Power supply switching circuit

Abstract

The utility model discloses a power supply switching circuit which comprises a plurality of battery pack access interfaces which are sequentially connected in series and a plurality of switching circuits, each battery pack access interface comprises a battery pack anode connecting end and a battery pack cathode connecting end, and the battery pack anode connecting end of the first battery pack access interface is connected with a power supply anode end. The battery pack negative electrode connecting end of the battery pack access interface at the last position is grounded; the switching circuits and the battery pack access interfaces are in one-to-one correspondence and are mutually connected in parallel, and the second end of the switching circuit corresponding to the battery pack access interface is connected with the first end of the switching circuit corresponding to the next battery pack access interface and the battery pack anode connecting end of the next battery pack access interface. The first end of the switching circuit corresponding to the first battery pack access interface is connected with the power supply positive electrode end, and the second end of the switching circuit corresponding to the last battery pack access interface is grounded.

Description

Technical Field

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

[0002] Most existing electronic products require two or more batteries connected in series to work properly. When the number of connected batteries is reduced, this type of product will directly lead to a failure to power any module of the product, and the product as a whole will not work. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a power supply switching circuit, so that when there is a connected battery, power can be supplied to the inside of the product, without waiting for all batteries to be connected before powering the inside of the product.

[0004] In order to solve the above technical problems, the purpose of the utility model is achieved through the following technical solutions: providing a power supply switching circuit, including a plurality of battery pack access interfaces and a plurality of switch circuits connected in series in sequence, each of the battery pack access interfaces including a battery pack positive connection terminal and a battery pack negative connection terminal, the battery pack negative connection terminal of the battery pack access interface is connected to the battery pack positive connection terminal of the next battery pack access interface, the battery pack positive connection terminal of the first battery pack access interface is connected to the positive power supply terminal, and the battery pack negative connection terminal of the last battery pack access interface is grounded; the switch circuit is connected to the battery pack access interface one by one Correspondingly, the first end of the switch circuit is connected to the battery pack positive connection end of the battery pack access interface, and the second end of the switch circuit is connected to the battery pack negative connection end of the battery pack access interface, so that the switch circuit is connected in parallel with the corresponding battery pack, and the second end of the switch circuit corresponding to the battery pack access interface is connected to the first end of the switch circuit corresponding to the next battery pack access interface and the battery pack positive connection end of the next battery pack access interface, the first end of the switch circuit corresponding to the first battery pack access interface is connected to the positive power supply end, and the second end of the switch circuit corresponding to the last battery pack access interface is grounded.

[0005] The beneficial technical effect of the present invention is that the power supply switching circuit of the present invention is provided with a plurality of battery pack access interfaces connected in series in sequence and switch circuits corresponding to and connected in parallel with the battery pack access interfaces one by one, so that when the battery pack access interface is not connected to the battery pack, the corresponding parallel switch circuit is turned on, and when the battery pack access interface is connected to the battery pack, the corresponding parallel switch circuit is turned off, so that a path is formed between the positive power supply terminal, the switch circuit corresponding to the battery pack access interface not connected to the battery pack, the battery pack access interface connected to the battery pack, and the ground, so that the positive power supply terminal can be powered as long as there is at least one battery pack access interface connected to the battery pack. When the number of connected battery packs is reduced, some battery packs are replaced, some battery packs are missing, or additional battery packs are added, the positive power supply terminal can still be powered to power the application circuit inside the product connected to the positive power supply terminal. There is no need to wait until all batteries are connected before powering the inside of the product. This can meet the requirement that the MCU of the product that is not fully connected to the battery pack can work, and the utility model is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0007] Figure 1 A circuit schematic diagram of a power supply switching circuit provided in an embodiment of the utility model when connected to an application circuit. DETAILED DESCRIPTION

