CN210246388U

CN210246388U - Double-direct-current power supply fast switching circuit based on field effect transistor

Info

Publication number: CN210246388U
Application number: CN201921290010.8U
Authority: CN
Inventors: Bowen Tian; 田博文; Huaiquan Liu; 刘怀泉; Jinning Gao; 高金宁
Original assignee: Shandong Chaoyue CNC Electronics Co Ltd
Current assignee: Shandong Chaoyue CNC Electronics Co Ltd
Priority date: 2019-08-10
Filing date: 2019-08-10
Publication date: 2020-04-03
Anticipated expiration: 2029-08-10

Abstract

The utility model discloses a two DC power supply fast switch-over circuit based on field effect transistor, change DC power adapter including exchanging, stabilize DC lead accumulator and power adapter and the common power switching circuit who connects of lead accumulator, power adapter ' S direct current output connects power switching circuit ' S pin 1 of connector P1, connector P1 ' S pin 3 connects lead accumulator ' S direct current output, connector P1 ' S pin 2 connects the input common ground circuit, connector P1 ' S pin 1 connects field effect transistor Q1 ' S drain electrode D, field effect transistor Q1 ' S source electrode S connects connector P2 ' S pin 1, connector P2 exports stable DC power supply; the utility model discloses a control of power supply switching circuit break-make state that the circuit was accomplished and is constituteed to field effect transistor to the realization realizes the fast switch over power supply mode to the stable power supply of server equipment, thereby guarantees that equipment operates for a long time, steadily.

Description

Double-direct-current power supply fast switching circuit based on field effect transistor

Technical Field

The utility model relates to an analog circuit technical field, concretely relates to two DC power supply fast switch over circuit based on field effect transistor.

Background

Nowadays, in many industries such as telecommunication, finance, industrial control and the like, many devices such as switches, servers and the like are required to work all the day. At present, server equipment is more and more widely applied, most of the server equipment uses 220V alternating current as a power supply source, and a small amount of mobile server equipment adopts lead storage batteries for power supply. The power supply by adopting 220V alternating current has the risk of power failure, and the long-time endurance cannot be ensured by adopting lead storage batteries for power supply, so that the cost is extremely high, and the large-scale application cannot be realized. The two power supply modes are matched for use, the corresponding power supply is selected according to the requirement, the power supply can be switched rapidly, and a foundation can be laid for the server equipment to work durably. Taking a dc server device as an example, an external adapter is mostly adopted, and 220V ac is used as a power supply source. However, once a power failure accident occurs, the server device is down, which may cause data loss and system crash. Even if the power supply is switched to a standby generator or a lead storage battery for power supply, the circuit can be burnt out if the power supply switching circuit of the traditional portable notebook computer is used for power supply due to the large working current of the server equipment; if a high-power electromagnetic relay is adopted for switching, a power supply vacuum period can occur in the switching process, and the equipment can be restarted after power failure. How to realize the rapid switching of the heavy current and the double power supplies and ensure the stable operation of the server equipment is a difficult problem to be solved urgently.

SUMMERY OF THE UTILITY MODEL

To the problem that exists among the prior art, the utility model aims to provide a two DC power supply fast switch over circuit based on field effect transistor.

The utility model provides a technical scheme that its technical problem adopted is: a field effect transistor-based double-direct-current power supply fast switching circuit comprises an alternating-current to direct-current power adapter, a lead storage battery for stabilizing direct current, and a power supply switching circuit connected with the power adapter and the lead storage battery together, the direct current output of the power adapter is connected with a pin 1 of a connector P1 of the power switching circuit, a pin 3 of a connector P1 is connected with the direct current output of the lead storage battery, a pin 2 of a connector P1 is connected with the input common ground circuit, a pin 1 of a connector P1 is connected with a drain D of a field effect transistor Q1, a source S of the field effect transistor Q1 is connected with the pin 1 of a connector P2, a gate G of the field effect transistor Q1 is connected with a drain D of a field effect transistor Q2 and a drain D of the field effect transistor Q3, a source S of the field effect transistor Q2 is connected with a pin 3 of a connector P1, a source S of the field effect transistor Q3 is connected with the pin 1 of a connector P2, and the connector.

