CN219875136U

CN219875136U - Dual-power supply switching circuit for battery and internal power supply

Info

Publication number: CN219875136U
Application number: CN202320687363.1U
Authority: CN
Inventors: 姜晓东
Original assignee: AVIC Huadong Photoelectric Co Ltd
Current assignee: AVIC Huadong Photoelectric Co Ltd
Priority date: 2023-03-30
Filing date: 2023-03-30
Publication date: 2023-10-20
Anticipated expiration: 2033-03-30

Abstract

The embodiment of the utility model provides a battery and internal power supply dual-power supply switching circuit, and belongs to the technical field of dual-power supply equipment. The battery and internal power supply dual-power supply switching circuit includes: an internal power supply port, a battery supply port and a power output port; the internal power supply port is connected with the power output port through a plurality of diodes; the battery power supply port is connected with the power supply output port through an MOS tube; the internal power supply port is connected with an acquisition module and is used for acquiring real-time voltages of the internal power supply port and the battery power supply port. The scheme of the utility model is suitable for double power supply switching under various voltage states, the battery supplies power to the load through the MOS switch, the voltage drop generated by the method is small, the power consumption of the battery can be saved, the circuit is simple, and the cost is low.

Description

Dual-power supply switching circuit for battery and internal power supply

Technical Field

The utility model relates to the technical field of double power supply equipment, in particular to a battery and internal power supply double power supply switching circuit.

Background

In order to ensure stable operation of loads, a plurality of power supply modes exist in the same load at present, wherein the power supply modes serve as mutually redundant power supply modes, when one power supply mode works, other power supplies are in standby state at the time, and when the current power supply mode fails or is disconnected, the other power supply modes are used for intervening in power supply. In particular, since the stable operation of devices such as a control module, a display module, and a collection module is directly related to the stable operation of large devices to be controlled, it is quite common to provide a plurality of power supply modes on these devices.

In the dual power supply apparatus, a great concern is required about how to implement automatic switching of power supply and how to ensure fast and stable switching action, and further, it is required to ensure that, regardless of the power supply mode, it is required to ensure sufficiently stable operation performance. There are many existing automatic switching circuits for two-way power supply. The common cathode diode is generally adopted to realize the power supply switching function, and the circuit is simple to build, low in cost and capable of preventing voltage from reversing. However, this approach has the great disadvantage of a large voltage drop, which is disadvantageous for low voltage battery powered applications. The low-voltage battery is very commonly applied to the equipment such as a very common control module, a display module, an acquisition module and the like, so that the existing dual-power supply switching scheme cannot meet the dual-power supply switching under the application scene of the low-voltage battery. Aiming at the problems of large voltage drop and unfavorable use of low-voltage battery power supply in the existing double-power supply switching scheme, a double-power supply switching circuit of a battery and an internal power supply needs to be created.

Disclosure of Invention

The embodiment of the utility model aims to provide a battery and internal power supply dual-power supply switching circuit, which solves the problems of large voltage drop and unfavorable use of low-voltage battery power supply existing in the existing dual-power supply switching scheme.

In order to achieve the above object, an embodiment of the present utility model provides a battery and internal power supply dual-power supply switching circuit, including: an internal power supply port, a battery supply port and a power output port; the internal power supply port is connected with the power output port through a plurality of diodes; the battery power supply port is connected with the power supply output port through an MOS tube; the internal power supply port is connected with an acquisition module and is used for acquiring real-time voltages of the internal power supply port and the battery power supply port.

Optionally, all diodes between the internal power supply port and the power output port are connected in series.

Optionally, all diode cathodes between the internal power supply port and the power output port are directed towards the power output.

Optionally, a diode parameter between the internal power supply port and the power output port is determined by the internal power supply port voltage and the power output port voltage; the diode parameters include: the number of diodes and the type of diodes.

Optionally, the battery power supply port is connected to the drain electrode of the MOS transistor.

Optionally, the power output port is connected to the source electrode of the MOS tube.