[0008] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0009] See also Figure 1 As shown, Figure 1A circuit schematic diagram of a power supply switching circuit provided in an embodiment of the utility model when connected to an application circuit, wherein the power supply switching circuit includes a plurality of battery pack access interfaces and a plurality of switch circuits connected in series in sequence, wherein each of the battery pack access interfaces includes a battery pack positive connection terminal and a battery pack negative connection terminal, the battery pack negative connection terminal of the battery pack access interface is connected to the battery pack positive connection terminal of the next battery pack access interface, the battery pack positive connection terminal of the first battery pack access interface is connected to the positive power supply terminal V+, and the battery pack negative connection terminal of the last battery pack access interface is grounded; the switch circuit is connected one by one to the battery pack access interface The first end of the switch circuit is connected to the battery pack positive connection end of the battery pack access interface, and the second end of the switch circuit is connected to the battery pack negative connection end of the battery pack access interface, so that the switch circuit is connected in parallel with the corresponding battery pack, and the second end of the switch circuit corresponding to the battery pack access interface is connected to the first end of the switch circuit corresponding to the next battery pack access interface and the battery pack positive connection end of the next battery pack access interface, the first end of the switch circuit corresponding to the first battery pack access interface is connected to the positive power supply terminal V+, and the second end of the switch circuit corresponding to the last battery pack access interface is grounded.

[0010] The positive power supply terminal V+ is used to output the electrical signal of the battery pack connected to the battery pack access interface, and can be connected to the input terminal of the application circuit 20 inside the product to power the application circuit 20. The output terminal of the application circuit 20 is grounded. The power supply switching circuit is configured by setting a plurality of battery pack access interfaces connected in series in sequence and switch circuits corresponding to and connected in parallel with the battery pack access interfaces one by one, so that when the battery pack access interface is not connected to the battery pack, the corresponding parallel switch circuit is turned on, and when the battery pack access interface is connected to the battery pack, the corresponding parallel switch circuit is turned off, so that the positive power supply terminal V+, which is not connected to the battery pack, is connected to the battery pack. A path is formed between the switch circuit corresponding to the battery pack access interface, the battery pack access interface connected to the battery pack, and the ground, so that as long as there is at least one battery pack access interface connected to the battery pack, the positive power supply terminal V+ can be powered. When the number of connected battery packs is reduced, some battery packs are replaced, some battery packs are missing, or additional battery packs are added, the positive power supply terminal V+ can still be powered to power the application circuit 20 inside the product connected to the positive power supply terminal V+. There is no need to wait until all batteries are connected before powering the inside of the product, which can meet the need for the MCU of the product that is not fully connected to work, and is highly practical.

[0011] Specifically, in this embodiment, the switch circuit includes a diode, a first resistor, a first switch tube, a second switch tube, and a second resistor, the cathode of the diode serves as the first end of the switch circuit, the anode of the diode is connected to one end of the first resistor and the output end of the first switch tube, the control end of the first switch tube is connected to the other end of the first resistor and the output end of the second switch tube, the input end of the first switch tube is connected to the control end of the second switch tube and one end of the second resistor, the other end of the second resistor is connected to the input end of the second switch tube, and the input end of the second switch tube serves as the second end of the switch circuit. When the battery pack access interface is connected to the battery pack, the diode does not have a unidirectional conduction condition, and the diode is cut off. At this time, the first switch tube and the second switch tube also do not have a conduction condition, and the switch circuit is turned off. When the battery pack access interface is not connected to a battery pack, the switching circuit corresponding to the battery pack access interface and the battery pack access status of the battery pack access interfaces before and after the battery pack access interface can be turned on to form a path between the positive power supply terminal V+, the switching circuit corresponding to the battery pack access interface not connected to the battery pack, the battery pack access interface connected to the battery pack, and the ground.

