Switch power supply input circuit with priority
Through the combination of main power supply module, backup power supply module, priority selection module and anti-reverse connection module, the problem of main and backup power priority distinction and power reverse connection in switch design is solved, and the stable operation and data security of the switch in complex environments is achieved.
Patent Information
- Application Number
- CN202422185226.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-05
- Publication Date
- 2025-07-08
- Estimated Expiration
- 2034-09-05
AI Technical Summary
In the existing switch design, the dual power input method lacks the priority distinction between main and backup power supply, and cannot automatically switch to the backup power supply after the mains power is interrupted, and there is a risk of reverse power connection, resulting in data loss or system crash.
The main power supply module, backup power supply module, priority selection module and anti-reverse connection module are adopted. Through the combination of switch tubes and diodes, the main power supply priority switching and prevent reverse connection of power supply, ensuring safe use of the power supply.
It realizes priority use of the main power supply, automatically switch to the backup power supply, prevents reverse power, and ensures that the system operates stably in complex environments, and is suitable for industrial scenarios.
Smart Images
Figure CN223079804U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of switches, in particular to a switch power supply input circuit with priorities. Background Art
[0002] With the development of network communication technology, the demand for switches, as the core devices for network connection, is increasing in various application environments. Especially in industrial environments, due to their complex and changeable working conditions, higher requirements are put forward for the reliability and stability of switches. To meet these needs, the design of switches not only needs to consider the basic data transmission performance but also pay attention to the ability to continuously work in harsh environments.
[0003] Traditional switches usually have a single power input interface, which may not guarantee the continuous operation of the system in some cases. For example, in an environment where the power supply is unstable or there is a risk of sudden power outage, a switch with a single power input may cause data loss or system crashes. Therefore, a switch design with a dual - power input function has been introduced, where one power supply serves as the main power supply and the other as the backup power supply.
[0004] Most of the dual - power input switches on the market currently adopt a power access method without distinguishing between the primary and secondary, that is, any one of the power supplies can be used as the main power supply. However, in some specific application scenarios, such as the need to still be able to operate briefly after a power outage in the mains to complete important data backup, it is necessary to clearly distinguish between the main power supply and the backup power supply, and the backup power supply often adopts a battery form to provide short - term power support. In this case, the system should give priority to using the main power supply, automatically switch to the backup power supply when the main power supply fails, and switch back to the main - power - supply - powered mode after the main power supply is restored.
[0005] In view of this, it becomes particularly crucial to propose a design scheme for an industrial switch with the function of distinguishing between the priorities of the main and backup power supplies and preventing reverse connection. Summary of the Invention
[0006] The utility model provides a switch power supply input circuit with priorities for the problems of the prior art, which can realize the switching operation of two power supplies and also achieve the purpose of preventing reverse connection to ensure the safe use of the power supply.
[0007] To solve the above technical problems, the utility model adopts the following technical solutions: It includes a main power supply module, a backup power supply module, a priority selection module, and an anti-reverse connection module; the main power supply module includes a main control switch, the backup power supply module includes a backup control switch, an external main power supply is connected to the anti-reverse connection module through the main control switch, an external backup power supply is connected to the anti-reverse connection module through the backup control switch, the output end of the anti-reverse connection module is connected to an external load, and the control end of the priority selection module is connected to the output end of the main control switch, and the priority selection module is used to control the on and off of the backup control switch.
[0008] Preferably, the main power supply module further includes a resistor R6, a resistor R7, and a capacitor C2. The main control switch is a switching transistor Q4. The external main power supply is connected to one switching end of the switching transistor Q4, the other switching end of the switching transistor Q4 is connected to the input end of the anti-reverse connection module, the control end of the switching transistor Q4 is grounded through the resistor R7, both ends of the resistor R6 are respectively connected to the external main power supply and the control end of the switching transistor Q4, and the capacitor C2 is connected in parallel with the resistor R6.
[0009] Preferably, the switching transistor Q4 is a PMOS transistor.
[0010] Preferably, the backup power supply module further includes a resistor R1, a resistor R2, and a capacitor C1. The backup control switch is a switching transistor Q1. The external backup power supply is connected to one switching end of the switching transistor Q1, the other switching end of the switching transistor Q1 is connected to the input end of the anti-reverse connection module, the control end of the switching transistor Q1 is connected to the priority selection module through the resistor R2, both ends of the resistor R1 are respectively connected to the external backup power supply and the control end of the switching transistor Q1, and the capacitor C1 is connected in parallel with the resistor R1.