Optionally, the grid electrode of the MOS tube is connected with the internal power supply port; and the MOS tube is turned off at a high level and turned on at a low level.

Optionally, the acquisition module includes: and the internal power supply port voltage acquisition circuit is connected between the internal power supply port and the grid electrode of the MOS tube.

Optionally, the acquisition module further includes: and the battery power supply port voltage acquisition circuit is connected between the battery power supply port and the source electrode of the MOS tube.

Optionally, the internal power supply port voltage acquisition circuit and the battery supply port voltage acquisition circuit are both constructed based on voltage dividing resistors.

Through the technical scheme, the utility model provides the double-power supply switching circuit for the battery and the internal power supply, which is suitable for double-power supply switching under various voltage states, the battery supplies power to a load through the MOS switch, the voltage drop generated by the method is small, the power consumption of the battery can be saved, the circuit is simple, and the cost is low; the internal power supply end can reduce the voltage through the series diode, so that the voltage of the load end is lower, and accidents caused by heating or explosion of the battery possibly caused by the fact that the load end enters the battery end through the internal parasitic diode of the MOS are prevented. .

Additional features and advantages of embodiments of the utility model will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of embodiments of the utility model and are incorporated in and constitute a part of this specification, illustrate embodiments of the utility model and together with the description serve to explain, without limitation, the embodiments of the utility model. In the drawings:

fig. 1 is a circuit diagram of a battery and internal power supply dual-supply switching circuit according to an embodiment of the present utility model.

Detailed Description

The following describes the detailed implementation of the embodiments of the present utility model with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the utility model, are not intended to limit the utility model.

In the embodiments of the present utility model, unless otherwise indicated, terms such as "upper, lower, left, and right" and "upper, lower, left, and right" are used generally referring to directions or positional relationships based on those shown in the drawings, or those conventionally used in the use of the inventive products.

The terms "first," "second," "third," and the like are used merely to distinguish between descriptions and are not to be construed as indicating or implying relative importance.

The terms "horizontal," "vertical," "overhang," and the like do not denote that the component is required to be absolutely horizontal, vertical, or overhang, but may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

Furthermore, the terms "substantially," "essentially," and the like, are intended to be limited to the precise form disclosed herein and are not necessarily intended to be limiting. For example: the term "substantially equal" does not merely mean absolute equal, but is difficult to achieve absolute equal during actual production and operation, and generally has a certain deviation. Thus, in addition to absolute equality, "approximately equal to" includes the above-described case where there is a certain deviation. In other cases, the terms "substantially", "essentially" and the like are used in a similar manner to those described above unless otherwise indicated.

In the description of the present utility model, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In the dual power supply apparatus, a great concern is required about how to implement automatic switching of power supply and how to ensure fast and stable switching action, and further, it is required to ensure that, regardless of the power supply mode, it is required to ensure sufficiently stable operation performance. There are many existing automatic switching circuits for two-way power supply. The common cathode diode is generally adopted to realize the power supply switching function, and the circuit is simple to build, low in cost and capable of preventing voltage from reversing. However, this approach has the great disadvantage of a large voltage drop, which is disadvantageous for low voltage battery powered applications. The low-voltage battery is very commonly applied to the equipment such as a very common control module, a display module, an acquisition module and the like, so that the existing dual-power supply switching scheme cannot meet the dual-power supply switching under the application scene of the low-voltage battery.

Aiming at the problems that the existing double-power-supply switching scheme has large voltage drop and is not beneficial to the use of low-voltage battery power supply, the scheme of the utility model provides a double-power-supply switching device for batteries and internal power supplies, which is suitable for double-power-supply switching under various voltage states, and the batteries supply power to loads through MOS switches; the internal power supply end can step down through the series diode, so that the voltage of the load end is lower, and the load end is prevented from entering the battery end through the internal parasitic diode of the MOS, and accidents caused by heating or explosion of the battery can be possibly caused.