[0012] Specifically, in this embodiment, both the first switch tube and the second switch tube are NPN transistors, the anode of the diode is connected to one end of the first resistor and the emitter of the first switch tube, the base of the first switch tube is connected to the other end of the first resistor and the emitter of the second switch tube, the collector of the first switch tube is connected to the base of the second switch tube and one end of the second resistor, the other end of the second resistor is connected to the collector of the second switch tube, and the collector of the second switch tube serves as the second end of the switch circuit. Wherein, both the first switch tube and the second switch tube are NPN transistors, when a battery pack access interface is not connected to a battery pack but there is a battery pack access interface connected to a battery pack in the power supply switching circuit and the current flowing through the first resistor of the switch circuit corresponding to the battery pack access interface not connected to the battery pack is too small and the voltage drop on the first resistor is less than 0.7V, the voltage difference between the base and the emitter of the first switch tube is less than 0.7V, and the first switch tube is turned off; when the current flowing through the first resistor of the switch circuit corresponding to the battery pack access interface not connected to the battery pack reaches When the voltage drop on the first resistor is greater than 0.7V and the voltage difference between the base and the emitter of the first switch tube is greater than 0.7V, the first switch tube is turned on, and the voltage difference between the base and the emitter of the second switch tube is pulled down to a low level, so that the second switch tube is turned off, and the second switch tube is turned off so that the current on the first resistor instantly becomes 0A, and the voltage difference between the base and the emitter of the first switch tube also becomes 0V. The first switch tube is turned off, so that the voltage difference between the base and the emitter of the second switch tube becomes a high level, so that the second switch tube is turned on. The entire transition time is short, and the capacitor in the subsequent circuit can provide voltage during this transition time, so that continuous power supply can be achieved. A current limiting circuit is formed between the first switch tube and the second switch tube, so that the current in the loop formed between the first switch tube and the second switch tube is limited to the current value obtained by dividing the voltage when the first switch tube is turned on by the first resistor. The collector voltage of the second switch tube is equal to the base voltage and both are greater than the emitter voltage, and the voltage difference between the base and the emitter of the second switch tube is greater than 0.7V, and the second switch tube is turned on. Combined with the working states of the first switch tube and the second switch tube, when the battery pack access interface is not connected to a battery pack, the switch circuit corresponding to the battery pack access interface is turned on and has a current limiting function, so that the electrical signals of the battery packs connected to other battery pack access interfaces can be circulated to the positive power supply terminal V+, so as to power the application circuit 20 connected to the positive power supply terminal V+, so that the application circuit 20 can continue to work.

[0013] Specifically, in this embodiment, the number of the battery pack access interfaces is two, namely, a first battery pack access interface and a second battery pack access interface. The battery pack connected to the first battery pack access interface is denoted as a first battery pack B1, and the battery pack connected to the second battery pack access interface is denoted as a second battery pack B2. The number of the switch circuits is two, namely, a first switch circuit 11A and a second switch circuit 11B. The first switch circuit 11A corresponds to and is connected in parallel with the first battery pack access interface, and the second switch circuit 11B corresponds to and is connected in parallel with the second battery pack access interface. The battery pack positive connection terminal of the first battery pack access interface is connected to the positive power supply terminal V+ and the first end of the first switch circuit 11A, the battery pack negative connection terminal of the first battery pack access interface is connected to the second end of the first switch circuit 11A and the battery pack positive connection terminal of the second battery pack access interface, the battery pack positive connection terminal of the second battery pack access interface is connected to the second end of the first switch circuit 11A and the first end of the second switch circuit 11B, the battery pack negative terminal of the second battery pack access interface is connected to the second end of the second switch circuit 11B and ground, and the second end of the second switch circuit 11B is grounded.

[0014] Specifically, the battery pack positive electrode connection terminal and the battery pack negative electrode connection terminal of the battery pack access interface are connected to the positive electrode and negative electrode of the battery pack respectively, and the battery includes a battery module, and the battery module includes at least one battery. The battery pack positive electrode connection terminal of the first battery pack access interface is connected to the positive electrode of the first battery pack B1, the battery pack negative electrode connection terminal of the first battery pack access interface is connected to the negative electrode of the first battery pack B1, the battery pack positive electrode connection terminal of the second battery pack access interface is connected to the positive electrode of the second battery pack B2, and the battery pack negative electrode connection terminal of the second battery pack access interface is connected to the negative electrode of the second battery pack B2.

