CN216699611U

CN216699611U - Power supply switching circuit, circuit board and unmanned vending machine

Info

Publication number: CN216699611U
Application number: CN202220051352.XU
Authority: CN
Inventors: 徐达; 赵来宾
Original assignee: Hefei Midea Intelligent Technologies Co Ltd
Current assignee: Hefei Midea Intelligent Technologies Co Ltd
Priority date: 2022-01-10
Filing date: 2022-01-10
Publication date: 2022-06-07
Anticipated expiration: 2032-01-10

Abstract

The utility model provides a power supply switching circuit, a circuit board and an unmanned vending machine. The power supply switching circuit is respectively connected with a first power supply and a second power supply, and the power supply switching circuit comprises: the first control circuit is connected with the first power supply; a first switching circuit connected between the first control circuit and the second power supply; under the condition that the first power supply is in a power supply state, the first control circuit controls the first switch circuit to be in a closed state so that the second power supply is connected to the power supply switching circuit, and the first power supply supplies power to the first control circuit; and under the condition that the first power supply is in a power-off state, the second power supply supplies power to the first control circuit.

Description

Power supply switching circuit, circuit board and unmanned vending machine

Technical Field

The utility model relates to the field of electrical equipment, in particular to a power supply switching circuit, a circuit board and an unmanned vending machine.

Background

In the related art, in order to ensure that electrical equipment can smoothly complete the current work under the condition of accidental power failure of a power supply, a standby power supply is usually arranged in a circuit, when the power failure of a main power supply occurs, the standby power supply is switched into the circuit through closing a control contact, and the control scheme has switching delay in the circuit switching process, so that voltage jitter is easy to occur, impact is caused to the circuit, and the operation stability of the circuit is influenced.

SUMMERY OF THE UTILITY MODEL

The present invention is directed to solving at least one of the problems of the prior art or the related art.

To this end, a first aspect of the present invention is to provide a power switching circuit.

In a second aspect of the present invention, a circuit board is also provided.

In a third aspect of the utility model, the utility model also provides the unmanned vending machine.

In view of the above, according to a first aspect of the present invention, there is provided a power supply switching circuit, which is connected to a first power supply and a second power supply, respectively, the power supply switching circuit including: the first control circuit is connected with the first power supply; a first switching circuit connected between the first control circuit and the second power supply; under the condition that the first power supply is in a power supply state, the first control circuit controls the first switch circuit to be in a closed state so that the second power supply is connected to the power supply switching circuit, and the first power supply supplies power to the first control circuit; and under the condition that the first power supply is in a power-off state, the second power supply supplies power to the first control circuit.

In this technical scheme, a power supply switching circuit is provided, which can be respectively connected to a first power supply and a second power supply, and the power supply switching circuit specifically includes a first control circuit and a first switch circuit, where the first control circuit can be connected to the first power supply, so that the first power supply can provide electric energy for the first control circuit in a power supply state, and maintain normal operation of the first control circuit. The first switch circuit is arranged between the first control circuit and the second power supply, so that the first switch circuit can control the power supply state of the second power supply to the first control circuit, and when the first switch circuit is closed, the second power supply can supply power to the first control circuit to enable the first control circuit to maintain normal operation.

Specifically, when the circuit is powered on for the first time from a non-working state to a working state, the first power supply enters a power supply state, namely when the first power supply can output electric energy, the first control circuit acquires the electric energy output by the first power supply, the first control circuit obtains energy required by operation, the first control circuit normally operates, at the moment, the first control circuit sends a control signal to the first switch circuit to control the first switch circuit to be switched to a closed state so as to conduct a circuit between the first control circuit and the second power supply, and the second power supply can be connected into the power supply switching circuit so as to supply power to the first control circuit. When the first power supply is abnormally powered down due to some reasons, the electric energy of the second power supply is connected into the power supply switching circuit through the closed first control circuit, at the moment, due to the power failure of the first power supply, the first switching circuit does not limit the electric energy of the second power supply any more, the electric energy of the second power supply is supplied to the first control circuit through the first switching circuit, so that the first control circuit can maintain normal operation through the second power supply when the first power supply is powered down, and the operation stability of the first control circuit is ensured.

The power supply switching circuit controls the switching of the power supply, can maintain the normal operation of the circuit through the second power supply when the first power supply is abnormally powered down, improves the stability of the circuit in operation, improves the operation reliability, and because the first control circuit accesses the second power supply into the power supply switching circuit through the first switch circuit when the first power supply is abnormally powered down, the second power supply can immediately supply power to the first control circuit without any additional control and contact action when the first power supply is abnormally powered down, maintains the normal operation of the first control circuit, ensures that the process of the power supply switching circuit for switching from the power supply of the first power supply to the power supply of the second power supply is more stable, improves the smoothness of the power supply switching process, reduces the voltage jitter condition in the power supply switching process, improves the operation stability after the power supply switching, and does not contact during the switching process, the stability of power switching is prevented from being influenced by contact voltage drop, and the operation reliability and stability of the circuit are improved.

In addition, the key support in the above technical solution provided by the present invention may also have the following additional technical features:

in one aspect of the present invention, a first switch circuit includes: the first control end and the first switching end of the first relay are connected with a first power supply, and the second control end of the first relay is connected with a first control circuit; the input end of the Schottky diode is connected with the second power supply, and the output end of the Schottky diode is connected with the second switching end of the first relay; under the condition that the first power supply is in a power supply state, the first control circuit controls the first switching end and the second switching end of the first relay to be conducted so as to enable the second power supply to be connected into the power supply switching circuit, and when the voltage of the first power supply is larger than that of the second power supply, the first power supply supplies power for the first control circuit.

In the technical scheme, the second control end of the first relay coil is connected with the first control circuit, so that the first control circuit can control the coil conduction state of the first relay, and further control the opening and closing state of the first relay contact, the first control end of the first relay coil and the first switching end of the contact are connected with the first power supply, so that the first power supply can supply energy to the coil of the first relay when the first control circuit controls the first relay to be closed, the coil is electrified to generate electromagnetic force, and the contact is attracted to be pulled in. In the first switch circuit, a schottky diode is further arranged and arranged between the second power supply and the first relay, wherein the input end of the schottky diode is connected with the second power supply, so that the electric energy of the second power supply can be transmitted to the schottky diode through the input end of the schottky diode, and the output end of the schottky diode is connected with the second switching end of the contact point of the first relay, so that the electric energy transmitted to the schottky diode by the second power supply can be transmitted to the contact point of the first relay through the output end and then transmitted to the first control circuit through the contact point closed by the first relay.

Specifically, when the first power supply is in a power supply state, that is, when the first power supply can output electric energy, the first control circuit obtains energy required by operation, the first control circuit operates normally, at the moment, the first control circuit sends a control signal to the first relay, so that the electric energy of the first power supply flows into the coil through the first control end of the first relay and is transmitted to the first control circuit through the second control end, so that a closed loop is formed at two ends of the coil of the first relay, the coil of the first relay is electrified to generate electromagnetic force, a contact of the first relay acts and attracts under the attraction action of the electromagnetic force of the coil, two ends of the contact are conducted, the electric energy of the second power supply is transmitted to the second switching end of the first relay through the schottky diode and then is transmitted to the first switching end of the first relay through the closed contact, and then the electric energy of the second power supply is connected to the power supply switching circuit, when the first power supply is in power failure, the electric energy of the second power supply is supplied to the first control circuit through the switching end of the first relay, so that the first control circuit can maintain normal operation through the second power supply when the first power supply is in power failure, and the operation stability and reliability of the first control circuit are ensured.

In one aspect of the present invention, the first switch circuit further includes: and the input end of the first diode is connected with the first control circuit, and the output end of the first diode is connected with the first power supply.

In the technical scheme, a first diode is arranged in a first switch circuit, the first diode is arranged between a first control circuit and a first power supply, the input end of the first diode is connected with the first control circuit and is also connected with the second control end of a first relay, and the output end of the first diode is connected with the first power supply and is also connected with the first control end of the first relay.

In one aspect of the present invention, a first control circuit includes: a single chip microcomputer; the base electrode of the first triode is connected with the singlechip through a first resistor, the emitting electrode of the first triode is grounded, and the collecting electrode of the first triode is connected with the first switch circuit; and the second resistor is connected with the first resistor and the emitter of the first triode.