Fig. 1 is a system configuration diagram of a battery and internal power supply dual power supply switching device according to an embodiment of the present utility model. As shown in fig. 1, an embodiment of the present utility model provides a battery and internal power source dual-power switching device, including: an internal power supply port, a battery supply port and a power output port; the internal power supply port is connected with the power output port through a plurality of diodes; the battery power supply port is connected with the power supply output port through an MOS tube; the internal power supply port is connected with an acquisition module and is used for acquiring the real-time voltage of the internal power supply port and controlling the MOS tube to be conducted when the real-time voltage of the internal power supply port is 0.

In the embodiment of the utility model, the battery is connected to the voltage output end through the MOS tube, the internal power supply is connected to the voltage output end through the diode, and the voltage output end is connected with the internal power supply through the diode step-down and also connected with the battery through the MOS switch output. In the technical scheme, the internal power supply is superior to the battery, and when the internal power supply exists, the load is powered by the internal power supply; and conversely, when the internal power supply is detected to have no voltage, controlling the MOS of the battery switch to be conducted, and supplying power to the load by the battery. The design is flexible in power supply switching, can improve the utilization of the battery, and can achieve the time delay of battery power supply; the internal power supply is connected reversely through the diode, so that the voltage reduction effect is achieved, the current at the voltage output end is prevented from flowing back to the battery end, the voltage reversal can be effectively prevented, and the battery is protected.

Preferably, the power supply priority of the internal power supply port is higher than the power supply priority of the battery supply port.

In the embodiment of the utility model, because the battery is powered by pre-stored electricity, the battery is only used for emergency in the state that the internal power supply is powered off, and the stable power supply time is limited, the battery can only be used as an emergency scheme. Based on this, the main power supply mode of the dual power supply switching device supplies power to the internal power supply, and battery power supply is only intervened when the internal power supply ages. Based on this, the MOS transistor is in an off state (off between the battery power supply port and the power supply output port) in a normal power supply state of the internal power supply, and is in an on state when the voltage of the internal power supply is 0.

MOS, an abbreviation for MOSFET. MOSFET metal-oxide semiconductor field effect transistor, referred to as metal oxide semiconductor field effect transistor. The MOS tube has three pin names, namely G: gate; s: source; d: drain of drain. According to channel classification, field effect transistors are classified into PMOS (P-channel type) and NMOS (N-channel type) transistors. The method has the following characteristics:

the input impedance is very high, and because the grid electrode of the MOS tube is provided with an insulating film oxide and can reach hundreds of millions of ohms, the input of the MOS tube hardly takes current, and the MOS tube can be used as an electronic switch. The on-resistance is low, the resistance of a few milliohms can be realized, and the conduction loss is extremely low. The switching speed is high, the switching loss is low, and the method is particularly suitable for PWM output modes. Low power consumption, stable performance, strong radiation resistance, low manufacturing cost, small use area and high integration degree.

The scheme of the utility model utilizes the characteristics of the MOS tube and realizes the rapid switching of the dual power supply modes. And because the internal power supply has obvious high level and 0 voltage when the internal power supply supplies power normally and stops supplying power, the MOS tube can be automatically switched on and off based on the changed voltage, so that the passive double-power-supply mode switching is realized.

Preferably, all diodes between the internal power supply port and the power output port are connected in series.

In the embodiment of the utility model, for low-voltage electric equipment, the power consumption voltage is usually about 3.6v, and the power supply voltage is about 5v, and other power consumption conditions exist, however, the voltage of the internal power supply cannot be guaranteed to be completely matched with the required voltage of all the electric equipment all the time, and based on the fact, the power supply voltage of the internal power supply needs to be adjusted to the required voltage of the corresponding electric equipment. According to the scheme, a plurality of diodes are connected in series between an internal power supply port and the power output port, and the voltage is regulated to the target voltage through the plurality of diodes connected in series.

A diode is a semiconductor device that allows current flow in one direction and restricts current flow in the other. There is a voltage drop effect for the diode, which basically refers to a forward bias voltage drop. When a current passes through it, it occurs in a diode present in the circuit. This forward bias voltage drop is a result of the depletion region formed by the PN junction under the applied voltage. According to the scheme, the voltage drop characteristic of the diode is fully utilized, and the power supply voltage of the internal power supply is reduced to the target voltage of power utilization.

