Switching power supply output voltage sampling circuit

Abstract

The utility model discloses an output voltage sampling circuit of a switching power supply, which comprises a voltage division buffer network used for reducing and buffering the output voltage of a circuit acquisition module and a voltage division network used for reducing the voltage output by the circuit acquisition module, wherein the voltage division buffer network and the voltage division network are respectively connected with the output end of the circuit acquisition module. The output end of the voltage division buffer network is connected with the acquisition input end of the display panel, and the output end of the voltage division network is connected with the acquisition input end of the main control board; the display panel is provided with a display acquisition module for displaying acquired information; the main control board is provided with a loop control acquisition module used for loop acquisition. According to the utility model, the two independent voltage-dividing networks are arranged on the main board for voltage reduction, one part of the voltage-dividing network output voltage enters the main control board for loop control acquisition, the other part of the voltage-dividing network output voltage enters the display panel for display acquisition after being buffered and isolated by the follower, and the voltage-dividing network output voltage and the display panel do not influence each other.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supplies, and more specifically to an output voltage sampling circuit of a switching power supply. Background Art

[0002] At present, the output voltage sampling of the switching power supply usually adopts the method of directly taking power from the output end of the circuit acquisition module, that is, one of the output voltages of the module directly enters the display panel for display acquisition, and the other directly enters the main control board for loop control acquisition. Since the display panel circuit and the main control board circuit are mostly composed of weak current signal circuits, and the two circuit boards have pluggable properties, and the output of the module is a high voltage of DC 220V, if it directly enters the display panel and the main control board, it will cause strong current to interfere with weak current, and cause harm to the human body during the plugging and unplugging process of the display panel and the main control board. Utility Model Content

[0003] The technical problem to be solved by the utility model is to provide a switching power supply output voltage sampling circuit, which uses two independent voltage-dividing networks to reduce the output voltage to avoid mutual influence between the display panel and the main control board.

[0004] In order to solve the above technical problems, the technical solutions adopted by the present utility model are as follows.

[0005] A switching power supply output voltage sampling circuit comprises a voltage-dividing buffer network for reducing the output voltage of the circuit acquisition module and a voltage-dividing network for reducing the voltage output by the circuit acquisition module, respectively connected to the output end of the circuit acquisition module, the output end of the voltage-dividing buffer network is connected to the acquisition input end of the display panel, and the output end of the voltage-dividing network is connected to the acquisition input end of the main control board; the display panel is provided with a display acquisition module for displaying acquisition information; the main control board is provided with a loop control acquisition for loop acquisition.

[0006] To further optimize the technical solution, the voltage-dividing buffer network includes a voltage-dividing resistor for dividing the module output voltage and a voltage follower for buffering and isolation. One end of the voltage-dividing resistor is connected to the output end of the circuit acquisition module, the other end of the voltage-dividing resistor is grounded, the center tap end of the voltage-dividing resistor is connected to the positive input end of the voltage follower, and the output end of the voltage follower is connected to the acquisition input end of the display panel.

[0007] To further optimize the technical solution, the voltage divider network includes a voltage divider resistor for dividing the module output voltage, one end of the voltage divider resistor is connected to the output end of the circuit acquisition module, the other end of the voltage divider resistor is grounded, and the center tap end of the voltage divider resistor is connected to the acquisition input end of the main control board.

[0008] Due to the adoption of the above technical scheme, the technical progress achieved by the utility model is as follows.