In the technical scheme, the first control circuit comprises a single chip microcomputer and a first triode, and the single chip microcomputer is used as a controller of the power supply switching circuit and is used for controlling the working state of the whole power supply switching circuit. The first control circuit also comprises a first triode, the base of the first triode is connected with the control signal output pin of the singlechip, when the first power supply is in a power supply state, namely the first power supply can output electric energy, the singlechip outputs a control signal to the base of the first triode through the signal output pin, when the base of the first triode receives the control signal output by the signal output pin of the singlechip, the collector and the emitter of the first triode are conducted, the collector of the first triode is connected with the first switch circuit, the emitter of the first triode is grounded, when the collector and the emitter of the first triode are conducted, the electric energy of the first power supply flows into the collector of the first triode through the first switch circuit and flows out of the first triode through the emitter conducted with the collector and into the ground terminal, so as to form a closed loop to conduct the first switch circuit, the first switch circuit can connect the second power supply to the power supply switching circuit, so that the second power supply supplies power to the power supply switching circuit. This application has reduced control circuit's complexity through the control circuit combination that uses singlechip and triode, has reduced control circuit's fault rate, has improved control circuit's control stability and reliability, and has reduced control circuit's cost.

In one aspect of the present invention, the power switching circuit further includes: the second control circuit is connected with the first power supply; a second switching circuit connected between the second control circuit and the second power supply; the charging circuit is connected with the second switching circuit and the second power supply; under the condition that the first power supply is in a power supply state, the second control circuit controls the second switch circuit to be in a closed state, so that the charging circuit charges the second power supply; the second control circuit controls the second switching circuit to be in an off state in a case where the first power supply is in the power-off state.

In the technical scheme, when the first power supply is in a power supply state, namely the first power supply can output electric energy, the second control circuit acquires the electric energy output by the first power supply, the second control circuit acquires energy required by operation, the second control circuit normally operates, at the moment, the second control circuit sends a control signal to the second switch circuit to control the second switch circuit to be switched to a closed state so as to conduct a circuit between the second control circuit and the charging circuit, so that the first power supply can be connected into the charging circuit, and the charging circuit can charge the second power supply through the electric energy of the first power supply. When the first power supply is in a power-off state, namely the first power supply stops outputting electric energy, the second control circuit cannot acquire the electric energy output by the first power supply, the second control circuit stops running, at the moment, the second control circuit does not send a control signal to the second switch circuit any more, the second switch circuit is switched to a disconnected state, the connection between the first power supply and the charging circuit is disconnected, the charging circuit cannot acquire the electric energy of the first power supply, and the charging circuit stops charging the second power supply.

The second control circuit is used for controlling the second switch circuit, and the on-off state of the first power supply and the charging circuit is controlled through the on-off state of the second switch circuit, so that when the first power supply is in a power supply state, the second control circuit can control the charging circuit to charge the second power supply through the first power supply, the electric quantity of the second power supply is maintained sufficient, the second power supply can have sufficient backup electric quantity to maintain the operation of the circuit when the first power supply is powered off, the power supply stability and reliability of the second power supply are improved, and the stability and reliability of the circuit during operation are improved. And after the first power supply stops supplying power, the second switch circuit can disconnect the connection between the charging circuit and the second control circuit, so that the phenomenon that after the charging is stopped, the second power supply leaks current to the second control circuit through the second switch circuit to cause the electric quantity of the second power supply to be lost and influence the electric energy storage of the second power supply is avoided, and by disconnecting the second switch circuit, the electric energy storage reliability of the second power supply is improved, the leakage current is reduced, the electric energy waste is reduced, and the use reliability of the second power supply is improved.

In one aspect of the present invention, the second control circuit includes: the base electrode of the second triode is connected with the singlechip through a third resistor, and the emitting electrode of the second triode is grounded; and the fourth resistor is connected with the third resistor and the emitting electrode of the second triode.

In the technical scheme, the second control circuit comprises a second triode, the base of the second triode is connected with a control signal output pin of the singlechip, when the first power supply is in a power supply state, namely the first power supply can output electric energy, the singlechip outputs a control signal to the base of the second triode through the signal output pin, when the base of the second triode receives the control signal output by the signal output pin of the singlechip, the collector and the emitter of the second triode are conducted, the collector of the second triode is connected with a second switching circuit, the emitter of the second triode is grounded, when the collector and the emitter of the second triode are conducted, the electric energy of the first power supply flows into the collector of the second triode through the second switching circuit and flows out of the second triode through the emitter which is conducted with the collector and flows into the ground terminal, therefore, a closed loop is formed to conduct the second switch circuit, so that the second switch circuit can connect the first power supply into the charging circuit, and the charging circuit charges the second power supply through the first power supply. This application has reduced control circuit's complexity through the control circuit combination that uses singlechip and triode, has reduced control circuit's fault rate, has improved control circuit's control stability and reliability, and has reduced control circuit's cost.

In one aspect of the present invention, the second switch circuit includes: the first control end and the first switching end of the second relay are connected with the first power supply, the second control end of the second relay is connected with the second control circuit, and the second switching end of the second relay is connected with the charging circuit; and the input end of the second diode is connected with the second control circuit, and the output end of the second diode is connected with the first power supply.

In the technical scheme, the second control end of the second relay coil is connected with the second control circuit, so that the second control circuit can control the coil conduction state of the second relay, and further control the opening and closing state of the second relay contact, the first control end of the second relay coil and the first switching end of the contact are connected with the first power supply, so that the first power supply can supply energy to the coil of the second relay when the second control circuit controls the second relay to be closed, the coil is electrified to generate electromagnetic force, and the contact is attracted to be pulled in.

Specifically, when the first power supply is in a power supply state, that is, the first power supply can output electric energy, the second control circuit obtains energy required by operation, the second control circuit operates normally, at the moment, the second control circuit sends a control signal to the second relay, so that the electric energy of the first power supply flows into the coil through the first control end of the second relay and is transmitted to the second control circuit through the second control end, so that a closed loop is formed at two ends of the coil of the second relay, the coil of the second relay is electrified to generate electromagnetic force, the contact of the second relay acts and attracts under the attraction action of the electromagnetic force of the coil, two ends of the contact are conducted, the electric energy of the first power supply is transmitted to the charging circuit through the closed contact, the charging circuit charges the second power supply, further, the second power supply is charged through the first power supply, and the convenience of charging control is improved, the stability of charging is improved. And after the first power supply stops supplying power, the charging circuit can be disconnected from the second control circuit rapidly, the electric quantity loss of the second power supply is reduced, the electric energy storage reliability of the second power supply is improved, the leakage current is reduced, the electric energy waste is reduced, and the use reliability of the second power supply is improved.

In one aspect of the present invention, a charging circuit includes: the charging detection circuit is connected with the second switch circuit and the second power supply and is used for acquiring the charging state of the second power supply; and the charging control circuit is connected with the charging detection circuit and the second power supply and is used for controlling the charging state of the second power supply.

In the technical scheme, the charging circuit specifically comprises a charging detection circuit, the charging detection circuit is connected with the second power supply, and the specific charging state of the second power supply in the charging process can be acquired through the charging detection circuit; the charging circuit further comprises a charging control circuit, the charging control circuit is connected with the charging detection circuit and is connected with the second power supply, and the charging control circuit can adjust and control the charging state of the second power supply according to the charging state of the second power supply acquired by the charging detection circuit. Through setting up the detection circuitry that charges in charging circuit, make charging circuit can acquire the specific charging state of second power in charging process, make the charging control circuit can control and adjust according to the charging state who acquires, improve the charge stability of second power, improve charge efficiency, reduce the charge time.

In one aspect of the present invention, a charge detection circuit includes: the current detection resistor is connected with the second power supply and used for acquiring charging current; one end of the divider resistor is connected with the second power supply, the other end of the divider resistor is grounded through a fifth resistor, and the divider resistor is used for acquiring charging voltage;

in the technical scheme, the charging detection circuit specifically comprises a current detection resistor, the current detection resistor is connected with a second power supply, the charging current of the second power supply in the charging process of the charging circuit can be obtained by connecting the current detection resistor with the second power supply, and the current charging state of the second power supply can be obtained by the charging current; the voltage divider resistor is connected with the second power supply, the other end of the voltage divider resistor is grounded through a fifth resistor, the voltage divider resistor can be connected with the second power supply in series for voltage division, the voltage of the second power supply is obtained in an equal proportion mode through series voltage division, the equal proportion second power supply voltage with lower voltage is obtained, and the current charging state of the second power supply can be obtained through the obtained charging voltage. The charging detection circuit is formed by the current detection resistor and the divider resistor, the structure of the charging detection circuit is simplified, the circuit complexity of the charging detection circuit is reduced, the circuit failure rate is reduced, the detection efficiency is improved, in addition, the fifth resistor is arranged between the divider resistor and the ground, the leakage current of the second power supply through the divider resistor grounding end is reduced, the electric quantity loss of the second power supply is reduced, the electric energy storage reliability of the second power supply is improved, the leakage current is reduced, the electric energy waste is reduced, and the use reliability of the second power supply is improved.