Preferably, all diode cathodes between the internal power supply port and the power output port are directed towards the power output.

In embodiments of the present utility model, the diode drop is referred to as essentially a forward biased drop, as known above. When a current passes through it, it occurs in a diode present in the circuit. This forward bias voltage drop is a result of the depletion region formed by the PN junction under the applied voltage. Therefore, to achieve a voltage reduction from the internal power supply port to the power output port, it is necessary to ensure that all diode cathodes are directed towards the power output.

Preferably, a diode parameter between the internal power supply port and the power output port is determined by the internal power supply port voltage and the power output port voltage; the diode parameters include: the number of diodes and the type of diodes.

In embodiments of the present utility model, the voltage drop across different diodes is different. Typically, for a small silicon diode, its voltage ranges from 0.6 to 0.7 volts. For a schottky diode, the voltage drop has a value of 0.2 volts. For a light emitting diode or LED, the voltage drop ranges from 1.4 to 4 volts. The voltage drop of the germanium diode is 0.25-0.3 volt. Therefore, when other target voltages exist in the electric equipment, voltage constant reduction is needed to be carried out through serial connection of different diode numbers and types, so that the voltage of the power supply output port is ensured to be the same as the target voltage of the electric equipment, and stable operation of the electric equipment is ensured.

Preferably, the battery power supply port is connected to the drain electrode of the MOS tube; and the power supply output port is connected with the source electrode of the MOS tube.

Preferably, the grid electrode of the MOS tube is connected with the internal power supply port; and the MOS tube is turned off at a high level and turned on at a low level.

In the embodiment of the utility model, the switching condition of the MOS tube is as follows: n channel: when Vg > Vs, vgs > Vgs (th) are conducted; p channel: vg < Vs, vgs < Vgs (th) at turn-on. Where Vgs is the control voltage of the gate and Vgs (th) is the turn-on voltage. Because the MOS tube switch control is carried out by the power supply voltage of the internal power supply, the grid electrode of the MOS tube is required to be connected with the power supply port of the internal power supply. When the voltage of the grid electrode is 0, namely when the power supply of the internal power supply is disconnected, the MOS tube is required to be conducted, namely the P-MOS tube is selected according to the scheme of the utility model.

Preferably, the collection module is further configured to monitor a voltage of a battery power supply port, and control the MOS transistor to be turned off when the voltage of the battery power supply port is lower than a preset voltage threshold.

Preferably, the acquisition module comprises: the internal power supply port voltage acquisition circuit is connected between the internal power supply port and the MOS tube grid electrode; and the battery power supply port voltage acquisition circuit is connected between the battery power supply port and the MOS tube source electrode.

Preferably, the internal power supply port voltage acquisition circuit and the battery power supply port voltage acquisition circuit are both constructed based on voltage dividing resistors.

In one possible embodiment, the internal power supply 5V is stepped down in series to the output voltage 3.6V by two diodes D7, D8 while preventing the reversal of the output voltage; the internal power supply voltage of 5V monitors the voltage value through a voltage dividing resistor, when the power failure of the 5V power supply is detected, the MOS tube Q19 is conducted, the power is supplied to a load by a battery, and the voltage drop is reduced through MOS, so that the battery loss is reduced; meanwhile, the voltage of the battery can be monitored through the voltage dividing resistors R9 and R10, when the voltage of the battery is lower than 3V, the single-chip microcomputer is used for supplying power to EN1 through a high level, the MOS battery is turned off to protect the battery, the battery voltage is prevented from being too low, the current at the voltage output end flows back to the battery end, the voltage is effectively prevented from reversing, the battery is prevented from being charged, heated and exploded, and the battery is protected.

