CN217563343U

CN217563343U - Double-power-supply automatic switching circuit

Info

Publication number: CN217563343U
Application number: CN202123168754.2U
Authority: CN
Inventors: 唐守龙
Original assignee: Nanjing Hongstars Electronic Technolog Co ltd
Current assignee: Nanjing Hongstars Electronic Technolog Co ltd
Priority date: 2021-12-16
Filing date: 2021-12-16
Publication date: 2022-10-11
Anticipated expiration: 2031-12-16

Abstract

The utility model discloses a two power supply automatic switch-over circuits, including external power source and battery positive pole, external power source electric connection has power detection switch-over circuit and lithium battery charging circuit respectively, lithium battery charging circuit passes through lithium cell and power detection switch-over circuit electric connection, power detection switch-over circuit electric connection has the internal work circuit, external power source and battery positive pole are respectively through two input electric connection of A, B and have the AND gate, the anodal electric connection of battery has M1's source electrode in the PMOS pipe, the utility model relates to a power technical field. This two power supply automatic switch-over circuit has solved current electronic equipment when external power supply, and electronic equipment is all through the work of discharging of inside battery limit towards electricity, and this kind of mode not only can harm the battery, still probably damages inside circuit simultaneously, has reduced the problem of battery life-span.

Description

Double-power-supply automatic switching circuit

Technical Field

The utility model relates to a power technical field specifically is a two power supply automatic switch-over circuits.

Background

At present, rechargeable batteries are arranged in a plurality of electronic devices, and the electronic devices can be used by being separated from an external power supply, but the electronic devices also need to work when the external power supply supplies power.

When current electronic equipment is at external power supply, electronic equipment all is through the work of discharging of inside battery limit towards electricity, and this kind of mode not only can harm the battery, still probably damages internal circuit simultaneously, has reduced the battery life-span, therefore this application provides a two power supply automatic switch-over circuits.

Disclosure of Invention

Technical problem to be solved

The utility model provides a not enough to prior art, the utility model provides a two power supply automatic switch-over circuits has solved current electronic equipment when external power supply, and electronic equipment is all through the work of discharging of inside battery limit towards the electricity, and this kind of mode not only can harm the battery, and the while is probably damaged the internal circuit in addition, has reduced the problem of battery life-span.

(II) technical scheme

In order to achieve the above purpose, the utility model discloses a following technical scheme realizes: the utility model provides a two power supply automatic switch-over circuits, includes external power source and battery positive pole, external power source electric connection has power detection switching circuit and lithium battery charging circuit respectively, lithium battery charging circuit passes through lithium cell and power detection switching circuit electric connection, power detection switching circuit electric connection has interior work circuit, external power source and battery positive pole are respectively through two input electric connection of A, B and have the AND gate, battery positive pole electric connection has M1's source electrode in the PMOS pipe.

Preferably, the external power source is electrically connected to the resistor R and the source of the NMOS transistor M2, respectively.

Preferably, one end of the resistor R, which is far away from the external power supply, is grounded, and the drain of the PMOS transistor M1 and the drain of the NMOS transistor M2 are connected together.

Preferably, the and gate can adopt an SN74 series chip.

(III) advantageous effects

The utility model provides a two power supply automatic switch-over circuits. The method has the following beneficial effects:

this two power supply automatic switch-over circuit, power detects switch-over circuit can at first detect whether there is external power supply at present, if not, then directly deliver to interior work circuit lithium battery power supply, if there is external power supply, then automatically, surely deliver to interior work circuit external power supply, cut off lithium battery power supply, lithium battery charging circuit is responsible for charging for the lithium cell, as long as there is external power supply, just charge the lithium cell, can be at the electronic equipment while during operation that charges, can fully protect the lithium cell, reduce the battery loss, and then prolonged lithium cell life.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of the internal structure of the power detection switching circuit of the present invention;

fig. 3 is a schematic diagram of the battery charging circuit of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Referring to fig. 1-3, the present invention provides a technical solution:

