CN-224203289-U - Current sampling circuit capable of switching power through software

Abstract

The utility model discloses a current sampling circuit capable of switching power through software, which comprises a conversion unit, an isolation amplifier U2 and a switching power unit, wherein the conversion unit is used for acquiring current and converting the current into a voltage signal to be uploaded, the isolation amplifier U2 is used for amplifying the voltage signal to be output, the switching power unit is used for amplifying the amplified voltage signal after adjusting the amplification factor of a later-stage amplifying circuit, the switching power unit comprises resistors R1, R3, R5, R8, R10, R11, optical relays U3, U4, U5 and U6, one ends of the resistors R1, R3 and R5 are connected in parallel and then are connected with the isolation amplifier U2, one ends of the resistors R8, R10 and R11 are connected in parallel and then are connected with the isolation amplifier U2, the optical relay U3 is connected between the resistors R1 and R3, the optical relay U4 is connected between the optical relay U5 and the optical relay U3, the optical relay U5 is connected between the optical relay U6 and the optical relay U8, and the optical relay U6 is connected between the optical relay U10 and the optical relay U11. The utility model discloses a set up the converter power through control panel, can reduce the influence that misoperation brought.

Inventors

• PAN WENJIE

Assignees

• 深圳硅山技术有限公司

Dates

Publication Date

20260505

Application Date

20250513

Claims (6)

1. 1. A current sampling circuit for switching power by software, comprising: the conversion unit is used for acquiring current, converting the current into a voltage signal and uploading the voltage signal; the isolation amplifier U2 is used for amplifying the voltage signal and outputting the amplified voltage signal; The switching power unit is used for amplifying the amplified voltage signal after adjusting the amplification factor of the post-stage amplifying circuit; The switching power unit comprises resistors R1, R3, R5, R8, R10, R11, optical relays U3, U4, U5 and U6, wherein one end of each resistor R1, R3 and R5 is connected with an isolation amplifier U2 after being connected in parallel, one end of each resistor R8, R10 and R11 is connected with the isolation amplifier U2 after being connected in parallel, the optical relays U3 are connected between the R1 and R3, the optical relays U4 are connected between the R5 and the optical relays U3, the optical relays U5 are connected between the optical relays U6 and R8, and the optical relays U6 are connected between the R10 and the R11.
2. 2. A current sampling circuit for switching power by software according to claim 1 wherein said conversion unit comprises sampling resistors RA1, RA2, RA3, said resistors RA1, RA2, RA3 being connected in parallel.
3. 3. The current sampling circuit for switching power by software according to claim 1, further comprising an RC filter unit for RC filtering the voltage signal, wherein the RC filter unit comprises a resistor R7 and a capacitor C5, one end of the resistor R7 is connected to the conversion unit, the other end of the resistor R7 is connected to the isolation amplifier U2 through one end of the capacitor C5, and the capacitor C5 is connected in parallel with the conversion unit.
4. 4. The current sampling circuit for switching power by software according to claim 3, further comprising a voltage stabilizing and current limiting unit for stabilizing and limiting voltage signals, wherein the voltage stabilizing and current limiting unit comprises a current limiting resistor R4, a voltage stabilizing diode ZD1 and filter capacitors C1 and C2, one end of the current limiting resistor R4 is connected with the filter capacitors C1 and C2 which are sequentially connected in parallel through the voltage stabilizing diode ZD1, one end of the filter capacitor C2 is connected with an isolation amplifier U2, and the other end of the filter capacitor C2 is connected between the capacitor C5 and the isolation amplifier U2.
5. 5. The current sampling circuit for switching power by software of claim 1 wherein said isolation amplifier U2 is of the type NSI1300D25.
6. 6. The circuit for sampling power by software switching according to claim 1, wherein the optical relays U3, U4, U5, U6 are QX172-CuH-S.

Description

Current sampling circuit capable of switching power through software Technical Field The utility model relates to the technical field of frequency converters, in particular to a current sampling circuit capable of switching power through software. Background In most of the frequency converter designs nowadays, one power board is usually compatible with several kinds of power, and most of the power boards are compatible with different output powers of the frequency converter by changing the amplification factor of an amplifying circuit through a resistor short circuit or a dial mode to correspond to different current loops of software. However, the resistor short circuit or the dial-up mode is used for changing different power sections, so that the conditions of cold joint, wrong dial-up and the like are easy to occur, and the IGBT is not likely to be exploded due to the fact that the current loop corresponds. Disclosure of Invention The utility model aims to provide a current sampling circuit capable of switching power through software. In order to achieve the above purpose, the utility model provides a current sampling circuit for switching power by software, comprising: the conversion unit is used for acquiring current, converting the current into a voltage signal and uploading the voltage signal; the isolation amplifier U2 is used for amplifying the voltage signal and outputting the amplified voltage signal; The switching power unit is used for amplifying the amplified voltage signal after adjusting the amplification factor of the post-stage amplifying circuit; The switching power unit comprises resistors R1, R3, R5, R8, R10, R11, optical relays U3, U4, U5 and U6, wherein one end of each resistor R1, R3 and R5 is connected with an isolation amplifier U2 after being connected in parallel, one end of each resistor R8, R10 and R11 is connected with the isolation amplifier U2 after being connected in parallel, the optical relays U3 are connected between the R1 and R3, the optical relays U4 are connected between the R5 and the optical relays U3, the optical relays U5 are connected between the optical relays U6 and R8, and the optical relays U6 are connected between the R10 and the R11. Further, the conversion unit comprises sampling resistors RA1, RA2 and RA3, and the resistors RA1, RA2 and RA3 are connected in parallel. Further, the voltage signal filter circuit further comprises an RC filter unit for RC filtering the voltage signal, the RC filter unit comprises a resistor R7 and a capacitor C5, one end of the resistor R7 is connected with the conversion unit, the other end of the resistor R7 is connected with the isolation amplifier U2 through one end of the capacitor C5, and the capacitor C5 is connected with the conversion unit in parallel. Further, the voltage stabilizing and current limiting unit is used for stabilizing and limiting voltage signals and comprises a current limiting resistor R4, a voltage stabilizing diode ZD1 and filter capacitors C1 and C2, one end of the current limiting resistor R4 is connected with the filter capacitors C1 and C2 which are sequentially connected in parallel through the voltage stabilizing diode ZD1, one end of the filter capacitor C2 is connected with the isolation amplifier U2, and the other end of the filter capacitor C2 is connected between the capacitor C5 and the isolation amplifier U2. Further, the isolation amplifier U2 is of the type NSI1300D25. Further, the model numbers of the optical relays U3, U4, U5 and U6 are QX172-CuH-S. According to the technical scheme, the utility model has the following beneficial effects: The current sampling circuit with the power switched by the software sends a low-level signal to the optical relay through the DSP, after the optical relay is conducted, the amplification factor of a post-stage amplifying circuit of the current sampling circuit is changed, and the purpose of changing the power of the frequency converter is achieved corresponding to different current loops set by the software, so that the influence caused by misoperation can be reduced by setting the power of the frequency converter on a control panel. Drawings FIG. 1 is an overall circuit diagram of the present utility model; Fig. 2 is an overall circuit diagram of the optical relay of the present utility model. Detailed Description The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model. As shown in fig. 1-2, the utility model provides a current sampling circuit capable of switching power through software, which comprises a co