CN219779995U - TL 431-based multi-output voltage stabilizing control circuit - Google Patents

Abstract

The utility model provides a TL 431-based multi-output voltage stabilizing control circuit which comprises a transformation circuit, a multi-output circuit, an optocoupler isolation circuit, an overvoltage protection circuit and a PWM control module, wherein the input end of the transformation circuit is electrically connected with a switching power supply through a switching tube, and the output end of the transformation circuit is electrically connected with the multi-output circuit. The multi-path output circuit is provided with a plurality of voltage output ends, the overvoltage protection circuit is connected to each voltage output end and is used for detecting the overvoltage of the output voltage of each voltage output end and outputting a feedback signal through the optocoupler isolation circuit, and the PWM control module is connected to the feedback signal and inputs PWM signals to the voltage transformation circuit.

Description

TL 431-based multi-output voltage stabilizing control circuit

Technical Field

The utility model relates to the technical field of output protection, in particular to a TL 431-based multi-output voltage stabilizing control circuit.

Background

The voltage stabilizing circuit is a circuit which can still keep the output voltage constant when the input voltage, load, ambient temperature, circuit parameters and the like change, can provide a stable direct current power supply, is widely used in various electronic equipment at present, can provide power for module circuits such as chips and the like in the equipment, has a complex structure, large fluctuation range of the output voltage, high electronic cost and various electronic components, and is not easy to overhaul and maintain.

Disclosure of Invention

The present utility model is directed to a TL 431-based multi-output voltage stabilizing control circuit, so as to solve the above-mentioned problems in the prior art.

The utility model is realized by the following technical scheme: the utility model provides a stable voltage control circuit based on TL431 multiple output, includes voltage transformation circuit, multiple output circuit, opto-coupler isolation circuit, overvoltage protection circuit, PWM control module, voltage transformation circuit's input links to each other with switching power supply electricity, its output with multiple output circuit electricity links to each other. The multi-path output circuit is provided with a plurality of voltage output ends, the overvoltage protection circuit is connected to each voltage output end and is used for detecting the overvoltage of the output voltage of each voltage output end and outputting a feedback signal through the optocoupler isolation circuit, and the PWM control module is connected to the feedback signal and inputs PWM signals to the voltage transformation circuit.

Optionally, the transformer circuit includes a transformer formed by a primary coil and a plurality of secondary coils, the input end of the primary coil is electrically connected with the switching power supply, the primary coil is coupled with the plurality of secondary coils, and the secondary coils are electrically connected with the multi-output circuit.

Optionally, the multi-path output circuit has three paths of outputs, and each path of output is composed of a rectifier diode and a filter capacitor.

Optionally, each voltage output end of the multiplexing output circuit is electrically connected with the overvoltage protection circuit through a voltage dividing circuit.

Optionally, the overvoltage protection circuit is an integrated circuit with a TL431 chip.

Optionally, the PWM control module is a PWM controller.

Compared with the prior art, the utility model has the following beneficial effects:

the voltage stabilizing control circuit based on TL431 multi-output provided by the utility model has the advantages that the voltage of different sizes is outputted by the voltage transforming circuit through reducing voltage of different turn ratios, the rectifying and filtering of the multi-output voltage is realized by the multi-output circuit, when a load fluctuates, the voltage stabilizing circuit formed by single TL431 is used for guaranteeing the stability of the output voltage by adjusting the voltage through the current flowing through the circuit, meanwhile, the voltage stabilizing control circuit is also used for comparing whether the multi-output voltage exceeds a set range, and different levels are outputted to the optocoupler isolation circuit after the comparison, so that the current voltage of the optocoupler isolation circuit for the FB pin of the PWM control module is changed, the PWM wave output of the PWM control module is regulated, and finally, the voltage stabilizing protection of the circuit is realized by adopting a single TL431 element as a voltage stabilizing datum point.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings required for the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only preferred embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a voltage stabilizing control circuit based on TL431 multiplexing output;

FIG. 2 is a schematic diagram of a transformer circuit and a multiplexing circuit according to the present utility model;

fig. 3 is a schematic circuit diagram of an overvoltage protection circuit and an optocoupler isolation circuit provided by the utility model.

