CN210490744U

CN210490744U - High-precision multi-output constant-voltage source

Info

Publication number: CN210490744U
Application number: CN201920880227.8U
Authority: CN
Inventors: 杨婷
Original assignee: Shaoxing University Yuanpei College
Current assignee: Shaoxing University Yuanpei College
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2020-05-08
Anticipated expiration: 2029-06-12

Abstract

The utility model discloses a high accuracy multichannel output constant voltage source, including input module, transformer, multichannel output module and control module, still include feedback circuit, feedback circuit connects multichannel output module and control module, and feedback circuit includes opto-coupler U4, controllable steady voltage source U7, electric capacity C12 and a plurality of resistance, controllable steady voltage source U7's reference pole passes through resistance R5 and connects multichannel output module and through resistance R6 ground connection, and controllable steady voltage source U7's negative pole is connected opto-coupler U4 input and is connected first output through resistance R7, controllable steady voltage source U7's positive pole ground connection, and multichannel output module is connected to resistance R8 one end, and electric capacity C12 one end is connected to the resistance R8 other end, and controllable steady voltage source U7 reference pole is connected to the electric capacity C12 other end, and opto-coupler U4 output connection control module. The utility model discloses beneficial effect includes: the interference among the modules is small, the power supply operation stability is high, the reliability is high, the structure is simple, and the cost is low.

Description

High-precision multi-output constant-voltage source

Technical Field

The utility model relates to a power technical field, in particular to high accuracy multiplexed output constant voltage source.

Background

The power supply is the heart part of the electronic equipment, and the quality of the power supply directly influences the reliability of the electronic equipment. The power supplies used by modern electronic devices are roughly divided into two categories, namely linear voltage-stabilized power supplies and switching power supplies, and the linear power supplies have low efficiency while the switching power supplies have high efficiency. The advantages of the device are mainly represented by the aspects of small power consumption, wide voltage stabilizing range, small volume, light weight, safety, reliability and the like. Research on switching power supply related technologies is in a rapidly growing stage, particularly for multiplexed output power supplies.

The invention application of the publication number CN105978343A discloses a multi-output switch power supply and an inverter, wherein an auxiliary voltage output end of the multi-output switch power supply is connected with a protection circuit in parallel; the protection circuit comprises a switching device and a resistor, and the switching device is connected with the resistor in series; the multi-output switch power supply also comprises a control circuit; the control circuit is used for controlling the switching device to be closed before an auxiliary output load of the multi-output switching power supply is connected into the circuit.

The control circuit in the prior art may affect the primary end of the transformer, resulting in uncontrollable variation of voltage or current, and reduced power stability, while some prior art only control the power output end to prevent the above problem, but may cause weaker control capability, and is also not favorable for power stability.

SUMMERY OF THE UTILITY MODEL

To prior art to the primary end production influence of transformer, the relatively poor problem of power stability, the utility model provides a high accuracy multiplexed output constant voltage source through feedback circuit connection output and control circuit, realizes reducing the unnecessary influence of input and output, makes control circuit stability improve to improve the stability of whole power.

The technical scheme of the utility model is as follows.

A high-precision multi-output constant-voltage source comprises an input module, a transformer, a multi-output module, a control module and a feedback circuit, wherein the feedback circuit is connected with the multi-output module and the control module and comprises an optical coupler U4, a controllable voltage-stabilizing source U7, a capacitor C12 and a plurality of resistors, a reference electrode of the controllable voltage-stabilizing source U7 is connected with the multi-output module through a resistor R5 and is grounded through a resistor R6, a cathode of the controllable voltage-stabilizing source U7 is connected with an input end of an optical coupler U4 and is connected with a first output end through a resistor R7, an anode of the controllable voltage-stabilizing source U7 is grounded, one end of a resistor R8 is connected with the multi-output module, the other end of the resistor R8 is connected with one end of the capacitor C12, the other end of the capacitor C12 is connected with a reference electrode. Direct circuit connection does not exist between the output module and the control module through the optical coupler U7, namely interference of the output module to the control module is reduced to the greatest extent, only the relation of necessary control signals between the two modules is reserved, and the overall stability is improved.

Preferably, the type of the optical coupler U4 is PC 816. The model has mature technology and higher reliability and stability, and is suitable for being used in a power supply.