[0015] Correspondingly, the diode, the first resistor, the first switch tube, the second switch tube and the second resistor of the first switch circuit 11A are respectively recorded as D1, R1, Q1, Q2 and R2, and the diode, the first resistor, the first switch tube, the second switch tube and the second resistor of the second switch circuit 11B are respectively recorded as D2, R3, Q3, Q4 and R4. The cathode of the diode D1 of the first switch circuit 11A serves as the first end of the first switch circuit 11A, and the cathode of the diode D1 of the first switch circuit 11A is connected to the positive power supply terminal V+ and the positive battery connection terminal of the first battery pack access interface so as to be connected to the positive electrode of the first battery pack B1 connected to the first battery pack access interface, the anode of the diode D1 of the first switch circuit 11A is connected to one end of the first resistor R1 of the first switch circuit 11A and the emitter of the first switch tube Q1 of the first switch circuit 11A, and the base of the first switch tube Q1 of the first switch circuit 11A is connected to the positive power supply terminal V+ and the positive battery connection terminal of the first battery pack access interface. The other end of the first resistor R1 of the first switching circuit 11A is connected to the emitter of the second switching tube Q2 of the first switching circuit 11A, the collector of the first switching tube Q1 of the first switching circuit 11A is connected to the base of the second switching tube Q2 of the first switching circuit 11A and one end of the second resistor R2 of the first switching circuit 11A, the other end of the second resistor R2 of the first switching circuit 11A is connected to the collector of the second switching tube Q2 of the first switching circuit 11A, and the collector of the second switching tube Q2 of the first switching circuit 11A serves as the second end of the first switching circuit 11A. The cathode of the diode D2 of the second switch circuit 11B serves as the first end of the second switch circuit 11B, the cathode of the diode D1 of the second switch circuit 11B is connected to the negative electrode connection end of the battery pack of the first battery pack access interface, the positive electrode connection end of the battery pack of the second battery pack access interface, and the collector of the second switch tube Q2 of the first switch circuit 11A, then the first end of the second switch circuit 11B is connected to the positive electrode of the second battery pack B2 connected to the second battery pack access interface, the anode of the diode D2 of the second switch circuit 11B is connected to one end of the first resistor R3 of the second switch circuit 11B and the emitter of the first switch tube Q3 of the second switch circuit 11B The base of the first switch tube Q3 of the second switch circuit 11B is connected to the other end of the first resistor R3 of the second switch circuit 11B and the emitter of the second switch tube Q4 of the second switch circuit 11B, the collector of the first switch tube Q3 of the second switch circuit 11B is connected to the base of the second switch tube Q4 of the second switch circuit 11B and one end of the second resistor R4 of the second switch circuit 11B, the other end of the second resistor R4 of the second switch circuit 11B is connected to the collector of the second switch tube Q4 of the second switch circuit 11B, and the collector of the second switch tube Q4 of the second switch circuit 11B serves as the second end of the second switch circuit 11B.

[0016] Specifically, in the present embodiment, the number of batteries in the battery module is two, and the two batteries are connected in series. Of course, in some embodiments, the number of batteries in the battery module is one, the positive electrode of the battery is connected to the positive electrode connection terminal of the battery pack access interface, and the negative electrode of the battery is connected to the negative electrode connection terminal of the battery pack access interface. In addition, in other embodiments, the number of batteries in the battery module may be three or more, and the batteries in the battery module are connected in series in sequence, the positive electrode of the first battery in the battery module is connected to the positive electrode connection terminal of the battery pack access interface, and the negative electrode of the last battery in the battery module is connected to the negative electrode connection terminal of the battery pack access interface.