In the figure, a switching power supply 101, a transformer circuit 102, a multiplexing output circuit 103, a voltage output end 104, an overvoltage protection circuit 105, an optocoupler isolation circuit 106 and a PWM control module 107.

Detailed Description

In order to make the objects, technical solutions and advantages of the present utility model more apparent, exemplary embodiments according to the present utility model will be described in detail with reference to the accompanying drawings. It should be apparent that the described embodiments are only some embodiments of the present utility model and not all embodiments of the present utility model, and it should be understood that the present utility model is not limited by the example embodiments described herein. Based on the embodiments of the utility model described in the present application, all other embodiments that a person skilled in the art would have without inventive effort shall fall within the scope of the utility model.

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present utility model. It will be apparent, however, to one skilled in the art that the utility model may be practiced without one or more of these details. In other instances, well-known features have not been described in detail in order to avoid obscuring the utility model.

It should be understood that the present utility model may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the utility model to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

In order to provide a thorough understanding of the present utility model, detailed structures will be presented in the following description in order to illustrate the technical solutions presented by the present utility model. Alternative embodiments of the utility model are described in detail below, however, the utility model may have other implementations in addition to these detailed descriptions.

Referring to fig. 1, a TL 431-based multi-output voltage stabilizing control circuit includes a transformer circuit 102, a multi-output circuit 103, an optocoupler isolation circuit 106, an overvoltage protection circuit 105, and a PWM control module 107, where an input end of the transformer circuit 102 is electrically connected to a switching power supply 101, and an output end of the transformer circuit is electrically connected to the multi-output circuit 103. The multi-output circuit 103 has a plurality of voltage output terminals 104, the overvoltage protection circuit 105 is connected to each voltage output terminal 104, and is configured to perform overvoltage detection on an output voltage of each voltage output terminal 104, and output a feedback signal through the optocoupler isolation circuit 106, and the PWM control module 107 is connected to the feedback signal, and inputs a PWM signal to the voltage transformation circuit 102.

The utility model discloses a voltage stabilizing control circuit based on TL431 multiplexing output, which is characterized in that a voltage transformation circuit 102 outputs voltages with different magnitudes through voltage reduction of different turn ratios, rectification filtering of the multiplexing output voltage is realized through a multiplexing output circuit 103, when a load fluctuates, an overvoltage protection circuit 105 adjusts the voltage through current flowing through the voltage transformation circuit to ensure the stability of the output voltage, meanwhile, the voltage transformation circuit is also used for comparing whether the multiplexing output voltage exceeds a set range or not, and outputting different levels to an optocoupler isolation circuit 106 after comparison, so that the current voltage of an FB pin of the optocoupler isolation circuit 106 is caused to change, and further PWM wave output of a PWM control module 107 is regulated, and the voltage transformation circuit 102 realizes regulation according to PWM waves, and finally realizes voltage stabilizing protection of the circuit.

Specifically, the transformer circuit 102 includes a transformer composed of a primary coil and a plurality of secondary coils, one end of the primary coil is electrically connected to the switching power supply 101, the other end is electrically connected to the PWM control module 107 through the switching tube Q2, the primary coil is coupled to the plurality of secondary coils, and the secondary coils are electrically connected to the multiplexing circuit 103, and in this embodiment, voltages of 5v,12v and 18v are output through different turn ratios of the plurality of secondary coils.

As shown in fig. 2, specifically, the multiple output circuit 103 has three outputs, each of which is formed by a rectifying diode and a filter capacitor, where D1 is a 5V output rectifying diode, C1, C2, C3 is a 5V output filter capacitor, D2 is a 12V output rectifying diode, C4, C5, C6 is a 12V output filter capacitor, D3 is an 18V output rectifying diode, C7, C8, C9 is an 18V output filter capacitor, and U1 adjusts PWM through feedback of the multiple output voltage stabilizing control circuit, so that the output can be controlled.