the utility model provides a two power supply automatic switch-over circuits, including external power source and battery anodal, external power source electric connection has power detection switch-over circuit and lithium battery charging circuit respectively, lithium battery charging circuit passes through lithium cell and power detection switch-over circuit electric connection, power detection switch-over circuit electric connection has interior work circuit, external power source and battery anodal respectively through A, two input electric connection of B have the AND gate, battery anodal electric connection has M1's in the PMOS pipe source electrode, external power source electric connection has resistance R and NMOS pipe M2's source electrode respectively, resistance R keeps away from external power source's one end ground connection, PMOS pipe M1's drain electrode and NMOS pipe M2's leakage stage are in the same place, the AND gate can adopt SN74 series chip. When the lithium battery works, the battery always stores electric quantity, so that the positive pole of the battery stores voltage, the input end A of the AND gate is at a high level, when no external power supply exists, the input end B of the AND gate is pulled down to the ground through a resistor R and is at a low level, the output of the AND gate is at a low level, the PMOS tube M1 is conducted, the NMOS tube M2 is closed, the positive pole of the battery is connected into an internal working circuit to supply power to the circuit, when the external power supply exists, the input end B of the AND gate is at a high level, the input end A of the AND gate is also at a high level at the moment, the output of the AND gate is at a high level, the PMOS tube M1 is closed, the NMOS tube M2 is conducted, the external power supply is connected into the internal working circuit to supply power to the circuit, the power supply detection switching circuit firstly detects whether the external power supply exists at present, if the power supply does not exist, the lithium battery supply is directly sent to the internal working circuit, if the external power supply exists, the external power supply is automatically switched to the internal working circuit to cut off the lithium battery, the lithium battery is charged as long as the electronic equipment works while being charged, the loss can fully protect the lithium battery, and the service life of the lithium battery is prolonged.

When the power supply is in use, the battery always stores electric quantity to ensure that the anode of the battery stores voltage, the input end A of the AND gate is at high level, when no external power supply exists, the input end B of the AND gate is pulled down to the ground through a resistor R and is at low level, the output of the AND gate is at low level, the PMOS tube M1 is conducted, the NMOS tube M2 is closed, the anode of the battery is connected into an internal working circuit to supply power for the circuit, when the external power supply exists, the input end B of the AND gate is at high level, the input end A of the AND gate is also at high level, the output of the AND gate is at high level, the PMOS tube M1 is closed, the NMOS tube M2 is conducted, external power source inserts interior work circuit, for the circuit power supply, power detects the switching circuit and can at first detect whether there is external power source power supply at present, if not, then directly deliver to interior work circuit lithium battery power supply, if there is external power source, then automatically, surely deliver to interior work circuit with external power source, cut off lithium battery power supply, lithium battery charging circuit is responsible for charging for the lithium cell, as long as there is external power source power supply, just charge the lithium cell, can charge while the during operation in the electronic equipment limit, can fully protect the lithium cell, reduce the battery loss, and then prolonged lithium cell life.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions.

Claims

1. The utility model provides a two power supply automatic switch-over circuits, includes external power source and battery positive pole, its characterized in that: the external power supply is electrically connected with a power supply detection switching circuit and a lithium battery charging circuit respectively, the lithium battery charging circuit is electrically connected with the power supply detection switching circuit through a lithium battery, the power supply detection switching circuit is electrically connected with an internal working circuit, the external power supply and a battery anode are electrically connected with an AND gate through an A input end and a B input end respectively, and the battery anode is electrically connected with a source electrode of M1 in a PMOS (P-channel metal oxide semiconductor) tube.

2. The dual power supply automatic switching circuit of claim 1, wherein: the external power supply is electrically connected with the resistor R and the source electrode of the NMOS tube M2 respectively.

3. The dual power supply automatic switching circuit of claim 2, wherein: one end of the resistor R far away from the external power supply is grounded, and the drain electrode of the PMOS tube M1 and the drain electrode of the NMOS tube M2 are connected together.

4. The dual power supply automatic switching circuit of claim 1, wherein: the and gate may employ an SN74 series chip.