In one aspect of the present invention, a charge control circuit includes; the drain electrode of the transistor is connected with a second power supply, and the source electrode of the transistor is grounded; and a first pin and a third pin of the charging controller are respectively connected with two ends of the current detection resistor, a second pin of the charging controller is connected with the divider resistor, a fifth pin of the charging controller is connected with a grid electrode of the transistor, a sixth pin of the charging controller is grounded, and the charging controller is used for controlling the charging state of the second power supply according to the charging current and the charging voltage.

In this embodiment, the charge control circuit is provided with a transistor, a drain of the transistor is connected to the second power supply, and a source of the transistor is grounded. The charging control circuit comprises a charging controller, the charging controller is connected with two ends of a current detection resistor through a first pin and a third pin, so that the charging current of a second power supply is obtained through the current detection resistor, the charging controller is connected with a divider resistor through a second pin, so that the charging voltage of the second power supply is obtained through the divider resistor, the charging controller is connected with a grid electrode of a transistor through a fifth pin, the on-off state of the transistor is controlled in a mode of transmitting a control signal to the grid electrode of the transistor, and the charging state of the second power supply is controlled by controlling the on-off state of the transistor.

Through setting up the charge controller to be connected with charge detection circuit's current detection resistance and divider resistance, make the charge controller can control the transistor according to the charging current and the charging voltage who acquire, can control the charged state of second power through the control to the transistor, simplified the charge control circuit, reduced the complexity of charge control circuit, reduced the circuit fault rate, improved charge efficiency.

In one aspect of the present invention, the charging circuit further includes: the inductor is connected with the current detection resistor and the second power supply and used for providing inductor current; and the cathode of the first voltage-stabilizing tube is connected with the inductor, and the anode of the first voltage-stabilizing tube is connected with the second power supply.

In the technical scheme, an inductor is arranged in the charging circuit, one end of the inductor is connected with the current detection resistor, and the other end of the inductor is connected with the second power supply and the drain electrode of the transistor and used for passing through the inductor current required by charging. When the charging circuit is connected with a first power supply, the charging controller controls the transistor to be conducted, the inductive current rises, the inductive current begins to be accumulated in the inductor, when the inductive current rises to the upper limit set by the current detection resistor, the charging controller controls the transistor to be turned off, at the moment, the inductive current drops, the energy in the inductor is transferred to a second power supply, when the inductive current drops to the lower limit set by the current detection resistor, the charging controller controls the transistor to be conducted again, the cycle is repeated, until the voltage of the divider resistor obtained by the charging controller reaches the upper limit of the preset voltage, the charging process is finished, the charging controller controls the transistor to be kept in the off state, the charging circuit finishes charging the second power supply, when the voltage of the divider resistor obtained drops to the lower limit of the preset voltage, the charging circuit enters the charging state again, and the charging step is repeatedly executed, the second power supply is charged again.

The transistor is used for controlling the inductive current to charge the second power supply, so that the charging voltage can be improved, the voltage drop of the charging circuit is reduced, the charging voltage of the second power supply is improved, the charging electric quantity of the second power supply is further improved, the capacity utilization rate of the second power supply is improved, the electric energy reserve is improved, and the charging efficiency is improved.

In one aspect of the present invention, the charging circuit further includes: one end of the first capacitor is connected with the current detection resistor, and the other end of the first capacitor is grounded; one end of the second capacitor is connected with the fourth pin of the charge controller, and the other end of the second capacitor is grounded; and one end of the third capacitor is connected with the second power supply, and the other end of the third capacitor is grounded.

In the technical scheme, the charging circuit is further provided with a first capacitor, one end of the first capacitor is connected with the current detection resistor, the other end of the first capacitor is grounded, and the first capacitor is arranged at the current detection resistor, so that the influence of first power supply voltage fluctuation on the detection precision of the current detection resistor can be reduced, the noise interference of the circuit is reduced, the detection precision of the current detection resistor is improved, and the charging efficiency of the charging circuit is improved.

The charging circuit is also provided with a second capacitor, one end of the second capacitor is connected with a fourth pin of the charging controller, the other end of the second capacitor is grounded, the fourth pin of the charging controller can be emptied by arranging the second capacitor at the fourth pin of the charging controller, the influence of a 5V (volt) power supply at the fourth pin on the charging circuit is reduced, the noise interference of the circuit is reduced, the control accuracy of the charging controller is improved, and the charging efficiency of the charging circuit is improved.

The charging circuit is also provided with a third capacitor, one end of the third capacitor is connected with the second power supply, the other end of the third capacitor is grounded, and the third capacitor is arranged at the second power supply, so that the influence of the voltage fluctuation of the second power supply on the charging process of the charging circuit can be reduced, the noise interference of the charging circuit is reduced, and the charging efficiency of the charging circuit is improved.

In one aspect of the present invention, the power switching circuit further includes: the detection circuit is connected with the mains supply and the first control circuit and comprises a rectification circuit and a signal processing circuit; the rectification circuit is connected with a mains supply and is used for rectifying current output by the mains supply; the signal processing circuit is connected with the rectifying circuit and can determine that the first power supply is in a power supply state or a power failure state according to the current processed by the rectifying circuit.

In this technical solution, the power switching circuit further includes a detection circuit, the detection circuit is connected to the commercial power supply and the first control circuit, and the detection circuit includes a rectification circuit and a signal processing circuit. The rectifying circuit is connected with a mains supply, and can rectify the obtained mains supply current to convert the alternating current of the mains supply into a direct current power supply and supply the direct current power supply to the signal processing circuit, so that the current processing of the signal processing circuit is facilitated. The signal processing circuit is connected with the rectifying circuit, and whether the first power supply is in a power supply state or a power failure state can be determined through current output by the rectifying circuit.

By arranging the detection circuit, the power supply state of the first power supply can be identified, whether the first power supply supplies power normally or not is determined, the controller can control the circuit according to the power supply state of the first power supply, the identification accuracy of the power supply state of the first power supply is improved, the complexity of the power supply state identification circuit is reduced, the identification efficiency is improved, the current is used as the basis for checking the power supply state, the influence of voltage fluctuation on the detection precision can be reduced, the misjudgment of a detection result is avoided, and the detection precision is improved.

In one aspect of the present invention, a signal processing circuit includes: the anode of the second voltage-stabilizing tube is connected with the anode of the rectifying circuit, and the cathode of the second voltage-stabilizing tube is connected with the cathode of the rectifying circuit; the fourth capacitor is connected in parallel with the second voltage-regulator tube; and the third power supply is connected with the anode of the second voltage-regulator tube.

In the technical scheme, the signal processing circuit specifically comprises a second voltage-stabilizing tube, wherein the anode of the second voltage-stabilizing tube is connected with the anode of the rectifying circuit, the cathode of the second voltage-stabilizing tube is connected with the cathode of the rectifying circuit, and the voltage-stabilizing tube is arranged between the anode and the cathode of the rectifying circuit, so that the voltage-stabilizing tube can stabilize the current output by the rectifying circuit, the influence of the output voltage on the detection precision is reduced, and the detection accuracy is improved; the fourth capacitor is connected with the second voltage regulator tube in parallel, and the capacitor is arranged in the signal processing circuit, so that the noise interference of the output current of the rectifying circuit can be reduced, the influence of the noise interference on the detection precision is reduced, and the detection accuracy is improved.

In one aspect of the present invention, the signal processing circuit further includes: the photoelectric switch is connected with the rectifying circuit through a sixth resistor; the negative electrode of the light receiving end of the photoelectric switch is grounded, and the positive electrode of the light receiving end of the photoelectric switch is connected with the detection power supply through the seventh resistor.