[0011] Preferably, the switching transistor Q1 is a PMOS transistor.
[0012] Preferably, the priority selection module includes a switching transistor Q2, a switching transistor Q3, a resistor R3, a resistor R4, and a resistor R5. The output end of the main control switch is connected to the control end of the switching transistor Q3 through the resistor R4. The control end of the switching transistor Q3 is grounded through the resistor R5. One switching end of the switching transistor Q3 is grounded, the other switching end of the switching transistor Q3 is connected to the external backup power supply through the resistor R3. The control end of the switching transistor Q2 is connected to the other switching end of the switching transistor Q3. One switching end of the switching transistor Q2 is grounded, and the other switching end of the switching transistor Q2 is connected to the control end of the switching transistor Q1 through the resistor R2.
[0013] Preferably, both the switching transistor Q2 and the switching transistor Q3 are NPN transistors.
[0014] Preferably, the reverse connection prevention module includes a diode D1 and a diode D2. The output end of the main control switch is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to an external load. The output end of the standby control switch is connected to the anode of the diode D2, and the cathode of the diode D2 is connected to the external load.
[0015] Advantages of the present utility model:
[0016] The power supply input circuit of a switch with priority provided by the present utility model has dual power inputs, and the main power supply of the main path has a higher priority. When there is power input to the main power supply of the main path, the standby power supply is not enabled. In addition, it also has a reverse connection prevention function, which is very suitable for industrial machines and all scenarios that require redundant power or dual power supplies. Description of the drawings
[0017] Figure 1 is the signal block diagram of the present utility model;
[0018] Figure 2 is the circuit schematic diagram of the present utility model.
[0019] In Figures 1 to 2 the reference numerals include:
[0020] 1 - main power supply module, 2 - standby power supply module, 3 - priority selection module, 4 - reverse connection prevention module. Specific embodiments
[0021] For the convenience of those skilled in the art, the present utility model will be further described below in conjunction with embodiments and drawings. The content mentioned in the embodiments does not limit the present utility model. The present utility model will be described in detail below with reference to the drawings.
[0022] A power supply input circuit of a switch with priority provided in this embodiment, as Figure 1 , includes a main power supply module 1, a standby power supply module 2, a priority selection module 3, and a reverse connection prevention module 4. The main power supply module 1 includes a main control switch, the standby power supply module 2 includes a standby control switch, an external main power supply is connected to the reverse connection prevention module 4 through the main control switch, an external standby power supply is connected to the reverse connection prevention module 4 through the standby control switch, the output end of the reverse connection prevention module 4 is connected to an external load, and the control end of the priority selection module 3 is connected to the output end of the main control switch. The priority selection module 3 is used to control the on and off of the standby control switch.
[0023] Specifically, as Figure 1 and Figure 2As shown, when the external main power supply is powered, the main control switch is turned on to supply power to the external load. At this time, the priority selection module 3 controls the standby control switch not to conduct, and the standby power supply does not supply power. When the main power supply is not powered, the priority selection module 3 turns on the standby control switch to supply power to the load through the standby power supply. Therefore, this embodiment has two power supply sources and can switch the power supply according to the situation, which is suitable for use in complex environments or when the standby power supply is a battery. At the same time, it also has the function of preventing reverse connection, which can protect the safe use of the power supply and the load.
[0024] More specifically, as Figure 2 shown, it is the circuit schematic diagram of this embodiment. Among them, the main power supply module 1 further includes a resistor R6, a resistor R7, and a capacitor C2. The main control switch is a switching transistor Q4. The external main power supply is connected to one switching end of the switching transistor Q4. The other switching end of the switching transistor Q4 is connected to the input end of the reverse connection prevention module 4. The control end of the switching transistor Q4 is grounded through the resistor R7. Both ends of the resistor R6 are respectively connected to the external main power supply and the control end of the switching transistor Q4. The capacitor C2 is connected in parallel with the resistor R6. The standby power supply module 2 further includes a resistor R1, a resistor R2, and a capacitor C1. The standby control switch is a switching transistor Q1. The external standby power supply is connected to one switching end of the switching transistor Q1. The other switching end of the switching transistor Q1 is connected to the input end of the reverse connection prevention module 4. The control end of the switching transistor Q1 is connected to the priority selection module 3 through the resistor R2. Both ends of the resistor R1 are respectively connected to the external standby power supply and the control end of the switching transistor Q1. The capacitor C1 is connected in parallel with the resistor R1.