In the embodiment of the utility model, the battery is connected to the voltage output end through the MOS, the internal power supply is connected to the voltage output end through the diode, and the voltage output end is connected with the internal power supply through the diode step-down and also connected with the battery through the MOS switch output. In the scheme of the utility model, the internal power supply is superior to the battery, and when the internal power supply exists, the load is powered by the internal power supply; and conversely, when the internal power supply is detected to have no voltage, controlling the MOS of the battery switch to be conducted, and supplying power to the load by the battery. The design is flexible in power supply switching, can improve the utilization of the battery, and can achieve the time delay of battery power supply; the internal power supply is connected reversely through the diode, so that the voltage reduction effect is achieved, the current at the voltage output end is prevented from flowing back to the battery end, the voltage reversal can be effectively prevented, and the battery is protected.

In the embodiment of the utility model, the on-off of the battery is controlled through the field effect transistor, so that the working current is effectively reduced, the voltage loss of the battery is reduced, and the utilization rate of the battery is improved. The internal power supply can effectively prevent the voltage from reversing through the diode connected in series, meanwhile, the output voltage is reduced, the current at the voltage output end is prevented from flowing back to the battery end, the voltage is effectively prevented from reversing, the battery is prevented from being charged, heated and exploded, and the battery is protected. The foregoing details of the optional implementation of the embodiment of the present utility model have been described in detail with reference to the accompanying drawings, but the embodiment of the present utility model is not limited to the specific details of the foregoing implementation, and various simple modifications may be made to the technical solution of the embodiment of the present utility model within the scope of the technical concept of the embodiment of the present utility model, and these simple modifications all fall within the protection scope of the embodiment of the present utility model.

In addition, the specific features described in the above embodiments may be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, various possible combinations of embodiments of the present utility model are not described in detail.

Those skilled in the art will appreciate that all or part of the steps in implementing the methods of the embodiments described above may be implemented by a program stored in a storage medium, including instructions for causing a single-chip microcomputer, chip or processor (processor) to perform all or part of the steps of the methods of the embodiments described herein. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (RAM, random Access Memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.

In addition, any combination of various embodiments of the present utility model may be performed, so long as the concept of the embodiments of the present utility model is not violated, and the disclosure of the embodiments of the present utility model should also be considered.

Claims

1. The utility model provides a battery and internal power source dual supply switching circuit which characterized in that, battery and internal power source dual supply switching circuit includes:

an internal power supply port, a battery supply port and a power output port;

the internal power supply port is connected with the power output port through a plurality of diodes;

the battery power supply port is connected with the power supply output port through an MOS tube;

the internal power supply port is connected with an acquisition module and is used for acquiring real-time voltages of the internal power supply port and the battery power supply port.

2. The battery and internal power dual supply switching circuit of claim 1, wherein all diodes between the internal power supply port and the power output port are connected in series.

3. The dual battery and internal power supply switching circuit of claim 1, wherein all diode cathodes between the internal power supply port and the power output port are directed toward the power output.

4. The battery and internal power dual supply switching circuit of claim 1, wherein a diode parameter between the internal power supply port and the power output port is determined by the internal power supply port voltage and the power output port voltage;

the diode parameters include:

the number of diodes and the type of diodes.

5. The dual battery and internal power supply switching circuit of claim 1, wherein the battery power supply port is connected to the drain of the MOS transistor.

6. The dual battery and internal power supply switching circuit of claim 1, wherein the power output port is connected to a source of the MOS transistor.

7. The dual battery and internal power supply switching circuit of claim 1, wherein a gate of the MOS transistor is connected to the internal power supply port;

and the MOS tube is turned off at a high level and turned on at a low level.

8. The battery and internal power supply dual supply switching circuit of claim 1, wherein the acquisition module comprises:

and the internal power supply port voltage acquisition circuit is connected between the internal power supply port and the grid electrode of the MOS tube.

9. The battery and internal power dual supply switching circuit of claim 1, wherein the acquisition module further comprises:

and the battery power supply port voltage acquisition circuit is connected between the battery power supply port and the source electrode of the MOS tube.

10. The dual battery and internal power supply switching circuit according to claim 8 or 9, wherein the internal power supply port voltage acquisition circuit and the battery supply port voltage acquisition circuit are each constructed based on a voltage dividing resistor.