In the technical scheme, the signal processing circuit further comprises a photoelectric switch, the photoelectric switch is connected with the rectifying circuit through a sixth resistor and used for obtaining current output by the rectifying circuit and determining the power supply state of the first power supply according to the current, the anode of the light receiving end of the photoelectric switch is connected with the detection power supply through a seventh resistor, and the cathode of the light receiving end is grounded. When the rectifying circuit outputs current, the current flows in from the positive pole connected with the rectifying circuit and flows out from the negative pole, the light emitting diode in the photoelectric switch is lightened in the process, after the light emitting diode is lightened, the light receiving end is conducted, the current of the detection power supply flows in through the positive pole of the light receiving end and flows out from the negative pole, the detection current is generated, the flowing state of the current of the detection power supply can be controlled by controlling the conducting state of the light receiving end, and whether the first power supply is in the power supply state or not is determined. The structure complexity of the signal processing circuit is reduced, the circuit fault rate is reduced, the detection reliability is improved, the influence of voltage fluctuation on the detection precision can be reduced by detecting through the current, the misjudgment of the detection result is avoided, and the detection precision is improved.

In a second aspect of the present invention, there is provided a circuit board including the power switching circuit according to any one of the above technical solutions.

In this technical solution, a circuit board is provided, where the circuit board includes the power switching circuit according to any one of the above technical solutions, so that all the beneficial effects of the power switching circuit are achieved, and details are not described herein.

In a third aspect of the utility model, there is provided an unmanned vending machine comprising a circuit board as in the above technical solution.

In this technical solution, a vending machine is provided, which includes the circuit board according to the above technical solution, so that the vending machine has all the beneficial effects of the circuit board, and details are not repeated herein.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a schematic diagram of a power switching circuit according to an embodiment of the utility model;

FIG. 2 is a schematic diagram showing a detailed structure of a power switching circuit according to an embodiment of the utility model;

FIG. 3 shows one of the schematic structural diagrams of the charging circuit in an embodiment of the utility model;

FIG. 4 is a second schematic diagram of a charging circuit according to an embodiment of the utility model;

FIG. 5 is a schematic diagram showing a specific structure of a charging circuit according to an embodiment of the present invention;

FIG. 6 shows a schematic diagram of a detection circuit in an embodiment of the utility model;

FIG. 7 is a schematic diagram showing the detailed structure of the detection circuit in one embodiment of the present invention;

wherein, the correspondence between the reference numbers and the part names in fig. 1 to 7 is:

the circuit comprises a K1 first relay, a D1 first diode, a D2 Schottky diode, a Q1 first triode, a R1 first resistor, a R2 second resistor, a Q2 second triode, a R3 third resistor, a R4 fourth resistor, a K2 second relay, a D3 second diode, a R5 current detection resistor, a R6 voltage division resistor, a R7 fifth resistor, a Q3 transistor, a U1 charging controller, a L1 inductor, a D4 first voltage regulator, a C1 first capacitor, a C2 second capacitor, a C3 third capacitor, a U2 rectifier bridge, a D5 second voltage regulator, a C4 fourth capacitor, a U3 photoelectric switch, a R8 sixth resistor and a R9 seventh resistor.

Detailed Description

So that the manner in which the above recited aspects, features and advantages of the present invention can be understood in detail, a more particular description of the utility model, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It should be noted that the embodiments of the present invention and features of the embodiments may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

A power switching circuit, a circuit board, and an unmanned aerial vehicle proposed according to some embodiments of the present invention are described below with reference to fig. 1 to 7.

As shown in fig. 1, according to a first aspect of the present invention, there is provided a power supply switching circuit, which is connected to a first power supply and a second power supply, respectively, the power supply switching circuit including: the first control circuit is connected with the first power supply; a first switching circuit connected between the first control circuit and the second power supply; under the condition that the first power supply is in a power supply state, the first control circuit controls the first switch circuit to be in a closed state so that the second power supply is connected to the power supply switching circuit, and the first power supply supplies power to the first control circuit; and under the condition that the first power supply is in a power-off state, the second power supply supplies power to the first control circuit.

In this embodiment, a power switching circuit is provided, the power switching circuit can be respectively connected to a first power source and a second power source, and the power switching circuit may specifically include a first control circuit and a first switch circuit, where the first control circuit can be connected to the first power source, so that the first power source can provide electric energy for the first control circuit in a power supply state, and maintain normal operation of the first control circuit. And a first switch circuit is arranged between the first control circuit and the second power supply, the first switch circuit is arranged between the first control circuit and the second power supply, so that the first switch circuit can control the second power supply and control the power supply state when the first control circuit is powered on, and when the first switch circuit is closed, the second power supply can supply power to the first control circuit, so that the first control circuit can maintain normal operation.

Specifically, when the circuit is powered on for the first time from a non-working state to a working state, the first power supply enters a power supply state, namely when the first power supply can output electric energy, the first control circuit acquires the electric energy output by the first power supply, the first control circuit obtains energy required by operation, the first control circuit normally operates, at the moment, the first control circuit sends a control signal to the first switch circuit to control the first switch circuit to be switched to a closed state so as to conduct a circuit between the first control circuit and the second power supply, and the second power supply can be connected into the power supply switching circuit so as to supply power to the first control circuit. When the first power supply is abnormally powered down due to some reasons, the electric energy of the second power supply is connected into the power supply switching circuit through the closed first control circuit, at the moment, the first switch circuit does not limit the electric energy of the second power supply any more due to the power failure of the first power supply, and the electric energy of the second power supply is supplied to the first control circuit through the first switch circuit, so that the first control circuit can maintain normal operation through the second power supply when the first power supply is powered down, and the operation stability of the first control circuit is ensured.

Further, the first power can be for exchanging the low pressure DC power supply that mains supply obtained after step-down and rectification, through using exchanging mains supply for the energy supply of first power, it is more convenient, more stable to make the energy of first power acquire, reduces the complexity of first power supply circuit, reduces the cost that first power was acquireed at the energy, improves the energy supply convenience and the stability of first power.

Further, the second power can be lithium battery power, through using the lithium cell as the second power, can improve the convenience of second power when deploying, can improve the energy supply reliability of second power simultaneously, and then promote power switching circuit's operational reliability, guarantee that the back second power of power switching can stabilize the energy supply, improve equipment operational stability and reliability.

The present embodiment provides a power supply switching circuit, and in addition to the technical features of the above embodiments, the present embodiment further includes the following technical features.

As shown in fig. 2, the first switch circuit in the power switching circuit provided in the present embodiment includes a first relay K1 and a schottky diode. The first control end and the first switching end of the first relay K1 are connected with a first power supply, the second control end of the first relay K1 is connected with a first control circuit, and the second switching end of the first relay K1 is connected with a second power supply; the input end of the Schottky diode D2 is connected with a second power supply, and the output end of the Schottky diode is connected with the second switching end of the first relay K1; under the condition that the first power supply is in a power supply state, the first control circuit controls the first switching end and the second switching end of the first relay K1 to be conducted so as to enable the second power supply to be connected into the power supply switching circuit, and the first power supply supplies power to the first control circuit based on the fact that the voltage of the first power supply is larger than that of the second power supply; in a state where the second power supply is in a power supply end state, the first control circuit controls the first switching terminal and the second switching terminal of the first relay K1 to be disconnected.

In this embodiment, in the first switch circuit, a first relay K1 is provided, and the first relay K1 includes a first control terminal, a second control terminal, a first switch terminal and a second switch terminal, wherein two ends of a coil of the first relay K1 correspond to the first control terminal and the second control terminal respectively, and a power supply loop is formed between the first control terminal and the second control terminal, so that the coil is electrified to generate an electromagnetic force, and the attraction contact is attracted to pull in, thereby conducting two ends of the contact. Two ends of a contact of the first relay K1 are respectively corresponding to a first switching end and a second switching end, and the electromagnetic force generated by electrifying the coil attracts the contact to attract, so that the two ends of the contact can be conducted, and the first switching end and the second switching end are conducted.

Specifically, the second control end of the coil of the first relay K1 can be connected with the first control circuit, so that the first control circuit can control the coil conducting state of the first relay K1, and further control the opening and closing state of the contact of the first relay K1, the first control end and the first switching end of the first relay K1 are connected with the first power supply, so that the first power supply can control the first relay K1 at the first control circuit, and the coil of the first relay K1 is powered when the first relay K1 is closed, so that the coil is powered to generate electromagnetic force, and the attraction contact is attracted. In the first switch circuit, a schottky diode D2 is further provided, the schottky diode D2 is provided between the second power source and the first relay K1, wherein an input terminal of the schottky diode D2 is connectable to the second power source so that the electric power outputted from the second power source can be transmitted to the schottky diode D2 through the input terminal of the schottky diode D2, and an output terminal of the schottky diode D2 is connectable to the second switching terminal of the contact of the first relay K1 so that the electric power transmitted from the second power source to the schottky diode D2 can be transmitted to the contact of the first relay K1 through the output terminal and then to the first control circuit via the contact closed by the first relay K1.

