 42 respectively, and the second switching circuit 42 is connected to the DC step-down circuit 2;

The first switching circuit 41 is configured to convert the received first control signal and transmit the second control signal to the second switching circuit 42; the second switching circuit 42 is configured to switch and output the second voltage signal and the third voltage signal according to the second control signal.

It should be understood that the first control signal refers to whether the optocoupler relay 32 has an output voltage to the first switching circuit 41. Specifically, when the front control circuit 3 has a 220V AC power connection, the optocoupler relay 32 is turned on and can output a certain voltage to the first switching circuit 41, so that the first diode Q1 and the second diode Q2 in the first switching circuit 41 can be turned on, thereby controlling the relay coil in the second switching circuit 42 to be energized; when the front control circuit 3 does not have a 220V AC power connection, the optocoupler relay 42 is not turned on, and then the first switching circuit 41 is not turned on, and then the relay coil is not energized; the second control signal refers to whether the first switching circuit has an output voltage to the coil of the relay in the second switching circuit.

As shown in FIG2 , in addition to the features of the above embodiment, this embodiment further defines that: the first switching circuit 41 includes a first transistor Q1 and a second transistor Q2 , and the second switching circuit 42 is two sets of converted 8-pin relays;

The base of the second transistor Q2 is connected to the second output end of the pre-control circuit 3, and the first output end of the pre-control circuit 3 is connected to the collector of the first transistor Q1, the collector of the second transistor Q2, and the first pin of the second switching circuit 42; the emitter of the second transistor Q2 is connected to the base of the first transistor Q1, and the emitter of the first transistor Q1 is connected to the eighth pin of the second switching circuit 42 and the second input end of the third external power supply. The first pin of the second switching circuit 42 is connected to the sixteenth pin of the second switching circuit 42 through a coil, and the sixteenth pin of the second switching circuit 42 is connected to the ninth pin of the second switching circuit 42 and the first input end of the third external power supply. The fourth pin and the thirteenth pin of the second switching circuit 42 are respectively connected to the first output end and the second output end of the DC step-down circuit 2.

The second switching circuit 42 is two sets of switching 8-pin relays, and its model is HCP2-S-DC12V-C.

As shown in Figure 2, in addition to the features of the above-mentioned embodiment, this embodiment further defines that: the pre-control circuit 3 includes: a rectifier circuit 31, an optocoupler relay 32, and an optocoupler drive circuit 33, the input end of the rectifier circuit 31 is connected to the second external power supply, the output end of the rectifier circuit is connected to the input end of the optocoupler drive circuit 33, the output end of the optocoupler drive circuit 33 is connected to the input end of the optocoupler relay 32, and the output end of the optocoupler relay 32 is connected to the power supply switching circuit 4.

The specific model of the optocoupler driving circuit 33 is FODM3083; the specific model of the rectifier circuit 31 is MB10F.

As shown in Figure 2, in addition to the features of the above-mentioned embodiment, this embodiment further defines that: the optocoupler driving circuit 33 includes a first resistor R1, a second resistor R2, a third resistor R3, and a first diode D1; the first output end of the rectifier circuit 31 is connected to the second end of the second resistor R2, the second output end of the rectifier circuit 31 is connected to the first end of the third resistor R3, the positive electrode of the first diode D1, and the second input end of the optocoupler relay 32, the first end of the second resistor R2 is connected to the second end of the third resistor R3, the first end of the first resistor R1 and the cathode of the first diode D1, and the second end of the first resistor R1 is connected to the first input end of the optocoupler relay 32.

The first diode D1 is a voltage-stabilizing diode.

As shown in FIG2 , in addition to the features of the above embodiment, this embodiment further defines that: the DC step-down circuit 2 includes a step-down switching regulator 21 , a first capacitor C1 , a second capacitor C2 , a first inductor L1 , and a second diode D2 ;

The fifth pin of the buck switching regulator 21 is connected to the second end of the first inductor L1, the first end of the first capacitor C1, and the fourth pin of the second switching circuit 42; the third pin of the buck switching regulator 21 is connected to the positive electrode of the second diode D2, the negative electrode of the second capacitor C2, the second end of the first capacitor C1, and the thirteenth pin of the second switching circuit 42; the first end of the first inductor L1, the negative electrode of the second diode D2, and the second pin of the buck switching regulator 21 are connected to each other; the first pin of the buck switching regulator 21 is connected to the positive electrode of the second capacitor C2.