Specifically, two capacitors are connected in parallel between the pin 1 and the pin 2 of the connector P1 to form a common ground circuit.

Specifically, a capacitor is connected between the pin 1 and the pin 2 of the connector P2 to form a grounding circuit.

Specifically, pin 1 of the connector P1 is connected to the gate G of the fet Q2 and the fet Q3 through the resistor R1, and the rear end is connected to the resistor R2 and then grounded.

Specifically, the field-effect tube Q1, the field-effect tube Q2 and the field-effect tube Q3 adopt a P-channel enhanced insulated gate type, the type is IRF-5210, the conduction impedance of the IRF-5210 is 0.06 ohm, the maximum conduction current is 40 amperes, the power reaches 200 watts, and the turn-on voltage is-2V.

The utility model discloses following beneficial effect has:

the utility model discloses a power adapter and lead accumulator's DC power supply is connected to power supply switching circuit's input respectively, and the output directly is the power supply of DC server equipment, through two kinds of DC power supply's of input access condition, and the control to the power switching circuit break-make state that field effect tube constitutes is accomplished to the circuit to the realization realizes the stable power supply to server equipment, realizes fast switch over power supply mode, thereby guarantees that equipment is permanent, operates steadily.

Drawings

Fig. 1 is a schematic structural diagram of a dual dc power supply fast switching circuit based on a field effect transistor.

Fig. 2 is a circuit schematic diagram of a field effect transistor-based dual dc power supply fast switching circuit.

Fig. 3 is a working flow chart of a field effect transistor-based double direct current power supply fast switching circuit.

Detailed Description

The technical solution in the embodiments of the present invention will be described in further detail in the following clearly and completely with reference to the accompanying drawings in the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

As shown in fig. 1-2, a dual dc power supply fast switching circuit based on fet includes an ac to dc power adapter, the lead storage battery for stabilizing direct current and the power supply switching circuit commonly connected with the power supply adapter and the lead storage battery are characterized in that a direct current output of the power supply adapter is connected with a pin 1 of a connector P1 of the power supply switching circuit, a pin 3 of a connector P1 is connected with a direct current output of the lead storage battery, a pin 2 of a connector P1 is connected with an input common ground circuit, a pin 1 of a connector P1 is connected with a drain D of a field effect tube Q1, a source S of a field effect tube Q1 is connected with a pin 1 of a connector P2, a grid G of the field effect tube Q1 is connected with a drain D of the field effect tube Q2 and a drain D of the field effect tube Q3, a source S of the field effect tube Q2 is connected with a pin 3 of a connector P1, a source S of a field effect tube Q3 is connected.

Two capacitors are connected in parallel between the pin 1 and the pin 2 of the connector P1 to form a common ground circuit; a capacitor is connected between the pin 1 and the pin 2 of the connector P2 to form a grounding circuit; pin 1 of connector P1 is connected with gate G of FET Q2 and FET Q3 through resistor R1, and the rear end is grounded after being connected with resistor R2; the field-effect transistor Q1, the field-effect transistor Q2 and the field-effect transistor Q3 adopt a P-channel enhanced insulated gate type, the type is IRF-5210, the conduction impedance of the IRF-5210 is 0.06 ohm, the maximum conduction current is 40 amperes, the power reaches 200 watts, and the starting voltage is-2V.

As shown in fig. 2-3, taking the dual dc 12V power supply as an example, the principle that the fet has a small on-resistance, a large off-resistance, and a very short on-off time is used to connect the 12V dc U1 of the 220V power adapter and the 12V dc U2 of the lead-acid battery to the input end of the fet circuit, and the output end directly supplies power to the dc server device. When both the U1 and the U2 are connected, the circuit selects a U1 (namely a 220V power adapter) power supply mode, and when 220V alternating current is disconnected due to external reasons (such as sudden power failure), the power supply mode is automatically and quickly switched to a U2 (namely a 12V lead storage battery) power supply mode, so that the equipment can operate stably for a long time.