Specifically, when the operating condition of first power is in the power supply state, when first power can output the electric energy promptly, first control circuit obtains the required energy of operation, first control circuit normal operating, at this moment, first control circuit control first relay K1's contact closure, and then insert the electric energy of second power into power supply switching circuit, when the power failure of first power, the electric energy of second power will supply for first control circuit through the switching end of first relay K1, so that first control circuit can keep normal operating through the second power when the power failure of first power, guarantee first control circuit's operational stability and reliability.

In addition, because the schottky diode D2 is arranged between the second power supply and the first relay K1, when the contact of the first relay K1 is closed, the first power supply is conducted with the second power supply, and because the voltage of the first power supply is slightly higher than that of the second power supply, the electric energy of the second power supply is limited in the schottky diode D2 by the electric energy of the first power supply, and the electric energy of the second power supply cannot be transmitted to the first control circuit, so that the situation that the electric energy storage of the second power supply is reduced due to the fact that the second power supply supplies power simultaneously when the first power supply supplies power is avoided, the power supply stability of the second power supply when the first power supply is powered off is influenced, and the operation stability and reliability of the power supply switching circuit when the first power supply is powered off are improved. When the first power supply is powered down, the first power supply relieves the limitation on the second power supply in the Schottky diode D2, the second power supply supplies power to the first control circuit through the Schottky diode D2, and the power supply of the second power supply is controlled without any additional control and contact action, so that the process of switching the power supply of the power supply switching circuit to the power supply of the second power supply through the first power supply is more stable, the smoothness of the power supply switching process is improved, the voltage jitter condition in the power supply switching process is reduced, the operation stability after the power supply switching is improved, and the non-contact action in the switching process avoids generating a voltage drop to influence the stability of the power supply switching, and the operation reliability and the stability of the circuit are improved.

In addition, the Schottky diode D2 is arranged between the second power supply and the first power supply, so that after the first power supply is conducted with the second power supply, the Schottky diode D2 can stop the current of the first power supply, the current of the first power supply is prevented from reversely flowing into the second power supply to damage the second power supply, the operation safety of the second power supply is improved, and the operation life of the second power supply is prolonged.

As shown in fig. 2, the first switch circuit in the power switching circuit provided in this embodiment further includes a first diode D1. The input terminal of the first diode D1 is connected to the first control circuit, and the output terminal of the first diode D1 is connected to the first power source.

In this embodiment, a first diode D1 is provided in the first switch circuit, and the first diode D1 is provided between the first control circuit and the first power source, and the input terminal of the first diode D1 can be connected to the first control circuit, and can also be connected to the second control terminal included in the first relay K1, and the output terminal of the first diode D1 can be connected to the first power source, and can also be connected to the first control terminal of the first relay K1. Through setting up first diode D1 and the coil of first relay K1 is parallelly connected, makes first diode D1 can absorb the back electromotive force that first relay K1's coil produced in the twinkling of an eye at circular telegram and outage, reduces the impact of back electromotive force to circuit and power, reduces the interference to first power, the stability of protection first power.

As shown in fig. 2, the first control circuit in the power switching circuit provided in this embodiment includes a single chip, a first transistor Q1, and a second resistor R2. The base electrode of the first triode Q1 is connected with the singlechip through a first resistor R1, the emitting electrode of the first triode is grounded, and the collecting electrode of the first triode is connected with a first switch circuit; the second resistor R2 is connected to the first resistor R1 and the emitter of the first transistor Q1.

In an embodiment, the first control circuit includes a single chip microcomputer and a first transistor Q1, the single chip microcomputer controls conduction between a collector and an emitter of the first transistor Q1 by sending a control signal to a base of the first transistor Q1, when conduction is established between the collector and the emitter of the first transistor Q1, electric energy of the first power supply flows into the collector of the first transistor Q1 through the first switch circuit, and flows out of the first transistor Q1 through the emitter which is in conduction with the collector and flows into a ground terminal, so as to form a closed loop to conduct the first switch circuit, so that the first switch circuit can connect the second power supply into the power supply switching circuit, thereby realizing power supply of the second power supply to the power supply switching circuit. This application has reduced control circuit's complexity through the control circuit combination that uses singlechip and triode, has reduced control circuit's fault rate, has improved control circuit's control stability and reliability, and has reduced control circuit's cost.

And, through setting up first resistance R1 between the base of singlechip and first triode Q1, make first resistance R1 can carry out the current-limiting to the control current of singlechip output, reduce the singlechip and to the electric current that the base of first triode Q1 sent, avoid the base of first triode Q1 to damage because of the overcurrent, the operation safety of protection first triode Q1, and divide the partial pressure to the control signal of telecommunication of singlechip output through first resistance R1, reduce the voltage of the control signal that first triode Q1 base received, reduce the probability that first triode Q1 base causes the damage because of the excessive pressure, improve the stability and the reliability of triode control, extension triode life.

As shown in fig. 3, the power switching circuit provided in this embodiment further includes: the second control circuit is connected with the first power supply; a second switching circuit connected between the second control circuit and the second power supply; the charging circuit is connected with the second control circuit and the second power supply; under the condition that the first power supply is in a power supply state, the second control circuit controls the second switch circuit to be in a closed state, so that the charging circuit charges the second power supply; the second control circuit controls the second switching circuit to be in an off state in a case where the first power supply is in the power-off state.

In this embodiment, the power switching circuit further includes a second control circuit and a second switch circuit, where the second control circuit can be connected to the first power supply, so that the first power supply can provide power for the second control circuit in a power supply state, and maintain normal operation of the second control circuit. And a second switch circuit is arranged between the second control circuit and the second power supply, and the second switch circuit is arranged between the second control circuit and the second power supply, so that the second switch circuit can control the connection state of the first power supply and the second power supply. And a charging circuit is arranged between the second switch circuit and the second power supply, and the charging circuit is arranged between the second switch circuit and the second power supply, so that the charging circuit can charge the second power supply through the first power supply when the working state of the second switch circuit is in a closed state, and the electric quantity of the second power supply is sufficient.

Specifically, when the working state of the first power supply is in a power supply state, that is, the first power supply can output electric energy, the second control circuit acquires the electric energy output by the first power supply, the second control circuit acquires energy required by operation, the second control circuit operates normally, at this time, the second control circuit sends a control signal to the second switch circuit to control the second switch circuit to switch to a closed state, so as to conduct a circuit between the second control circuit and the charging circuit, so that the first power supply can be connected into the charging circuit, and the charging circuit can charge the second power supply through the electric energy of the first power supply. When the working state of the first power supply is in a power-off state, namely the first power supply stops outputting electric energy, the second control circuit cannot acquire the electric energy output by the first power supply, the second control circuit stops running, at the moment, the second control circuit does not send a control signal to the second switch circuit any more, the second switch circuit is switched to a disconnected state, the connection between the first power supply and the charging circuit is disconnected, the charging circuit cannot acquire the electric energy of the first power supply, and the charging circuit stops charging the second power supply.

The second control circuit is used for controlling the second switch circuit, and the on-off state of the first power supply and the charging circuit is controlled through the on-off state of the second switch circuit, so that when the working state of the first power supply is in a power supply state, the second control circuit can control the charging circuit to charge the second power supply through the first power supply, the electric quantity of the second power supply is maintained sufficient, the second power supply can have sufficient backup electric quantity to maintain the operation of the circuit when the first power supply is powered off, the power supply stability and reliability of the second power supply are improved, and the stability and reliability of the circuit during operation are improved. And after the first power supply stops supplying power, the second switch circuit can disconnect the connection between the charging circuit and the second control circuit, so that the phenomenon that after the charging is stopped, the second power supply leaks current to the second control circuit through the second switch circuit to cause the electric quantity of the second power supply to be lost and influence the electric energy storage of the second power supply is avoided, and by disconnecting the second switch circuit, the electric energy storage reliability of the second power supply is improved, the leakage current is reduced, the electric energy waste is reduced, and the use reliability of the second power supply is improved.

As shown in fig. 4, the second control circuit in the power switching circuit provided in this embodiment includes a second transistor Q2, a single chip microcomputer, and a fourth resistor R4, wherein a base of the second transistor Q2 is connected to the single chip microcomputer through a third resistor R3, and an emitter of the second transistor Q2 is grounded; the fourth resistor R4 is connected to the third resistor R3 and the emitter of the second transistor.

