A power supply switching circuit

Abstract

The utility model discloses a power supply switching circuit, which belongs to the field of power supply switching circuits; it comprises a power module M10, a DC / DC power chip U11, a field effect tube Q10, and a field effect tube Q11; the positive pole of the power module M10 is connected to the G pole of the field effect tube Q10; the first pin of the DC / DC power chip is grounded, and the second and third pin voltage output terminals are connected to the G pole of the field effect tube Q11; the S pole of the field effect tube Q11 is connected to the D pole of the field effect tube Q10. Beneficial effect: when only AC power is used for power supply, M10 converts the AC power into 12V, which is then converted into 3.6 by U11. Since the G pole voltage of Q10 is high, Q10 is turned on to supply power to the main circuit, and Q11 is cut off to prevent the power from flowing to the battery-powered part; when only the battery is used for power supply, the G pole of Q11 is low, Q11 is turned on, and Q10 is cut off to prevent the power from being transmitted to the AC power part of the circuit; when the circuit structure has both power supplies, the G pole of Q10 is at a high level, the G pole and gate of Q11 are both at high levels, and Q11 is turned off. At this time, only AC power is used for power supply, thereby achieving the purpose of saving power.

Description

Technical Field

[0001] The utility model relates to a power supply switching circuit, belonging to the field of power supply switching circuits. Background Art

[0002] At present, in general factories and residential commercial power supply and distribution systems, in order to ensure that important loads do not stop power supply (such as fire elevators, fire pumps, emergency lighting and other loads), a dual power supply mode of mains and generator is often used; mains refers to transformer power supply, and generator refers to diesel generator power supply; both mains and generator supply power to the loads on the same busbar. Under normal circumstances, the mains supplies power, but when the mains fails, it is necessary to switch to the generator equipment, which generates power to reduce the impact of the power outage; when the mains is restored, it is necessary to switch back to the mains. The traditional switching between mains and generator uses manual switching, and the distribution room needs to be staffed by a dedicated person, which will incur labor costs, and manual switching will cause the power outage interval to be too long, resulting in certain economic losses. Utility Model Content

[0003] The purpose of the utility model is to provide a power supply switching circuit, which can effectively solve the above-mentioned problems.

[0004] In order to solve the above technical problems, the utility model is achieved through the following technical solutions:

[0005] It includes a mains interface and an AC / DC conversion circuit, a DC / DC level conversion circuit, a switching and anti-reverse connection circuit, a mains working current detection circuit, and a battery working current detection circuit; the mains interface and AC / DC conversion circuit include a power module M10, the DC / DC level conversion circuit includes a DC / DC power chip U11, and the switching and anti-reverse connection circuit includes a field effect transistor Q10 and a field effect transistor Q11; the D pole of the field effect transistor Q11 is connected to the battery interface; the first pin of the DC / DC power chip is grounded, and the second pin and the third pin are connected to the G pole of the field effect transistor Q11; the positive output end of the power module M10 is connected to the G pole of the field effect transistor Q10; the S pole of the field effect transistor Q11 is connected to the D pole of the field effect transistor Q10, and the S pole of the field effect transistor Q10 is connected to the FB feedback end of the DC / DC power chip.

[0006] Furthermore: the power module M10 is connected to a varistor R14.

[0007] Further: the AC working current detection circuit is provided with a power induction power supply module U10 for detecting the AC working current; the battery working current detection circuit is provided with a power induction power supply module U11 for detecting the battery working current.

[0008] Furthermore: the AC power interface and AC / DC conversion circuit, and the switching and anti-reverse connection circuit are all provided with electrostatic and surge protection circuits; the electrostatic and surge protection circuit located in the AC power interface and AC / DC conversion circuit includes a diode D13, and the electrostatic and surge protection circuit located in the switching and anti-reverse connection circuit includes a diode D10.

[0009] Furthermore: the DC / DC level conversion circuit is also provided with a power inductor L10 and a bootstrap capacitor C12.

[0010] The beneficial effects are:

[0011] When this circuit structure is powered only by AC power, M10 converts the AC power into 12V, and then converts it into 3.6 through U11. Since the G pole voltage of Q10 is high, according to its characteristics, Q10 is turned on to supply power to the main circuit, but Q11 is turned off to prevent the power from being transmitted to the battery power supply part.

[0012] When this circuit structure is powered only by batteries, Q11G is extremely low. According to its characteristics, Q11 is turned on, V3.6 becomes the main power source, and Q10 is turned off to prevent the power from being transmitted to the mains circuit.

[0013] When both power supplies are available in this circuit structure, the G pole of Q10 is at a high level, the G pole and gate of Q11 are both at high levels, and the voltage difference is very small, causing Q11 to be turned off. At this time, only the AC power supply is used, and the battery does not participate in the power supply, thereby achieving the purpose of saving power. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] For ease of explanation, the present invention is described in detail by the following specific implementations and drawings.

[0015] Figure 1 It is the circuit principle diagram of the utility model; DETAILED DESCRIPTION

[0016] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but cannot be understood as limiting the present invention.