[0025] Furthermore, the priority selection module 3 includes a switching transistor Q2, a switching transistor Q3, a resistor R3, a resistor R4, and a resistor R5. The output end of the main control switch is connected to the control end of the switching transistor Q3 through the resistor R4. The control end of the switching transistor Q3 is grounded through the resistor R5. One switching end of the switching transistor Q3 is grounded. The other switching end of the switching transistor Q3 is connected to the external standby power supply through the resistor R3. The control end of the switching transistor Q2 is connected to the other switching end of the switching transistor Q3. One switching end of the switching transistor Q2 is grounded. The other switching end of the switching transistor Q2 is connected to the control end of the switching transistor Q1 through the resistor R2.
[0026] The reverse connection prevention module 4 of this embodiment includes a diode D1 and a diode D2. Both the diode D1 and the diode D2 are Schottky diodes. The output end of the main control switch is connected to the anode of the diode D1. The cathode of the diode D1 is connected to the external load. The output end of the standby control switch is connected to the anode of the diode D2. The cathode of the diode D2 is connected to the external load.
[0027] The specific connection manners of the main power supply module 1, the standby power supply module 2, the priority selection module 3, and the reverse connection prevention module 4 of this embodiment are as Figure 2As shown, where switch transistor Q1 and switch transistor Q4 are PMOS transistors, and switch transistors Q2 and Q3 are both NPN bipolar transistors. The specific working principle is as follows:
[0028] 1. When the dual power supplies are connected to the power source simultaneously, first, the two resistors R6 and R7 on the main power input V1+ path will divide the voltage. And the gate of switch transistor Q4 on the V1+ main path is connected between resistors R6 and R7. After resistors R6 and R7 divide the voltage, the gate voltage of switch transistor Q4 is approximately 80% of the input voltage. For example, if the input PoE voltage is 48V, then the voltage at the gate of switch transistor Q4 after being divided by resistors R6 and R7 is 38V. Since switch transistor Q4 is a PMOS transistor, its conduction condition is that the gate voltage is less than the source voltage of about 4.5V to conduct. At this time, the gate voltage of switch transistor Q4, which is 38V, is less than the source voltage of switch transistor Q4, which is 48V. So, switch transistor Q4 conducts at this time;
[0029] 2. When the V1+ main path conducts and starts to supply power, at this time, after the power source passes through switch transistor Q4, it will pass through resistors R4 and R5 in parallel with the main path. Resistors R4 and R5 are connected to switch transistor Q3 in the middle. When the V1+ path starts to supply power, at this time, resistors R4 and R5 will divide the voltage, providing a bias voltage to switch transistor Q3 to make it conduct. The collector of switch transistor Q3, the base of switch transistor Q2, and resistor R3 are connected to the V2+ standby power path. And the collector of switch transistor Q2 is connected to the V2+ standby power path through resistors R2 and R1. The gate of switch transistor Q1 on the V2+ standby power path is connected between resistors R1 and R2. When switch transistor Q3 conducts, it will pull down the base voltage of switch transistor Q2 to turn it off. At this time, the gate voltage of switch transistor Q1 is equal to the voltage on the V2+ standby power path, not meeting the PMOS conduction condition. So, when both V1+ and V2+ power supplies are connected to the power source, the V2+ standby power path will not supply power;
[0030] 3. When the power on the V1+ main path is lost or not connected, and only the power on the V2+ standby power path is connected, at this time, resistor R3 provides a bias voltage to the base of switch transistor Q2 to make it conduct. After switch transistor Q2 conducts, resistors R1 and R2 divide the voltage, making the gate voltage of switch transistor Q1 on the V2+ standby power path be 80% of the voltage on the V2+ standby power path, meeting the PMOS conduction condition, and the V2+ standby power path starts to supply power;
[0031] 4. Since switch transistors Q1 and Q4 have built-in diodes, and diodes D1 and D2 are connected after the dual power supplies, when the positive and negative poles of the power source are reversed, the circuit cannot supply power, achieving the effect of reverse connection prevention, which is safe and reliable.