In this embodiment, the second control circuit includes a second transistor Q2, when the first power supply is in a power supply state, that is, the first power supply can output power, the single chip sends a control signal to the base of the second transistor Q2 to control conduction between the collector and the emitter of the second transistor Q2, and when the collector and the emitter of the second transistor Q2 are conducted, the power of the first power supply flows into the collector of the second transistor Q2 through the second switch circuit, and flows out of the second transistor Q2 through the emitter conducted with the collector and into the ground, so as to form a closed loop to conduct the second switch circuit, so that the second switch circuit can connect the first power supply into the charging circuit, and the charging circuit charges the second power supply through the first power supply. This application has reduced control circuit's complexity through the control circuit combination that uses singlechip and triode, has reduced control circuit's fault rate, has improved control circuit's control stability and reliability, and has reduced control circuit's cost.

And, through setting up the third resistance R3 between the base of singlechip and second triode Q2, make the control current that third resistance R3 can be exported to the singlechip carry out the current-limiting, reduce the singlechip to the electric current that the base of first triode Q1 sent, avoid the base of first triode Q1 to damage because of the overcurrent, the operation safety of protection first triode Q1, and divide the partial pressure to the control signal of telecommunication of singlechip output through third resistance R3, reduce the voltage of the control signal that the base of second triode Q2 received, reduce the probability that the base of second triode Q2 causes the damage because of the overvoltage, improve the stability and the reliability of triode control, extension triode life.

As shown in fig. 4, the second switch circuit in the power switching circuit provided by the present embodiment includes a second relay K2 and a second diode D3. The first control end and the first switching end of the second relay K2 are connected with a first power supply, and the second control end of the second relay K2 is connected with a second control circuit; the input end of the second diode D3 is connected to the second control circuit, and the output end of the second diode is connected to the first power supply.

In this embodiment, in the second switch circuit, a second relay K2 is provided, and the second relay K2 includes a first control terminal, a second control terminal, a first switch terminal and a second switch terminal, wherein two ends of a coil of the second relay K2 are respectively corresponding to the first control terminal and the second control terminal, and a power supply loop is formed between the first control terminal and the second control terminal, so that the coil is electrified to generate an electromagnetic force, and the attraction contact is attracted to close, thereby conducting two ends of the contact. Two ends of a contact of the second relay K2 are respectively corresponding to a first switching end and a second switching end, and the two ends of the contact can be conducted by attracting the contact through electromagnetic force generated by electrifying the coil so as to enable the two ends of the contact to be conducted, thereby conducting the first switching end and the second switching end.

Specifically, the second control end of the coil of the second relay K2 is connected with the second control circuit, so that the second control circuit can control the coil conducting state of the second relay K2, and further control the opening and closing state of the contact of the second relay K2, the first control end of the coil of the second relay K2 is connected with the first switching end of the contact and the first power supply, so that the first power supply can supply energy to the coil of the second relay K2 when the second control circuit controls the second relay K2, and the second relay K2 is controlled to be closed, so that the coil is electrified to generate electromagnetic force, and the contact is attracted to pull in.

Specifically, when the working state of the first power supply is in a power supply state, that is, the first power supply can output electric energy, the second control circuit obtains energy required by operation, the second control circuit operates normally, at this time, the second control circuit sends a control signal to the second relay K2 to control the second relay K2, so that the electric energy output by the first power supply can flow into the coil through the first control end included in the second relay K2 and is transmitted to the second control circuit through the second control end, so that a closed loop is formed at two ends of the coil of the second relay K2, the coil of the second relay K2 is electrified to generate electromagnetic force, the contact of the second relay K2 acts and attracts under the attraction effect of the electromagnetic force of the coil, two ends of the contact are conducted, the electric energy of the first power supply is transmitted to the charging circuit through the closed contact, and then the charging circuit charges the second power supply, and then realize charging the second power through first power, improve the convenience of charging control, improve the stability of charging. And after the first power supply stops supplying power, the charging circuit can be disconnected from the second control circuit rapidly, the electric quantity loss of the second power supply is reduced, the electric energy storage reliability of the second power supply is improved, the leakage current is reduced, the electric energy waste is reduced, and the use reliability of the second power supply is improved.

As shown in fig. 5, the charging circuit in the power switching circuit provided in the present embodiment includes a charging detection circuit and a charging control circuit. The charging detection circuit is connected with the second power supply and is used for acquiring the charging state of the second power supply; the charging control circuit is connected with the charging detection circuit and the second power supply and is used for controlling the charging state of the second power supply.

In this embodiment, the charging circuit specifically includes a charging detection circuit, the charging detection circuit can be connected to the second power supply, and a specific charging state of the second power supply in the charging process can be obtained through the charging detection circuit; the charging circuit further comprises a charging control circuit, the charging control circuit can be connected with the charging detection circuit and the second power supply, and the charging control circuit can adjust and control the current charging state of the second power supply according to the charging state of the second power supply acquired by the charging detection circuit. The charging detection circuit is arranged in the charging circuit, so that the charging circuit can acquire the specific charging state of the second power supply in the charging process, the charging control circuit can control and adjust according to the acquired charging state, the charging stability of the second power supply is improved, the charging efficiency is improved, and the charging time is shortened.

As shown in fig. 4, the charging detection circuit in the power supply switching circuit provided in this embodiment includes: a current detection resistor R5 and a voltage dividing resistor R6. The current detection resistor R5 is connected to a second power supply, and is configured to obtain a charging current; one end of the voltage-dividing resistor R6 is connected to the second power supply, the other end of the voltage-dividing resistor R6 is grounded through a fifth resistor R7, and the voltage-dividing resistor R6 is used for obtaining a charging voltage.

In this embodiment, the charge detection circuit specifically includes a current detection resistor R5 and a voltage dividing resistor R6; one end of the current detection resistor R5 is connected to a second power supply, and by connecting the second power supply, the charging current of the second power supply in the charging process of the charging circuit can be obtained, and the current charging state of the second power supply can be obtained through the charging current; one end of the voltage dividing resistor R6 is connected to the second power supply, the other end of the voltage dividing resistor R6 is grounded through a fifth resistor R7, the voltage dividing resistor R6 is connected to the second power supply, so that the voltage dividing resistor R6 can be connected in series with the second power supply for voltage division, the voltage of the second power supply is obtained in an equal proportion in a series voltage division manner, and thus, the equal proportion second power supply voltage with lower voltage is obtained, and the current charging state of the second power supply can be obtained through the obtained charging voltage. Constitute the detection circuitry that charges through using current detection resistance R5 and divider resistance R6, the structure of the detection circuitry that charges has been simplified, the circuit complexity of the detection circuitry that charges has been reduced, the circuit fault rate has been reduced, detection efficiency has been improved, and, through set up fifth resistance R7 between divider resistance R6 and ground connection, reduce the second power and pass through the leakage current of divider resistance R6 earthing terminal, reduce the electric quantity of second power and run off, improve the electric energy storage reliability of second power, reduce the leakage current, reduce the electric energy waste, improve the use reliability of second power.

As shown in fig. 4, the charging control circuit in the power switching circuit provided in this embodiment includes; a transistor Q3 and a charge controller U1. The drain of the transistor Q3 is connected to a second power supply, and the source of the transistor Q3 is grounded; the first pin and the third pin of the charging controller U1 are respectively connected with two ends of a current detection resistor R5, the second pin of the charging controller U1 is connected with a voltage dividing resistor R6, the fifth pin of the charging controller U1 is connected with the gate of a transistor Q3, the sixth pin of the charging controller U1 is grounded, and the charging controller U1 is used for controlling the charging state of the second power supply according to the charging current and the charging voltage.

In this embodiment, the charging control circuit is provided with a transistor Q3 and a charging controller U1, and by providing the charging controller U1, and connecting the charging controller U1 with a current detection resistor R5 and a voltage dividing resistor R6 of the charging detection circuit, the charging controller U1 can control the transistor Q3 according to the obtained charging current and the obtained charging voltage, and the current charging state of the second power supply can be controlled by controlling the transistor Q3, so that the charging control circuit is simplified, the complexity of the charging control circuit is reduced, the circuit failure rate is reduced, and the charging efficiency is improved.

Further, the charging controller U1 is CN3300 boost type battery charging controller U1, and by using this model charging controller U1 and cooperating with other components of the charging circuit, the voltage drop of the charging circuit can be reduced, the charging voltage of the charging circuit can be increased, the charging voltage of the second power supply can be increased, and further the charging capacity of the second power supply can be increased, the capacity utilization rate of the second power supply can be increased, and the electric energy storage can be increased.