Preferably, the controllable voltage regulator source U7 is model number TL 431. TL431 is a controllable precision voltage regulator. Its output voltage can be arbitrarily set to any value ranging from Vref (2.5V) to 36V with two resistors. The device is used in many applications to replace a zener diode. The method is widely applied to the fields of switching power supplies and the like.

Preferably, the multi-output module includes three sub-output terminals, and the feedback circuit is connected to any one of the sub-output terminals. If each output terminal is connected with a set of feedback circuit and control module, the stability is poor and the cost is high, so that one output terminal can be used.

Preferably, the control module comprises a control chip U5, a plurality of capacitors, a plurality of resistors and a MOS tube Q1, wherein an output compensation pin of the control chip U5 is connected with the feedback circuit, a voltage feedback pin of the control chip U5 is grounded, a current sampling pin of the control chip U5 is grounded through a capacitor C13, an RT/CT pin of the control chip U5 is grounded through a capacitor C14, an output pin of the control chip U5 is connected with a grid electrode of the MOS tube Q1, a REF pin of the control chip U5 is connected with the RT/CT pin through a resistor R10, a drain electrode of the MOS tube Q1 is connected with the input module, and a source electrode of the MOS tube Q1 is grounded through a resistor R9. The control chip U5 processes the signals transmitted by the feedback circuit and controls the MOS tube Q1 to realize the control of the input module.

Preferably, the model of the control chip U5 is UC 3843. UC3843 is a high performance fixed frequency current mode controller, specifically designed for off-line and dc-dc converter applications, providing designers with a cost-effective solution requiring minimal external components. These integrated circuits have a trimmable oscillator, a reference that enables precise duty cycle control, temperature compensation, a high gain error amplifier, a current sampling comparator, and a high current totem-pole output, and are ideal devices for driving power MOSFETs.

Preferably, the MOS transistor Q1 is of the type IRF 150. The model has mature technology and higher reliability and stability.

The utility model discloses beneficial effect includes: the interference among the modules is small, the power supply operation stability is high, the reliability is high, the structure is simple, and the cost is low.

Drawings

Fig. 1 is an overall schematic diagram of an embodiment of the present invention;

fig. 2 is a schematic diagram of a feedback circuit according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of a control module according to an embodiment of the present invention;

in the figure: the circuit comprises an input module 1, a transformer 2, a multi-path output module 3, a control module 4 and a feedback circuit 5.

Detailed Description

The technical scheme is further explained by combining the drawings in the specification.

Example (b):

as shown in fig. 1, a high-precision multi-output constant voltage source includes an input module 1, a transformer 2, a multi-output module 3, a control module 4 and a feedback circuit 5, wherein the input module 1 is an ac input of 220V and 50Hz and is connected to a primary end of the transformer 5 after rectification and filtering, a secondary end of the transformer 5 is divided into multiple sections and connected to the multi-output module 3, the feedback circuit 5 is used as a transition module for connecting the multi-output module 3 and the control module 4, and finally the control module 4 controls the input of the input module 1 to the transformer 2.

The multi-output module 3 of the present embodiment includes 3 sub-output terminals, and the feedback circuit 5 is connected to one of the sub-output terminals.

Fig. 2 shows a specific circuit schematic diagram of the feedback circuit 5 of this embodiment, which includes an optocoupler U4, a controllable regulator U7, a capacitor C12, and a plurality of resistors, wherein a reference electrode of the controllable regulator U7 is connected to the multi-output module through a resistor R5 and grounded through a resistor R6, a cathode of the controllable regulator U7 is connected to an input end of the optocoupler U4 and connected to a first output end through a resistor R7, an anode of the controllable regulator U7 is grounded, one end of the resistor R8 is connected to the multi-output module, the other end of the resistor R8 is connected to one end of the capacitor C12, the other end of the capacitor C12 is connected to the reference electrode of the controllable regulator U7, and an output end of the optocoupler U4. Direct circuit connection does not exist between the output module and the control module through the optical coupler U7, namely interference of the output module to the control module is reduced to the greatest extent, only the relation of necessary control signals between the two modules is reserved, and the overall stability is improved.