The second diode D2 is a voltage-stabilizing diode; the first capacitor C1 is a polarized capacitor.

Among them, the specific model of the step-down switching regulator 21 is LM2596R-12, its first pin is the DC voltage input terminal VIN, the second pin is the DC voltage output terminal VOUT, the third pin is the ground terminal GND, the fourth pin is the regulated sampling voltage input terminal FB, and the fifth pin is the enable control terminal OF/OFF.

As shown in FIG2 , in addition to the features of the above embodiment, the present embodiment further defines that: the DC boost circuit 1 includes a boost IC chip 11, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a third diode D3;

The first end of the third capacitor C3 is connected to the first end of the fourth capacitor C4, the first end of the fourth resistor R4, the first end of the sixth resistor R6, the cathode of the third diode D3, the seventh pin of the boost IC chip 11, the eighth pin of the boost IC chip 11, the first end of the second inductor L2, and the first input end of the DC step-down circuit 2; the second end of the third capacitor C3 is connected to the second end of the fourth capacitor C4, the second end of the fifth resistor R5, the fifth pin of the boost IC chip 11, the sixth pin of the boost IC chip 11, the second end of the sixth capacitor C6, the second end of the seventh capacitor C7, and the second end of the eighth capacitor C8 , the second end of the ninth capacitor C9, and the second input end of the DC step-down circuit 2 are connected in common; the second end of the fourth resistor R4, the first end of the fifth resistor R5, the second end of the fifth capacitor C5, and the third pin of the boost IC chip 11 are connected in common; the fourth pin of the boost IC chip 11 is connected to the first end of the seventh resistor R7, and the second end of the seventh resistor R7 is connected to the first end of the sixth capacitor C6; the second pin of the boost IC chip 11 is connected to the first end of the seventh capacitor C7, and the first pin of the boost IC chip 11 is connected in common with the second end of the second inductor L2, the first end of the eighth capacitor C8, and the first end of the ninth capacitor C9.

Among them, the third capacitor C3 and the ninth capacitor C9 are both polarized capacitors; the specific model of the boost IC chip is FP6201DR-LF, its first pin is the DC voltage input terminal VCC, the second pin is the soft start/short circuit protection SS/SCP, the third pin is the regulated voltage sampling input terminal FB, the fourth pin is the error amplifier compensation COMP, the fifth pin and the sixth pin are both the ground terminal GND, and the seventh pin and the eighth pin are both the switch external inductor terminal LX.

In addition to the features of the above embodiments, this embodiment further defines that: the first external power source is a battery pack.

It should be noted that the battery pack in this application aims to output a stable 12V voltage to power the load. Specifically, the battery pack in this application uses a lithium battery, but the output voltage of the battery pack is prone to voltage fluctuation, making it greater than 12V or less than 12V. The battery pack can be charged by solar energy or mains electricity.

In addition to the features of the above embodiments, this embodiment further defines that: the second external power supply is a 220V AC input.

In addition to the features of the above embodiments, this embodiment further defines that: the third external power source includes an inverter power circuit, and the output end of the second external power source is connected to the input end of the inverter power circuit.

The inverter power supply circuit converts the mains 220V into a DC 12V output, which is used to supply power to the load at night when the battery pack is not supplying power.

Example 2

This embodiment 2 provides an electronic device, including a load and the above-mentioned automatic transfer switch circuit, wherein the automatic transfer switch circuit is connected to the load, and the automatic transfer switch circuit supplies power to the load.