As shown in fig. 4, the charging circuit in the power switching circuit provided in this embodiment further includes: an inductor L1 and a first voltage regulator tube D4, wherein the inductor L1 is connected with a current detection resistor R5 and a second power supply and is used for providing an inductor L1 current; the negative electrode of the first voltage-regulator tube D4 is connected with an inductor L1, and the positive electrode of the first voltage-regulator tube D4 is connected with a second power supply.

In this embodiment, an inductor L1 is disposed in the charging circuit, and one end of the inductor L1 is connected to the current detection resistor R5, and the other end is connected to the second power supply and to the drain of the transistor Q3, so as to pass the inductor L1 current required for charging. When the charging circuit is connected with the first power supply, the charging controller U1 controls the transistor Q3 to be switched on, the current of the inductor L1 rises, the current of the inductor L1 starts to accumulate the current of the inductor L1, when the current of the inductor L1 rises to the upper limit set by the current detection resistor R5, the charging controller U1 controls the transistor Q3 to be switched off, at this time, the current of the inductor L1 falls, the energy in the inductor L1 is transferred to the second power supply, when the current of the inductor L1 falls to the lower limit set by the current detection resistor R5, the charging controller U1 controls the transistor Q3 to be switched on again, the cycle is repeated until the voltage of the voltage division resistor R6 obtained by the charging controller U1 reaches the upper limit of the preset voltage, the charging process is finished, the charging controller U1 controls the transistor Q3 to be kept in the off state, the charging circuit finishes charging the second power supply, and when the voltage of the voltage division resistor R6 falls to the upper limit of the preset voltage, the charging circuit enters the charging state again, and repeatedly executing the charging step to charge the second power supply again.

The second power supply is charged by using the transistor Q3 to control the current of the inductor L1, so that the charging voltage can be increased, the voltage drop of the charging circuit is reduced, the charging voltage of the second power supply is increased, the charging capacity of the second power supply is improved, the capacity utilization rate of the second power supply is increased, the electric energy reserve is increased, and the charging efficiency is improved.

As shown in fig. 4, the charging circuit in the power switching circuit provided in this embodiment further includes: a first capacitor C1, a second capacitor C2 and a third capacitor C3, wherein one end of the first capacitor C1 is connected with the current detection resistor R5, and the other end is grounded; a second capacitor C2, wherein one end of the second capacitor C2 is connected to the fourth pin of the charge controller U1, and the other end is grounded; and a third capacitor C3, wherein one end of the third capacitor C3 is connected to the second power supply, and the other end is grounded.

In this embodiment, the charging circuit is further provided with a first capacitor C1, one end of the first capacitor C1 is connected with the current detection resistor R5, and the other end of the first capacitor C1 is grounded, and by providing the first capacitor C1 at the current detection resistor R5, the influence of the fluctuation of the first power supply voltage on the detection accuracy of the current detection resistor R5 can be reduced, the circuit noise interference can be reduced, the detection accuracy of the current detection resistor R5 can be improved, and the charging efficiency of the charging circuit can be improved.

The charging circuit is further provided with a second capacitor C2, one end of the second capacitor C2 can be connected with a fourth pin arranged on the charging controller U1, the other end of the second capacitor C2 is grounded, the fourth pin arranged on the charging controller U1 is provided with a second capacitor C2, the fourth pin arranged on the charging controller U1 can be emptied, the influence of a 5V (volt) power supply on the charging circuit at the fourth pin is reduced, the circuit noise interference is reduced, the control accuracy of the charging controller U1 is improved, and the charging efficiency of the charging circuit is improved.

The charging circuit is further provided with a third capacitor C3, one end of the third capacitor C3 is connected with the second power supply, the other end of the third capacitor C3 is grounded, and the third capacitor C3 is arranged at the second power supply, so that the influence of voltage fluctuation of the second power supply on the charging process of the charging circuit can be reduced, noise interference of the charging circuit is reduced, and the charging efficiency of the charging circuit is improved.

As shown in fig. 6 and 7, the power switching circuit in the power switching circuit provided in the present embodiment further includes: the detection circuit is connected with the mains supply and the first control circuit and comprises a rectification circuit and a signal processing circuit; the rectification circuit comprises a rectification bridge U2; the rectification circuit is connected with a mains supply through an eighth resistor R10 and is used for rectifying the current output by the mains supply; the signal processing circuit is connected with the rectifying circuit, and the signal processing circuit can determine that the first power supply is in a power supply state or a power failure state according to the current processed by the rectifying circuit.

In this embodiment, the power switching circuit further includes a detection circuit, which is connected to the mains power supply and the first control circuit, and specifically, the detection circuit includes a rectification circuit and a signal processing circuit. The rectifying circuit is connected with a mains supply, and can rectify the obtained mains supply current to convert the alternating current of the mains supply into a direct current power supply and supply the direct current power supply to the signal processing circuit, so that the current processing of the signal processing circuit is facilitated. The signal processing circuit can be connected with the rectifying circuit, and whether the first power supply is in a power supply state or a power failure state can be determined through current output by the rectifying circuit.

By arranging the detection circuit, the power supply state of the first power supply can be identified, whether the first power supply supplies power normally or not is determined, the controller can control the circuit according to the power supply state of the first power supply, the identification accuracy of the power supply state of the first power supply is improved, the complexity of the power supply state identification circuit is reduced, the identification efficiency is improved, and the current is used as the basis for checking the power supply state, so that the influence of voltage fluctuation on the detection precision can be reduced, the misjudgment of a detection result is avoided, and the detection precision is improved.

As shown in fig. 7, the signal processing circuit in the power switching circuit provided in the present embodiment includes: the power supply comprises a second voltage-stabilizing tube D5, a fourth capacitor C4 and a third power supply, wherein the anode of the second voltage-stabilizing tube D5 is connected with the anode of the rectifying circuit, and the cathode of the second voltage-stabilizing tube D5 is connected with the cathode of the rectifying circuit; the fourth capacitor C4 is connected in parallel with the second voltage regulator D5; the third power supply is connected to the positive electrode of the second regulator tube D5.

In this embodiment, the signal processing circuit specifically includes a second voltage regulator D5, the positive electrode of the second voltage regulator D5 is connected with the positive electrode of the rectifying circuit, and the negative electrode is connected with the negative electrode of the rectifying circuit, and the voltage regulator is arranged between the positive electrode and the negative electrode of the rectifying circuit, so that the voltage regulator can regulate the current output by the rectifying circuit, reduce the influence of the output voltage on the detection precision, and improve the detection accuracy; one end of the fourth capacitor C4 is connected in parallel with the second voltage regulator tube D5, and the capacitor is arranged in the signal processing circuit, so that the noise interference of the output current of the rectifying circuit can be reduced, the influence of the noise interference on the detection precision is reduced, and the detection accuracy is improved.

As shown in fig. 7, the signal processing circuit in the power switching circuit provided in this embodiment further includes: the photoelectric switch U3 is connected with the rectifying circuit through a sixth resistor R8; the negative electrode of the light receiving end of the photoelectric switch U3 is grounded, and the positive electrode of the light receiving end of the photoelectric switch U3 is connected with the detection power supply through a seventh resistor R9.

In this embodiment, the signal processing circuit further includes a photo switch U3, when the rectifying circuit outputs current, the current flows in from the positive electrode of the photo switch U3 connected to the rectifying circuit, and flows out from the negative electrode, in this process, the light emitting diode inside the photo switch U3 is lit, when the light emitting diode is lit, the light receiving end is turned on, the current of the detection power supply flows in through the positive electrode of the light receiving end, and flows out from the negative electrode, so as to generate a detection current, and by controlling the on state of the light receiving end, the flowing state of the detection power supply current can be controlled, so as to determine whether the first power supply is in the power supply state. The structure complexity of the signal processing circuit is reduced, the circuit fault rate is reduced, the detection reliability is improved, the influence of voltage fluctuation on the detection precision can be reduced by detecting through the current, the misjudgment of the detection result is avoided, and the detection precision is improved.

The embodiment also provides a circuit board comprising the power switching circuit as in any one of the above embodiments.

In this embodiment, a circuit board is provided, which includes the power switching circuit as described in any one of the above embodiments, and therefore, all the advantages of the power switching circuit are achieved, and are not described herein again.

