CN215180474U

CN215180474U - Non-isolated terminal voltage monitoring circuit of isolated power supply

Info

Publication number: CN215180474U
Application number: CN202120836907.7U
Authority: CN
Inventors: 周国华
Original assignee: Zhongshan Junchuang Electronic Technology Co ltd
Current assignee: Zhongshan Junchuang Electronic Technology Co ltd
Priority date: 2021-04-22
Filing date: 2021-04-22
Publication date: 2021-12-14
Anticipated expiration: 2031-04-22

Abstract

The utility model relates to an keep apart non-isolation terminal voltage monitoring circuit of power, including the transformer, the primary winding of transformer connects the interchange source, the secondary winding connection load of transformer, its characterized in that: the input side of the isolation power supply is provided with a first single chip microcomputer and an electric sampling circuit, and the output side of the isolation power supply is provided with a second single chip microcomputer; the sampling pin of the first single chip microcomputer is connected with an electric sampling circuit to obtain the electric signal change of an input side, and the electric sampling circuit is arranged on or connected to a primary winding of the transformer; the second single chip microcomputer is connected with the first single chip microcomputer through an isolation circuit and used for receiving the electric signals acquired by the first single chip microcomputer so as to control the output side of the isolation circuit. This application utilizes and locates the first singlechip of non-isolation end to carry out the electricity sampling, and transmission signal to the second singlechip of keeping apart the end is kept apart to the digital opto-coupler isolation module of rethread, has avoided second singlechip lug connection non-isolation end to carry out the risk of sampling, the electrical isolation degree of guarantee circuit.

Description

Non-isolated terminal voltage monitoring circuit of isolated power supply

Technical Field

The utility model relates to an keep apart non-isolation terminal voltage monitoring circuit of power.

Background

The isolation power supply is provided with a transformer for isolating an alternating current input part and a direct current output part, and the direct current output part is provided with a singlechip for realizing output control. In order to respond to the electric signal change of the non-isolated end (i.e. input side) of the isolated power supply to adjust and control the output state, for example, to cut off the dc output when the voltage or current of the non-isolated end is too high, the single chip microcomputer in the dc output part needs to obtain the electric signal change of the non-isolated end of the isolated power supply in real time, that is, needs to be connected with the non-isolated end of the isolated power supply through the sampling circuit. Because the working voltage difference between the alternating current input part and the direct current output part is large, if the single chip microcomputer is connected with a non-isolation end through a simple sampling circuit, high risk exists, and therefore isolation design is needed.

SUMMERY OF THE UTILITY MODEL

Based on the background art, the utility model discloses an isolation power supply non-isolation terminal voltage monitoring circuit, it realizes through following technological means: the non-isolated terminal voltage monitoring circuit of the isolated power supply comprises a transformer, a primary winding of the transformer is connected with an alternating current source, a secondary winding of the transformer is connected with a load, a first single chip microcomputer and an electric sampling circuit are arranged on the input side of the isolated power supply, and a second single chip microcomputer is arranged on the output side of the isolated power supply; the sampling pin of the first single chip microcomputer is connected with an electric sampling circuit to obtain the electric signal change of an input side, and the electric sampling circuit is arranged on or connected to a primary winding of the transformer; the second single chip microcomputer is connected with the first single chip microcomputer through an isolation circuit and used for receiving the electric signals acquired by the first single chip microcomputer so as to control the output side of the isolation circuit.

In the middle of one or more embodiments of the utility model, isolating circuit includes digital opto-coupler isolation module, digital opto-coupler isolation module's input is connected with the signal output foot of first singlechip, and its output is connected with the signal input foot of second singlechip.

In one or more embodiments of the present invention, the electrical sampling circuit includes a diode D1, resistors R1 and R2, and a capacitor C1, the anode of the diode D1 is connected to the primary winding of the transformer, the cathode of the diode D1 is connected to the ground through resistors R1 and R2 in series, the connection point of the resistors R1 and R2 is used as the output terminal of the electrical sampling circuit and is connected to the sampling pin of the first single chip, and the capacitor C1 is connected to both ends of the resistor R2.

In one or more embodiments of the present invention, the VCC pin and the VSS pin of the first single chip are connected to the feedback winding of the transformer.

The utility model has the advantages that: the first singlechip of locating the non-isolation end of buffer circuit carries out voltage sampling, and the second singlechip of transmission signal to isolation end is kept apart to rethread digital opto-coupler isolation module, has avoided second singlechip lug connection non-isolation end to carry out the risk of sampling, the electrical isolation of guarantee circuit. And the first single chip microcomputer is used for isolating and transferring the sampling signal, so that the matching problem of the sampling voltage and the output signal is well solved, the circuit structure of the electric sampling circuit can be simplified, the output signal of the first single chip microcomputer can meet the input requirement of the digital optical coupling isolation module, the complicated sampling circuit design is not needed, and the whole implementation cost is low. In addition, the selection of the first single chip microcomputer can be to newly set a single chip microcomputer chip or directly use a switch chip of a non-isolated end, preferably the switch chip of the non-isolated end, can further reduce the cost and does not need to greatly change an original isolated power supply circuit, has better technical performance, economical efficiency and practicability, and is suitable for popularization and application.