Specifically, the automatic conversion switch circuit in the above-mentioned electronic device is provided with a DC boost circuit 1, a DC buck circuit 2, a front control circuit 3 and a power supply switching circuit 4, so that when there is sufficient sunlight during the day, the output end of the first external power supply is connected to the DC boost circuit 1, and if the voltage output by the first external power supply is less than DC 12V, the DC boost circuit 1 boosts the voltage input by the first external power supply to obtain a first voltage signal greater than DC 12V; if the voltage output by the first external power supply is greater than the target voltage, the DC boost circuit 1 stabilizes the voltage input by the first external power supply; the DC buck circuit 2 stabilizes the first voltage transmitted from the DC boost circuit The signal is stepped down to obtain a second voltage signal of 12V DC. At this time, the relay in the second switching circuit 42 is not powered, and the second voltage signal is directly output to the load through the second switching circuit 42; when there is no sunlight at night, the mains 220V is connected to the front control circuit, and the optical coupling relay 32 in the front control circuit 3 is turned on, thereby turning on the first switching circuit 41 in the power supply switching circuit, and then the relay in the second switching circuit 42 is powered on, cutting off the output of the second voltage signal from the DC step-down circuit 2 to the second switching circuit 42, and at the same time, the third external power supply outputs a third voltage signal of 12V DC to the load through the second switching circuit 42. It not only solves the problem of the floating output voltage of the battery pack to power the load, but also realizes the rapid switching between battery power supply and mains power supply.

The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims (10)

1. An automatic transfer switching circuit, comprising:

The direct-current booster circuit (1), the direct-current booster circuit (1) is connected with a first external power supply, and the direct-current booster circuit (1) is configured to perform conversion processing on a received first external power supply signal to obtain a first voltage signal;

A direct current voltage reduction circuit (2), wherein the direct current voltage reduction circuit (2) is connected with the direct current voltage increase circuit (1) and the power supply switching circuit (4), and the direct current voltage reduction circuit (2) is configured to perform conversion processing on a received first voltage signal and transmit a second voltage signal to the power supply switching circuit (4);

a front-end control circuit (3), wherein the front-end control circuit (3) is respectively connected with the power supply switching circuit (4) and the second external power supply, and the front-end control circuit (3) is configured to perform conversion processing on the received second external power supply signal and transmit a first control signal to the power supply switching circuit (4);

The power supply switching circuit (4) is respectively connected with a third external power supply, the direct-current voltage reduction circuit (2) and the front control circuit (3);

The power supply switching circuit (4) is configured to perform conversion processing on the received first control signal to obtain a second control signal; the third external power supply is configured to transmit a third voltage signal to the power supply switching circuit (4), and the power supply switching circuit (4) is further configured to switch output of the second voltage signal and the third voltage signal according to the second control signal.

2. The automatic transfer switching circuit according to claim 1, wherein the power supply switching circuit (4) includes a first switching circuit (41) and a second switching circuit (42); the first switching circuit (41) is respectively connected with the front control circuit (3) and the second switching circuit (42), and the second switching circuit (42) is connected with the direct current voltage reduction circuit (2);

The first switching circuit (41) is configured to perform conversion processing on the received first control signal and to transmit a second control signal to the second switching circuit (42); the second switching circuit (42) is configured to switch output of a second voltage signal and a third voltage signal according to a second control signal.

3. The automatic transfer switching circuit of claim 2, wherein the first switching circuit (41) comprises a first transistor (Q1) and a second transistor (Q2), the second switching circuit (42) being a two-group switched 8-pin relay;

The base electrode of the second triode (Q2) is connected with the second output end of the front control circuit (3), and the first output end of the front control circuit (3) is commonly connected with the collector electrode of the first triode (Q1), the collector electrode of the second triode (Q2) and the first pin of the second switching circuit (42); the emitter of the second triode (Q2) is connected with the base of the first triode (Q1), the emitter of the first triode (Q1) is commonly connected with an eighth pin of the second switching circuit (42) and a second input end of a third external power supply, a first pin of the second switching circuit (42) is connected with a sixteenth pin of the second switching circuit (42) through a coil, the sixteenth pin of the second switching circuit (42) is commonly connected with a ninth pin of the second switching circuit (42) and a first input end of the third external power supply, and a fourth pin and a thirteenth pin of the second switching circuit (42) are respectively connected with a first output end and a second output end of the direct current voltage reduction circuit (2).

4. An automatic transfer switching circuit according to any one of claims 1-3, characterized in that the front-end control circuit (3) comprises: rectifying circuit (31), opto-coupler relay (32), opto-coupler drive circuit (33), rectifying circuit (31)'s input with second external power source is connected, rectifying circuit (31)'s output with opto-coupler drive circuit (33)'s input is connected, opto-coupler drive circuit (33) with the output with the input of opto-coupler relay (32) is connected, the output of opto-coupler relay (32) with power supply switching circuit (4) is connected.