[0009] The utility model provides a switching power supply output voltage sampling circuit, which reduces the voltage by using two independent voltage-dividing networks on the main board. One part of the voltage-dividing network output voltage enters the main control board for loop control collection, and the other part of the voltage-dividing network output voltage enters the display panel for display collection after being buffered and isolated by a follower. The feedback loop and the display panel use independent voltage-dividing networks respectively, and the two do not affect each other. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural block diagram of the utility model;

[0011] Figure 2 This is a circuit diagram of the utility model. DETAILED DESCRIPTION

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0013] A switching power supply output voltage sampling circuit, combined with Figure 1 As shown, it includes a voltage divider buffer network, a display panel, a voltage divider network and a main control board. The input ends of the voltage divider buffer network and the voltage divider network are respectively connected to the output end of the circuit acquisition module. The output end of the voltage divider buffer network is connected to the signal acquisition input end of the display panel, and the output end of the voltage divider network is connected to the acquisition input end of the main control board. The display panel is provided with a display acquisition module for displaying the acquired information, and the main control board is provided with a loop control acquisition module for loop acquisition.

[0014] The circuit diagram of the utility model is as follows Figure 2 As shown, the voltage divider buffer network is used to step down and buffer the output voltage of the voltage module, including a voltage divider resistor and a voltage follower. The voltage divider resistor is used for voltage division, and the voltage follower is used for buffering and isolation. One end of the voltage divider resistor is connected to the output end of the circuit acquisition module, and the other end of the voltage divider resistor is grounded. The center tap end of the voltage divider resistor is connected to the positive input end of the voltage follower, and the output end of the voltage follower is connected to the acquisition input end of the display panel.

[0015] The voltage divider resistors of the voltage divider buffer network include NR5, NR6, NR7 and NR8 connected in series, wherein NR5 is connected to the output end of the circuit acquisition module, one end of NR8 is grounded, and the positive input end of the voltage follower is connected to the connection end of NR6 and NR7.

[0016] The voltage divider network is used to step down the voltage output by the circuit acquisition module. The voltage divider network includes a voltage divider resistor, which is used to divide the output voltage. One end of the voltage divider resistor is connected to the output end of the circuit acquisition module, the other end of the voltage divider resistor is grounded, and the center tap end of the voltage divider resistor is connected to the acquisition input end of the main control board.

[0017] The voltage-dividing resistors of the voltage-dividing network include NR9, NR10, NR11 and NR12 connected in series in sequence, wherein NR9 is connected to the output end of the circuit acquisition module, one end of NR12 is grounded, and the main control board is connected to the connection end of NR11 and NR12.

[0018] When the utility model is working, the output voltage of the circuit acquisition module is transmitted to the voltage follower after passing through the voltage-dividing resistor of the voltage-dividing buffer network, and the collected voltage signal is transmitted to the display panel to display the voltage value in real time. The second path is transmitted to the loop control circuit after passing through the voltage-dividing resistor, and the module output voltage is adjusted online in real time through the main control chip.

Claims

1. A switching power supply output voltage sampling circuit, characterized in that: It includes a voltage-dividing buffer network for reducing the output voltage of the circuit acquisition module and a voltage-dividing network for reducing the voltage output by the circuit acquisition module, which are respectively connected to the output end of the circuit acquisition module. The output end of the voltage-dividing buffer network is connected to the acquisition input end of the display panel, and the output end of the voltage-dividing network is connected to the acquisition input end of the main control board; the display panel is provided with a display acquisition module for displaying the acquired information; the main control board is provided with a loop control acquisition module for loop acquisition.

2. The switching power supply output voltage sampling circuit according to claim 1, characterized in that: The voltage-dividing buffer network includes a voltage-dividing resistor for dividing the module output voltage and a voltage follower for buffering and isolation. One end of the voltage-dividing resistor is connected to the output end of the circuit acquisition module, the other end of the voltage-dividing resistor is grounded, the center tap end of the voltage-dividing resistor is connected to the positive input end of the voltage follower, and the output end of the voltage follower is connected to the acquisition input end of the display panel.

3. The switching power supply output voltage sampling circuit according to claim 1, characterized in that: The voltage divider network includes a voltage divider resistor for dividing the module output voltage, one end of the voltage divider resistor is connected to the output end of the circuit acquisition module, the other end of the voltage divider resistor is grounded, and the center tap end of the voltage divider resistor is connected to the acquisition input end of the main control board.

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