Drawings

Fig. 1 is a schematic diagram of the circuit framework of the present invention.

Fig. 2 is a schematic diagram of the electrical sampling circuit of the present invention.

Detailed Description

The application is further described below with reference to the accompanying drawings:

referring to the attached figure 1, the non-isolated terminal voltage monitoring circuit of the isolated power supply comprises a transformer, a primary winding of the transformer is connected with an alternating current source, a secondary winding of the transformer is connected with a load, a first single chip microcomputer and an electric sampling circuit are arranged on the input side of the isolated power supply, and a second single chip microcomputer is arranged on the output side of the isolated power supply; the sampling pin of the first single chip microcomputer is connected with an electric sampling circuit to obtain the electric signal change of an input side, and the electric sampling circuit is arranged on or connected to a primary winding of the transformer; the second single chip microcomputer is connected with the first single chip microcomputer through an isolation circuit and used for receiving the electric signals acquired by the first single chip microcomputer so as to control the output side of the isolation circuit.

Specifically, the isolation circuit comprises a digital optical coupling isolation module, wherein the input end of the digital optical coupling isolation module is connected with the signal output pin of the first single chip microcomputer, and the output end of the digital optical coupling isolation module is connected with the signal input pin of the second single chip microcomputer. Referring to fig. 2, the electrical sampling circuit comprises a diode D1, resistors R1 and R2, and a capacitor C1, wherein the anode of the diode D1 is connected to the primary winding of the transformer, the cathode of the diode D1 is connected to the ground in series through resistors R1 and R2, the connection point of the resistors R1 and R2 is used as the output end of the electrical sampling circuit and is connected to the sampling pin AD of the first singlechip, and the capacitor C1 is connected to the two ends of the resistor R2 in parallel.

In the above embodiment, the first single chip microcomputer arranged at the non-isolation end of the isolation circuit is used for electrical sampling, and the digital optical coupling isolation module is used for isolating the transmission signal to the second single chip microcomputer at the isolation end, so that the risk that the second single chip microcomputer is directly connected with the non-isolation end for sampling is avoided, and the electrical isolation degree of the circuit is guaranteed. And the first single chip microcomputer is used for isolating and transferring the sampling signal, so that the matching problem of the sampling voltage and the output signal is well solved, the circuit structure of the electric sampling circuit can be simplified, the output signal of the first single chip microcomputer can meet the input requirement of the digital optical coupling isolation module, the complicated sampling circuit design is not needed, and the whole implementation cost is low.

In addition, the first single chip microcomputer can be selected by newly arranging a single chip microcomputer chip or directly using a switch chip of a non-isolation end, the cost of the first single chip microcomputer is not greatly increased, and the cost of the second single chip microcomputer can be further reduced without greatly changing the original isolation power supply circuit.

The above preferred embodiments should be considered as examples of the embodiments of the present application, and technical deductions, substitutions, improvements and the like similar to, similar to or based on the embodiments of the present application should be considered as the protection scope of the present patent.

Claims

1. A non-isolated terminal voltage monitoring circuit of an isolated power supply comprises a transformer, wherein a primary winding of the transformer is connected with an alternating current source, and a secondary winding of the transformer is connected with a load, and is characterized in that: the input side of the isolation power supply is provided with a first single chip microcomputer and an electric sampling circuit, and the output side of the isolation power supply is provided with a second single chip microcomputer; the sampling pin of the first single chip microcomputer is connected with an electric sampling circuit to obtain the electric signal change of an input side, and the electric sampling circuit is arranged on or connected to a primary winding of the transformer; the second single chip microcomputer is connected with the first single chip microcomputer through an isolation circuit and used for receiving the electric signals acquired by the first single chip microcomputer so as to control the output side of the isolation circuit.

2. The isolated power supply non-isolated terminal voltage monitoring circuit of claim 1, wherein: the isolation circuit comprises a digital optical coupling isolation module, wherein the input end of the digital optical coupling isolation module is connected with the signal output pin of the first single chip microcomputer, and the output end of the digital optical coupling isolation module is connected with the signal input pin of the second single chip microcomputer.

3. The isolated power supply non-isolated terminal voltage monitoring circuit of claim 1, wherein: the electric sampling circuit comprises a diode D1, resistors R1 and R2 and a capacitor C1, wherein the anode of the diode D1 is connected with the primary winding of the transformer, the cathode of the diode D1 is connected with the ground in series through the resistors R1 and R2, the connection point of the resistors R1 and R2 is used as the output end of the electric sampling circuit and is connected with the sampling pin of the first singlechip, and the capacitor C1 is connected to the two ends of the resistor R2 in parallel.

4. The isolated power supply non-isolated terminal voltage monitoring circuit of claim 1, wherein: and a VCC pin and a VSS pin of the first singlechip are connected to a feedback winding of the transformer.