[0032] In this embodiment, by controlling the conduction or disconnection of the switching transistors Q1, Q4, Q2, and Q3, the selection of dual power supplies is achieved. The circuit structure principle is simple, easy to control, stable and reliable, and is more conducive to maintenance, making it suitable for use in complex environments or when the backup power supply is a battery. Further, the anti-reverse connection of the two power supplies is achieved through the diodes D1 and D2, ensuring the safety of power supply application, preventing the user from reversing the positive and negative poles of the power supply and causing damage to the subsequent circuit, with higher safety.
[0033] The above description is only a preferred embodiment of the present invention and does not impose any form of limitation on the present invention. Although the present invention is disclosed above in a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art, without departing from the scope of the technical solution of the present invention, when making some changes or modifications using the above-disclosed technical content into equivalent embodiments of equivalent changes, but as long as they do not depart from the content of the technical solution of the present invention, any simple modification, equivalent change, and modification made to the above embodiments according to the technical means of the present invention shall fall within the scope of the technical solution of the present invention.
Claims
1. A switch power supply input circuit with priorities, characterized in that: It includes a main power supply module, a backup power supply module, a priority selection module, and an anti-reverse connection module; the main power supply module includes a main control switch, the backup power supply module includes a backup control switch, an external main power supply is connected to the anti-reverse connection module through the main control switch, an external backup power supply is connected to the anti-reverse connection module through the backup control switch, the output end of the anti-reverse connection module is connected to an external load, and the control end of the priority selection module is connected to the output end of the main control switch, and the priority selection module is used to control the on and off of the backup control switch.
2. The power supply input circuit of a switch with priority according to claim 1, wherein: The main power supply module further includes a resistor R6, a resistor R7, and a capacitor C2. The main control switch is a switching transistor Q4. The external main power supply is connected to one switching end of the switching transistor Q4, the other switching end of the switching transistor Q4 is connected to the input end of the anti-reverse connection module, the control end of the switching transistor Q4 is grounded through the resistor R7, both ends of the resistor R6 are respectively connected to the external main power supply and the control end of the switching transistor Q4, and the capacitor C2 is connected in parallel with the resistor R6.
3. The power supply input circuit of a switch with priority according to claim 2, characterized in that: The switching transistor Q4 is a PMOS transistor.
4. The input circuit for power supply of a switch with priorities according to claim 1, wherein: The backup power supply module further includes a resistor R1, a resistor R2, and a capacitor C1. The backup control switch is a switching transistor Q1. The external backup power supply is connected to one switching end of the switching transistor Q1, the other switching end of the switching transistor Q1 is connected to the input end of the anti-reverse connection module, the control end of the switching transistor Q1 is connected to the priority selection module through the resistor R2, both ends of the resistor R1 are respectively connected to the external backup power supply and the control end of the switching transistor Q1, and the capacitor C1 is connected in parallel with the resistor R1.
5. The input circuit for powering a switch with priorities according to claim 4, wherein: The switching transistor Q1 is a PMOS transistor.
6. The input circuit for powering a switch with priority according to claim 4, wherein: The priority selection module includes a switching transistor Q2, a switching transistor Q3, a resistor R3, a resistor R4, and a resistor R5. The output end of the main control switch is connected to the control end of the switching transistor Q3 through the resistor R4. The control end of the switching transistor Q3 is grounded through the resistor R5. One switching end of the switching transistor Q3 is grounded, the other switching end of the switching transistor Q3 is connected to the external backup power supply through the resistor R3. The control end of the switching transistor Q2 is connected to the other switching end of the switching transistor Q3. One switching end of the switching transistor Q2 is grounded, and the other switching end of the switching transistor Q2 is connected to the control end of the switching transistor Q1 through the resistor R2.
7. The power supply input circuit of a switch with priority according to claim 6, characterized in that: Both the switching transistor Q2 and the switching transistor Q3 are NPN transistors.
8. The power supply input circuit of a switch with priority according to claim 1, characterized in that: The anti-reverse connection module includes a diode D1 and a diode D2. The output end of the main control switch is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the external load; the output end of the backup control switch is connected to the anode of the diode D2, and the cathode of the diode D2 is connected to the external load.