Particularly, the power supply switching circuit controls the switching of the power supply, can maintain the normal operation of the circuit through the second power supply when the first power supply is abnormally powered down, improves the stability of the circuit in operation, improves the operation reliability, and because the first control circuit accesses the second power supply into the power supply switching circuit through the first switch circuit when the first power supply is powered down abnormally, the second power supply can immediately supply power to the first control circuit without any additional control and contact action when the first power supply is abnormally powered down, maintains the normal operation of the first control circuit, ensures that the process of switching the power supply switching circuit from the power supply of the first power supply to the power supply of the second power supply is more stable, improves the smoothness of the power supply switching process, reduces the voltage jitter condition in the power supply switching process, and improves the operation stability after the power supply switching, and contactless action is carried out in the switching process, the influence of contact voltage drop on the stability of power supply switching is avoided, and the operation reliability and stability of the circuit are improved.

And the second control circuit is used for controlling the second switch circuit, and the on-off state of the first power supply and the charging circuit is controlled through the on-off state of the second switch circuit, so that when the working state of the first power supply is in a power supply state, the second control circuit can control the charging circuit to charge the second power supply through the first power supply, the electric quantity of the second power supply is maintained to be sufficient, the second power supply can have sufficient backup electric quantity to maintain the operation of the circuit when the first power supply is powered off, the power supply stability and reliability of the second power supply are improved, and the stability and reliability of the circuit during operation are improved. And after the first power supply stops supplying power, the second switch circuit can disconnect the connection between the charging circuit and the second control circuit, so that the phenomenon that after the charging is stopped, the second power supply leaks current to the second control circuit through the second switch circuit to cause the electric quantity of the second power supply to be lost and influence the electric energy storage of the second power supply is avoided, and by disconnecting the second switch circuit, the electric energy storage reliability of the second power supply is improved, the leakage current is reduced, the electric energy waste is reduced, and the use reliability of the second power supply is improved.

In addition, by arranging the detection circuit, the power supply state of the first power supply can be identified, whether the first power supply supplies power normally or not is determined, the controller can control the circuit according to the power supply state of the first power supply, the identification accuracy of the power supply state of the first power supply is improved, the complexity of the power supply state identification circuit is reduced, the detection accuracy is improved through the identification efficiency, and in addition, the influence of voltage fluctuation on the detection accuracy can be reduced by using the current as the basis for checking the power supply state, the misjudgment of the detection result is avoided, and the detection accuracy is improved.

The embodiment also provides an unmanned vending machine which comprises the circuit board in the embodiment.

In this embodiment, there is provided an unmanned vending machine including the circuit board as in the above embodiments, thereby having all the advantages of the circuit board, which will not be described herein again.

In the description of the present invention, the term "plurality" means two or more, and unless otherwise specifically limited, the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present embodiment and for simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention; the terms "connected," "mounted," "secured," and the like are to be construed broadly and include, for example, fixed connections, removable connections, or integral connections; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the description of the present invention, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In the present invention, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A power switching circuit, wherein the power switching circuit is connected to a first power source and a second power source, respectively, the power switching circuit comprising:

a first control circuit connected to the first power supply;

a first switching circuit connected between the first control circuit and the second power supply;

when the first power supply is in a power supply state, the first control circuit controls the first switch circuit to be in a closed state so that the second power supply is connected to the power supply switching circuit, and the first power supply supplies power to the first control circuit; and under the condition that the first power supply is in a power-down state, the second power supply supplies power to the first control circuit.

2. The power switching circuit of claim 1, wherein the first switching circuit comprises:

a first control end and a first switching end of the first relay are connected with the first power supply, and a second control end of the first relay is connected with the first control circuit;

the input end of the Schottky diode is connected with the second power supply, and the output end of the Schottky diode is connected with the second switching end of the first relay;

under the condition that the first power supply is in a power supply state, the first control circuit controls the first switching end and the second switching end of the first relay to be conducted so as to enable the second power supply to be connected to the power supply switching circuit, and when the voltage of the first power supply is larger than that of the second power supply, the first power supply supplies power to the first control circuit.

3. The power switching circuit of claim 2, wherein the first switching circuit further comprises:

and the input end of the first diode is connected with the first control circuit, and the output end of the first diode is connected with the first power supply.

4. The power switching circuit of claim 1, wherein the first control circuit comprises:

a single chip microcomputer;

the base electrode of the first triode is connected with the singlechip through a first resistor, the emitting electrode of the first triode is grounded, and the collecting electrode of the first triode is connected with the first switching circuit;

and the second resistor is connected with the first resistor and the emitting electrode of the first triode.

5. The power switching circuit of claim 4, further comprising:

the second control circuit is connected with the first power supply;

a second switching circuit connected between the second control circuit and the second power supply;

a charging circuit connected to the second switching circuit and the second power supply;

wherein, under the condition that the first power supply is in a power supply state, the second control circuit controls the second switch circuit to be in a closed state, so that the charging circuit charges the second power supply; the second control circuit controls the second switching circuit to be in an off state when the first power supply is in a power-off state.

6. The power switching circuit of claim 5, wherein the second control circuit comprises:

the base electrode of the second triode is connected with the singlechip through a third resistor, and the emitting electrode of the second triode is grounded;

and the fourth resistor is connected with the third resistor and the emitting electrode of the second triode.

7. The power switching circuit of claim 5, wherein the second switching circuit comprises:

a first control end and a first switching end of the second relay are connected with the first power supply, a second control end of the second relay is connected with the second control circuit, and a second switching end of the second relay is connected with the charging circuit;

and the input end of the second diode is connected with the second control circuit, and the output end of the second diode is connected with the first power supply.

8. The power switching circuit of claim 5, wherein the charging circuit comprises:

the charging detection circuit is connected with the second power supply and used for acquiring the charging state of the second power supply;

and the charging control circuit is connected with the charging detection circuit and the second power supply and is used for controlling the charging state of the second power supply.

9. The power supply switching circuit according to claim 8, wherein the charge detection circuit comprises:

the current detection resistor is connected with the second power supply and used for acquiring charging current;

and one end of the divider resistor is connected with the second power supply, the other end of the divider resistor is grounded through a fifth resistor, and the divider resistor is used for acquiring charging voltage.

10. The power switching circuit according to claim 9, wherein the charge control circuit comprises;

a transistor, a drain of which is connected to the second power supply and a source of which is grounded;

the charging controller, charging controller's first pin and third pin respectively with the both ends of current detection resistance are connected, charging controller's second pin with divider resistance is connected, charging controller's fifth pin with the grid of transistor is connected, charging controller's sixth pin ground connection, charging controller is used for according to charging current with charging voltage is right the charged state of second power is controlled.

11. The power switching circuit of claim 10, wherein the charging circuit further comprises:

the inductor is connected with the current detection resistor and the second power supply and used for providing inductor current;

and the negative electrode of the first voltage-stabilizing tube is connected with the inductor, and the positive electrode of the first voltage-stabilizing tube is connected with the second power supply.

12. The power switching circuit of claim 10, wherein the charging circuit further comprises:

one end of the first capacitor is connected with the current detection resistor, and the other end of the first capacitor is grounded;

one end of the second capacitor is connected with a fourth pin of the charge controller, and the other end of the second capacitor is grounded;

and one end of the third capacitor is connected with the second power supply, and the other end of the third capacitor is grounded.

13. The power supply switching circuit according to any one of claims 1 to 12, further comprising:

the detection circuit is connected with the mains supply and the first control circuit and comprises a rectification circuit and a signal processing circuit;

the rectification circuit is connected with the mains supply and is used for rectifying the current output by the mains supply;

the signal processing circuit is connected with the rectifying circuit, and the signal processing circuit can determine that the first power supply is in the power supply state or the power failure state according to the current processed by the rectifying circuit.

14. The power switching circuit of claim 13, wherein the signal processing circuit comprises:

the anode of the second voltage-stabilizing tube is connected with the anode of the rectifying circuit, and the cathode of the second voltage-stabilizing tube is connected with the cathode of the rectifying circuit;

the fourth capacitor is connected in parallel with the second voltage-regulator tube;

and the third power supply is connected with the anode of the second voltage-regulator tube.

15. The power switching circuit of claim 13, wherein the signal processing circuit further comprises:

the photoelectric switch is connected with the rectifying circuit through a sixth resistor;

the negative electrode of the light receiving end of the photoelectric switch is grounded, and the positive electrode of the light receiving end of the photoelectric switch is connected with the detection power supply through a seventh resistor.

16. A circuit board, comprising:

the power switching circuit of any one of claims 1 to 15.

17. An unmanned vending machine, comprising:

the circuit board of claim 16.