[0017] To summarize, the power supply switching circuit of the present invention sets a number of battery pack access interfaces connected in series in sequence and switch circuits corresponding to the battery pack access interfaces and connected in parallel one by one, so that when the battery pack access interface is not connected to the battery pack, the corresponding parallel switch circuit is turned on, and when the battery pack access interface is connected to the battery pack, the corresponding parallel switch circuit is turned off, so that a path is formed between the positive power supply terminal, the switch circuit corresponding to the battery pack access interface not connected to the battery pack, the battery pack access interface connected to the battery pack, and the ground, so that the positive power supply terminal can be powered as long as there is at least one battery pack access interface connected to the battery pack. When the number of connected battery packs is reduced, some battery packs are replaced, some battery packs are missing, or additional battery packs are added, the positive power supply terminal can still be powered to power the application circuit inside the product connected to the positive power supply terminal. There is no need to wait until all batteries are connected before powering the inside of the product. This can meet the need for the MCU of a product that is not fully connected to a battery pack to work, and is highly practical.

[0018] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the utility model, and these modifications or replacements should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A power supply switching circuit, characterized in that: include: A plurality of battery pack access interfaces connected in series in sequence, each of the battery pack access interfaces comprising a battery pack positive electrode connection terminal and a battery pack negative electrode connection terminal, the battery pack negative electrode connection terminal of the battery pack access interface being connected to the battery pack positive electrode connection terminal of the next battery pack access interface, the battery pack positive electrode connection terminal of the first battery pack access interface being connected to the positive power supply terminal, and the battery pack negative electrode connection terminal of the last battery pack access interface being grounded; A plurality of switch circuits, wherein the switch circuits correspond one-to-one to the battery pack access interfaces, the first end of the switch circuit is connected to the battery pack positive connection end of the battery pack access interface, and the second end of the switch circuit is connected to the battery pack negative connection end of the battery pack access interface, so that the switch circuit is connected in parallel with the corresponding battery pack, the second end of the switch circuit corresponding to the battery pack access interface is connected to the first end of the switch circuit corresponding to the next battery pack access interface and the battery pack positive connection end of the next battery pack access interface, the first end of the switch circuit corresponding to the first battery pack access interface is connected to the positive power supply end, and the second end of the switch circuit corresponding to the last battery pack access interface is grounded.

2. The power supply switching circuit according to claim 1, characterized in that: The switching circuit includes a diode, a first resistor, a first switching tube, a second switching tube and a second resistor. The cathode of the diode serves as the first end of the switching circuit, the anode of the diode is connected to one end of the first resistor and the output end of the first switching tube, the control end of the first switching tube is connected to the other end of the first resistor and the output end of the second switching tube, the input end of the first switching tube is connected to the control end of the second switching tube and one end of the second resistor, the other end of the second resistor is connected to the input end of the second switching tube, and the input end of the second switching tube serves as the second end of the switching circuit.

3. The power supply switching circuit according to claim 2, characterized in that: The first switch tube and the second switch tube are both NPN transistors, the anode of the diode is connected to one end of the first resistor and the emitter of the first switch tube, the base of the first switch tube is connected to the other end of the first resistor and the emitter of the second switch tube, the collector of the first switch tube is connected to the base of the second switch tube and one end of the second resistor, the other end of the second resistor is connected to the collector of the second switch tube, and the collector of the second switch tube serves as the second end of the switch circuit.

4. The power supply switching circuit according to claim 1, characterized in that: The number of the battery pack access interfaces is two, and the number of the switch circuits is two.

5. The power supply switching circuit according to claim 1, characterized in that: The battery pack positive electrode connection terminal and the battery pack negative electrode connection terminal of the battery pack access interface are respectively connected to the positive electrode and the negative electrode of the battery pack. The battery includes a battery module, and the battery module includes at least one battery.

6. The power supply switching circuit according to claim 5, characterized in that: The battery module includes two batteries, which are connected in series.

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