As shown in fig. 3, each voltage output terminal 104 of the multiplexing circuit 103 is electrically connected to the overvoltage protection circuit 105 through a voltage dividing circuit, wherein the 5V output is stabilized by the voltage division between R7 and R13. 12V is stabilized by the partial pressures of R8 and R13, and 18V is stabilized by the partial pressures of R9 and R13.

As shown in fig. 3, the optocoupler isolation circuit 106 includes an optocoupler, and the optocoupler is connected to the FB pin of the PWM control module 107, where R2, R3, and R4 are optocoupler power supply pins, and 5v,12v, and 18v may be selected to supply power to the optocoupler. R6 acts to shunt the optocoupler. R11, C10 function as RC loop modulation.

As shown in fig. 3, the overvoltage protection circuit 105 is an integrated circuit with a TL431 chip, the TL431 reference voltage is 2.5V, the lower voltage dividing resistor R13 is fixed, if 4 output paths and 5 output paths need to be added, the lower voltage dividing resistor R13 is fixed, and the voltage dividing resistor resistance value can be adjusted to realize multi-path voltage stabilizing output by continuously adding the upper voltage dividing resistor.

In this embodiment, when the load connected to the multiple output circuit 103 fluctuates, the TL431 chip adjusts the voltage by flowing its own current, so as to ensure the stability of the output voltage, and when the output voltage of the multiple output circuit 103 is over-voltage, the VREF pin of the TL431 chip itself is raised, and its internal comparator will be compared with the VREF reference voltage, so that the op amp inside the TL431 chip outputs a high level, and finally the cathode output voltage of the TL431 chip is reduced, which will cause the increase of the current flowing into the optocoupler isolation circuit 106, that is, the voltage of the FB pin sent to the PWM control module 107 increases, and the FB pin will continue to be compared with the internal reference voltage, so as to adjust the PWM output, and then adjust the closing condition of the switching tube Q2, so as to finally realize the output adjustment of the voltage transformation circuit 102.

Specifically, the PWM control module 107 is a PWM controller.

It should be noted that, the circuits and electronic elements such as the switching power supply 101, the optocoupler and the like used in the present utility model are all products in the prior art, and those skilled in the art select, install and complete the debugging operation of the circuits according to the use requirement, so as to ensure that each electrical appliance can work normally, and the components are all universal standard components or components known to those skilled in the art, and the structures and principles of the components are all known to those skilled in the art through technical manuals or known through conventional experimental methods, so that the present utility model is not limited in this way.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather to enable any modification, equivalent replacement, improvement or the like to be made within the spirit and principles of the utility model.

Claims (6)

1. The utility model provides a stable voltage control circuit based on TL431 multiple output, its characterized in that includes voltage transformation circuit, multiple output circuit, opto-coupler isolation circuit, overvoltage protection circuit, PWM control module, voltage transformation circuit's input passes through the switching tube and links to each other with switching power supply electricity, its output with multiple output circuit electricity links to each other, multiple output circuit has a plurality of voltage output ends, overvoltage protection circuit inserts every voltage output end for carry out overvoltage detection to the output voltage of every voltage output end, and output feedback signal through opto-coupler isolation circuit, PWM control module inserts feedback signal, and to voltage transformation circuit input PWM signal.

2. The TL431 based multiple output voltage stabilizing control circuit of claim 1, wherein said voltage transforming circuit comprises a transformer comprising a primary winding and a plurality of secondary windings, wherein an input of said primary winding is electrically connected to a switching power supply, said primary winding is coupled to said plurality of secondary windings, and said secondary windings are electrically connected to said multiple output circuit.

3. The TL431 based multiple output voltage regulator control circuit of claim 1, wherein said multiple output circuit has three outputs, each of which is comprised of a rectifier diode and a filter capacitor.

4. The TL431 based multiple output voltage regulator control circuit of claim 1, wherein each voltage output of said multiple output circuit is electrically connected to said overvoltage protection circuit by a voltage divider circuit.

5. The TL431 based multiple output voltage regulator control circuit of claim 4, wherein said overvoltage protection circuit is an integrated circuit with a TL431 chip.

6. The TL431 based multiple output voltage regulator control circuit of claim 1, wherein said PWM control module is a PWM controller.