When the 220V power adapter and the 12V lead storage battery supply power simultaneously, the grid-source voltage of the field-effect transistor Q2 is larger than the starting voltage, and the field-effect transistor Q2 is in a cut-off state. Therefore, when the two power supply modes are simultaneously accessed, the power supply is only carried out by the 220V power adapter.

When the 220V power adapter is suddenly disconnected, the grid voltage of the field effect transistor Q2 is in a descending trend. When the gate voltage of the field effect transistor Q2 is less than 10V, Q2 is in the on state. As the gate voltage of the fet Q2 continues to drop, the drain voltage gradually rises; at this time, the gate-source voltage of the field effect transistor Q1 gradually increases, and the on effect thereof deteriorates until it is turned off. The source voltage of the fet Q3 gradually increases, the gate voltage of the fet Q3 is already small, and at this time, the gate-source voltage of the fet Q3 is smaller than its turn-on voltage, and the fet Q3 is in a conducting state. Thus, the lead storage battery power supply path formed by the field effect transistor Q2 and the field effect transistor Q3 is conducted.

The on-off time of the field effect tube is in nanosecond level, and instantaneous switching of power supply of the 220V power adapter and the lead storage battery is achieved. Although the potential of the port of the connector P2 fluctuates instantaneously, the power module of the back-end server has the characteristic of wide voltage input, and therefore, the operation of the server is not influenced.

The utility model discloses not be limited to above-mentioned embodiment, anybody should learn the structural change who makes under the teaching of the utility model, all with the utility model discloses have the same or close technical scheme, all fall into the utility model discloses an within the protection scope.

The technology, shape and construction parts which are not described in detail in the present invention are all known technology.

Claims

1. A field effect transistor-based double-direct-current power supply fast switching circuit is characterized by comprising an alternating-current to direct-current power adapter, a lead storage battery for stabilizing direct current and a power supply switching circuit which is connected with the power adapter and the lead storage battery together, the direct current output of the power adapter is connected with a pin 1 of a connector P1 of the power switching circuit, a pin 3 of a connector P1 is connected with the direct current output of the lead storage battery, a pin 2 of a connector P1 is connected with the input common ground circuit, a pin 1 of a connector P1 is connected with a drain D of a field effect transistor Q1, a source S of the field effect transistor Q1 is connected with the pin 1 of a connector P2, a gate G of the field effect transistor Q1 is connected with a drain D of a field effect transistor Q2 and a drain D of the field effect transistor Q3, a source S of the field effect transistor Q2 is connected with a pin 3 of a connector P1, a source S of the field effect transistor Q3 is connected with the pin 1 of a connector P2, and the connector.

2. The fet-based dual dc power supply fast switching circuit of claim 1, wherein two capacitors are connected in parallel between pin 1 and pin 2 of the connector P1 to form a common ground circuit.

3. The fet-based dual dc power supply fast switching circuit of claim 1, wherein a capacitor is connected between pin 1 and pin 2 of the connector P2 to form a ground circuit.

4. The FET-based dual DC power supply fast switching circuit as claimed in claim 1, wherein pin 1 of the connector P1 is connected to the gate G of FET Q2 and FET Q3 through a resistor R1, and the rear end of the connector is connected to the ground after being connected to a resistor R2.

5. The field effect transistor-based double direct-current power supply fast switching circuit as claimed in claim 1, wherein the field effect transistor Q1, the field effect transistor Q2 and the field effect transistor Q3 are of a P-channel enhancement type insulated gate type, the type is IRF-5210, the on-resistance of the IRF-5210 is 0.06 ohm, the maximum on-current is 40 amperes, the power reaches 200 watts, and the turn-on voltage is-2V.