The type of the optical coupler U4 is PC 816. The model has mature technology and higher reliability and stability, and is suitable for being used in a power supply. Controllable regulator U7 is model number TL 431. TL431 is a controllable precision voltage regulator. Its output voltage can be arbitrarily set to any value ranging from Vref (2.5V) to 36V with two resistors. The device is used in many applications to replace a zener diode. The method is widely applied to the fields of switching power supplies and the like.

As shown in fig. 3, the control module 4 of the present embodiment is a schematic circuit diagram, the control module 4 includes a control chip U5, a plurality of capacitors, a plurality of resistors, and a MOS transistor Q1, an output compensation pin of the control chip U5 is connected to a feedback circuit, a voltage feedback pin of the control chip U5 is grounded, a current sampling pin of the control chip U5 is grounded through a capacitor C13, an RT/CT pin of the control chip U5 is grounded through a capacitor C14, an output pin of the control chip U5 is connected to a gate of the MOS transistor Q1, a REF pin of the control chip U5 is connected to the RT/CT pin through a resistor R10, a drain of the MOS transistor Q1 is connected to an input module, and a source of the MOS transistor Q1 is grounded through a resistor R9. The control chip U5 processes the signals transmitted by the feedback circuit and controls the MOS tube Q1 to realize the control of the input module.

The model of the MOS transistor Q1 is IRF150, and the model of the control chip U5 is UC 3843. UC3843 is a high performance fixed frequency current mode controller, specifically designed for off-line and dc-dc converter applications, providing designers with a cost-effective solution requiring minimal external components. These integrated circuits have a trimmable oscillator, a reference that enables precise duty cycle control, temperature compensation, a high gain error amplifier, a current sampling comparator, and a high current totem-pole output, and are ideal devices for driving power MOSFETs.

It should be noted that the specific embodiment is only used for further illustration of the technical solution, and is not used for limiting the scope of the technical solution, and any modification, equivalent replacement, improvement and the like based on the technical solution should be considered as being within the protection scope of the present invention.

Claims

1. A high-precision multi-output constant-voltage source comprises an input module, a transformer, a multi-output module and a control module, and is characterized by further comprising a feedback circuit, wherein the feedback circuit is connected with the multi-output module and the control module, the feedback circuit comprises an optocoupler U4, a controllable voltage-stabilizing source U7, a capacitor C12 and a plurality of resistors, a reference electrode of the controllable voltage-stabilizing source U7 is connected with the multi-output module through a resistor R5 and is grounded through a resistor R6, a cathode of the controllable voltage-stabilizing source U7 is connected with an input end of an optocoupler U4 and is connected with a first output end through a resistor R7, an anode of the controllable voltage-stabilizing source U7 is grounded, one end of a resistor R8 is connected with the multi-output module, the other end of the resistor R8 is connected with one end of the capacitor C12, the other end of the capacitor C12 is connected.

2. A high precision multiple output constant voltage source according to claim 1, wherein said optical coupler U4 is PC 816.

3. A high precision multiple output constant voltage source as claimed in claim 1 wherein the controllable regulator U7 is model number TL 431.

4. A high precision multiple output constant voltage source as claimed in claim 1, wherein said multiple output module comprises three sub-outputs, and said feedback circuit is connected to any one of said sub-outputs.

5. The high-precision multi-output constant-voltage power supply as claimed in claim 1 or 4, wherein the control module comprises a control chip U5, a plurality of capacitors, a plurality of resistors and a MOS tube Q1, the output compensation pin of the control chip U5 is connected with the feedback circuit, the voltage feedback pin of the control chip U5 is grounded, the current sampling pin of the control chip U5 is grounded through a capacitor C13, the RT/CT pin of the control chip U5 is grounded through a capacitor C14, the output pin of the control chip U5 is connected with the gate of the MOS tube Q1, the REF pin of the control chip U5 is connected with the RT/CT pin through a resistor R10, the drain of the MOS tube Q1 is connected with the input module, and the source of the MOS tube Q1 is grounded through a resistor R9.

6. A high precision multiple output constant voltage source as claimed in claim 5, wherein said control chip U5 is model UC 3843.

7. A high precision multiple output constant voltage source as claimed in claim 5, wherein said MOS transistor Q1 is type IRF 150.