[0017] It should be noted that, in the description of the present invention, unless otherwise specified, "plurality" means two or more; the terms "upper", "lower", "left", "right", "inside", "outside", "front end", "rear end", "head", "tail", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0018] Furthermore, the terms “first,” “second,” “third,” etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

[0019] At the same time, in the description of the present invention, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] See also Figure 1 This is an embodiment of a power supply switching circuit of the utility model.

[0021] It includes a mains interface and AC / DC conversion circuit, a DC / DC level conversion circuit, a switching and anti-reverse connection circuit, a mains working current detection circuit, and a battery working current detection circuit; the mains interface and AC / DC conversion circuit include a power module M10, the DC / DC level conversion circuit includes a DC / DC power chip U11, and the switching and anti-reverse connection circuit includes a field effect transistor Q10 and a field effect transistor Q11; the D pole of the field effect transistor Q11 is connected to the battery interface; the first pin of the DC / DC power chip is grounded, and the second pin and the third pin are connected to the G pole of the field effect transistor Q11; the positive output end of the power module M10 is connected to the G pole of the field effect transistor Q10; the S pole of the field effect transistor Q11 is connected to the D pole of the field effect transistor Q10, and the S pole of the field effect transistor Q10 is connected to the FB feedback end of the DC / DC power chip.

[0022] When this circuit structure is powered only by AC power, M10 converts the AC power into 12V, and then converts it into 3.6 through U11. Since the G pole voltage of Q10 is high, according to its characteristics, Q10 is turned on to supply power to the main circuit, but Q11 is turned off to prevent the power from being transmitted to the battery power supply part.

[0023] When this circuit structure is powered only by batteries, Q11G is extremely low. According to its characteristics, Q11 is turned on, V3.6 becomes the main power source, and Q10 is cut off to prevent the power from being transmitted to the mains circuit.

[0024] When both power supplies are available in this circuit structure, the G pole of Q10 is at a high level, the G pole and gate of Q11 are both at high levels, and the voltage difference is very small, causing Q11 to be turned off. At this time, only the AC power supply is used, and the battery does not participate in the power supply, thereby achieving the purpose of saving power.

[0025] The power module M10 is connected with a varistor R14; the varistor R14 in this circuit structure is used for lightning protection and overvoltage protection.

[0026] A power induction power supply module U10 is provided in the mains working current detection circuit for detecting the mains working current; a power induction power supply module U11 is provided in the battery working current detection circuit for detecting the battery working current.

[0027] The power detection chips U10 and U12 detect the two power supplies respectively and transmit the signals to the MCU.

[0028] Static electricity and surge protection circuits are provided in the AC power interface and AC / DC conversion circuit, and the switching and anti-reverse connection circuit; the static electricity and surge protection circuit in the AC power interface and AC / DC conversion circuit includes a diode D13, and the static electricity and surge protection circuit in the switching and anti-reverse connection circuit includes a diode D10.

[0029] The electrostatic and surge protection circuit mainly removes the voltage stabilization and filtering performance of diode D10 and diode D13.

[0030] The DC / DC level conversion circuit is also provided with a power inductor L10 and a bootstrap capacitor C12.

[0031] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0032] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A power supply switching circuit, characterized in that: It includes a mains interface and an AC / DC conversion circuit, a DC / DC level conversion circuit, a switching and anti-reverse connection circuit, a mains working current detection circuit, and a battery working current detection circuit; the mains interface and AC / DC conversion circuit include a power module M10, the DC / DC level conversion circuit includes a DC / DC power chip U11, and the switching and anti-reverse connection circuit includes a field effect transistor Q10 and a field effect transistor Q11; the D pole of the field effect transistor Q11 is connected to the battery interface; the first pin of the DC / DC power chip is grounded, and the second pin and the third pin are connected to the G pole of the field effect transistor Q11; the positive output end of the power module M10 is connected to the G pole of the field effect transistor Q10; the S pole of the field effect transistor Q11 is connected to the D pole of the field effect transistor Q10, and the S pole of the field effect transistor Q10 is connected to the FB feedback end of the DC / DC power chip.

2. The power supply switching circuit according to claim 1, characterized in that: The power module M10 is connected to a varistor R14.

3. The power supply switching circuit according to claim 2, characterized in that: The mains operating current detection circuit is provided with a power induction power supply module U10 for detecting the mains operating current; the battery operating current detection circuit is provided with a power induction power supply module U11 for detecting the battery operating current.

4. The power supply switching circuit according to claim 3, characterized in that: The mains interface and AC / DC conversion circuit, and the switching and anti-reverse connection circuit are both provided with electrostatic and surge protection circuits; the electrostatic and surge protection circuit located in the mains interface and AC / DC conversion circuit includes a diode D13, and the electrostatic and surge protection circuit located in the switching and anti-reverse connection circuit includes a diode D10.

5. The power supply switching circuit according to claim 4, characterized in that: The DC / DC level conversion circuit is also provided with a power inductor L10 and a bootstrap capacitor C12.

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