5. The automatic transfer switching circuit according to claim 4, wherein the optocoupler driving circuit (33) includes a first resistor (R1), a second resistor (R2), a third resistor (R3), a first diode (D1); the first output end of the rectifying circuit (31) is connected with the second end of the second resistor (R2), the second output end of the rectifying circuit (31) is connected with the first end of the third resistor (R3), the anode of the first diode (D1) and the second input end of the optocoupler relay (32) in a sharing mode, the first end of the second resistor (R2) is connected with the second end of the third resistor (R3), the first end of the first resistor (R1) and the cathode of the first diode (D1) in a sharing mode, and the second end of the first resistor (R1) is connected with the first input end of the optocoupler relay (32).

6. An automatic transfer switching circuit according to claim 3, wherein the dc step-down circuit (2) comprises a step-down switching regulator (21), a first capacitor (C1), a second capacitor (C2), a first inductance (L1) and a second diode (D2);

A fifth pin of the step-down switching regulator (21) is commonly connected with the second end of the first inductor (L1), the first end of the first capacitor (C1) and a fourth pin of the second switching circuit (42); the third pin of the step-down switching regulator (21) is commonly connected with the positive electrode of the second diode (D2), the negative electrode of the second capacitor (C2), the second end of the first capacitor (C1) and the thirteenth pin of the second switching circuit (42); the first end of the first inductor (L1), the cathode of the second diode (D2) and the second pin of the buck switching regulator (21) are connected together; the first pin of the step-down switching regulator (21) is connected with the positive electrode of the second capacitor (C2).

7. The automatic transfer switching circuit according to claim 3, wherein the direct current boost circuit (1) includes a boost IC chip (11), a third capacitor (C3), a fourth capacitor (C4), a fifth capacitor (C5), a sixth capacitor (C6), a seventh capacitor (C7), an eighth capacitor (C8), a ninth capacitor (C9), a fourth resistor (R4), a fifth resistor (R5), a sixth resistor (R6), a seventh resistor (R7), and a third diode (D3);

The first end of the third capacitor (C3) is commonly connected with the first end of the fourth capacitor (C4), the first end of the fourth resistor (R4), the first end of the sixth resistor (R6), the negative electrode of the third diode (D3), the seventh pin of the boost IC chip (11), the eighth pin of the boost IC chip (11), the first end of the second inductor (L2) and the first input end of the direct current voltage reduction circuit (2); the second end of the third capacitor (C3) is commonly connected with the second end of the fourth capacitor (C4), the second end of the fifth resistor (R5), the fifth pin of the boost IC chip (11), the sixth pin of the boost IC chip (11), the second end of the sixth capacitor (C6), the second end of the seventh capacitor (C7), the second end of the eighth capacitor (C8), the second end of the ninth capacitor (C9) and the second input end of the direct current voltage reduction circuit (2); the second end of the fourth resistor (R4) is commonly connected with the first end of the fifth resistor (R5), the second end of the fifth capacitor (C5) and the third pin of the boost IC chip (11); a fourth pin of the boosting IC chip (11) is connected with the first end of the seventh resistor (R7), and the second end of the seventh resistor (R7) is connected with the first end of the sixth capacitor (C6); the second pin of the boost IC chip (11) is connected with the first end of the seventh capacitor (C7), and the first pin of the boost IC chip (11) is commonly connected with the second end of the second inductor (L2), the first end of the eighth capacitor (C8) and the first end of the ninth capacitor (C9).

8. The automatic transfer switching circuit of claim 1, wherein,

The first external power supply is a battery pack; and/or

The second external power supply is 220V input of commercial power.

9. The automatic transfer switching circuit of claim 1, wherein the third external power supply comprises an inverter power supply circuit, and wherein an output of the second external power supply is connected to an input of the inverter power supply circuit.

10. An electronic device comprising a load and an automatic transfer switching circuit according to any one of claims 1-9, wherein the automatic transfer switching circuit is connected to the load, the automatic transfer switching circuit powering the load.