Switching power supply circuit with wide voltage input and output

Abstract

The utility model discloses a switching power supply circuit with wide voltage input and output, which is characterized in that an AC input voltage doubling rectification filter circuit, an input and output voltage isolation conversion circuit and an output rectification circuit which are connected in sequence are arranged between a circuit input end and a circuit output end; the LED driving circuit comprises an input and output voltage isolation conversion circuit, a VCC power supply circuit, a high voltage output constant power compensation circuit, a PWM control circuit, a low voltage output constant power compensation circuit, an LED driving and output voltage control circuit and a step-down circuit, the input and output voltage isolation conversion circuit is connected with the VCC power supply circuit, and the VCC power supply circuit is connected with the high voltage output constant power compensation circuit and the PWM control circuit. The high-voltage output constant-power compensation circuit is connected with the PWM control circuit, the PWM control circuit is connected with the circuit output end through the low-voltage output constant-power compensation circuit, the LED driving and output voltage control circuit and the step-down circuit, the universality is good, and the compatibility is strong.

Description

Technical Field

[0001] The utility model relates to the technical field of switching power supplies, in particular to a switching power supply circuit with wide voltage input and output. Background Art

[0002] With the development of society, the demand for lighting applications is pursuing personalization and diversification of lighting application scenarios, and there are more and more demands for different specifications of power supplies and different specifications of loads. However, different specifications of power supplies and different specifications of loads, especially LED adaptation, have poor versatility. It is necessary to equip power adapters of the same specifications to drive matching LED loads, which has great limitations in application, and sometimes it is necessary to add a voltage divider circuit, which is too cumbersome, inefficient, and has poor compatibility.

[0003] Therefore, it is necessary to improve the existing switching power supply circuit. Utility Model Content

[0004] The utility model aims to solve one of the problems existing in the existing related technologies to at least a certain extent. To this end, one purpose of the utility model is to provide a switching power supply circuit with wide voltage input and output, which has good versatility and strong compatibility.

[0005] The above purpose is achieved through the following technical solutions:

[0006] A switching power supply circuit with wide voltage input and output comprises a circuit input end and a circuit output end, wherein an AC input voltage doubling rectifier filter circuit, an input-output voltage isolation conversion circuit and an output rectifier circuit connected in sequence are arranged between the circuit input end and the circuit output end, and further comprises a VCC power supply circuit, a high voltage output constant power compensation circuit, a PWM control circuit, a low voltage output constant power compensation circuit, an LED drive and output voltage control circuit and a step-down circuit, wherein the input-output voltage isolation conversion circuit is connected to the VCC power supply circuit, the VCC power supply circuit is respectively connected to the high voltage output constant power compensation circuit and the PWM control circuit, and the high voltage output constant power compensation circuit introduces the VCC voltage into the PWM control circuit through a sampling circuit, the PWM control circuit is connected to the low voltage output constant power compensation circuit to introduce the FB voltage of the PWM control circuit into the ground line through the sampling circuit, and the low voltage output constant power compensation circuit is connected to the circuit output end through the LED drive and output voltage control circuit and the step-down circuit, and the step-down circuit adopts a dissipative MOS and an LDO linear step-down chip to form a double-stage step-down power supply circuit to power a display screen module.

[0007] In some implementations, a power driving circuit is provided between the input-output voltage isolation conversion circuit and the PWM control circuit.

[0008] In some implementations, a photoelectric isolation feedback circuit is provided between the low voltage output constant power compensation circuit and the LED driving and output voltage control circuit.

[0009] In some implementations, an LED display circuit is further included, which is connected to the LED driving and output voltage control circuit.

[0010] In some implementations, an output voltage sampling circuit is further included, which is connected between the LED driving and output voltage control circuit and the circuit output terminal.

[0011] In some embodiments, it also includes a display screen module driven by the MCU and a touch-type selection key, and a combination of the display screen module driven by the MCU and the touch-type selection key is used to select different output voltages and voltage displays;

[0012] Or it includes a plurality of sets of mechanical pull switches, which are connected to the reference source chip through the downward bias resistors connected in series on the plurality of sets of mechanical pull switches, and different output voltages are selected through the plurality of sets of mechanical pull switches.

[0013] Compared with the prior art, the present invention has at least the following beneficial effects:

[0014] 1. The utility model provides a switching power supply circuit with wide voltage input and output, which has good versatility and strong compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a circuit block diagram of a switching power supply circuit in an embodiment;

[0016] Figure 2 Schematic diagram of a switching power supply circuit in an embodiment. DETAILED DESCRIPTION

[0017] The following examples illustrate the present invention, but the present invention is not limited by these examples. Modifications to the specific implementation of the present invention or equivalent replacement of some technical features without departing from the spirit of the present invention should be included in the scope of the technical solution claimed for protection in the present invention.

[0018] Embodiment 1: Figure 1 and Figure 2As shown, this embodiment provides a switching power supply circuit with wide voltage input and output, including a circuit input end and a circuit output end, between which an AC input voltage doubling rectifier filter circuit, an input-output voltage isolation conversion circuit and an output rectifier circuit connected in sequence are arranged, and also includes a VCC power supply circuit, a high voltage output constant power compensation circuit, a PWM control circuit, a low voltage output constant power compensation circuit, an LED drive and output voltage control circuit and a step-down circuit, wherein the input-output voltage isolation conversion circuit is connected to the VCC power supply circuit, and the VCC power supply circuit is respectively connected to the high voltage The high voltage output constant power compensation circuit is connected to the PWM control circuit, and the high voltage output constant power compensation circuit introduces the VCC voltage into the PWM control circuit through a sampling circuit. The PWM control circuit is connected to the low voltage output constant power compensation to introduce the FB voltage of the PWM control circuit into the ground line through a sampling circuit, and the low voltage output constant power compensation is connected to the output end of the circuit through the LED drive and output voltage control circuit and the buck circuit. The buck circuit adopts a dissipative MOS and an LDO linear buck chip to form a double-stage buck power supply circuit to power the display screen module.

[0019] The switching power supply circuit with wide voltage input and output provided in this embodiment has good versatility and strong compatibility.

[0020] Furthermore, a power driving circuit is provided between the input-output voltage isolation conversion circuit and the PWM control circuit.

[0021] Furthermore, a photoelectric isolation feedback circuit is provided between the low voltage output constant power compensation circuit and the LED driving and output voltage control circuit.

[0022] Preferably, it also includes an LED display circuit, which is connected to the LED drive and output voltage control circuit.

[0023] More preferably, it also includes an output voltage sampling circuit, which is connected between the LED driving and output voltage control circuit and the output end of the circuit.

[0024] Preferably, it also includes a touch-type voltage selection key, which is connected to the LED drive and output voltage control circuit.

[0025] It also includes a display screen module driven by the MCU and a light-touch selection key, and a combination of the display screen module driven by the MCU and the light-touch selection key is used to select different output voltages and voltage displays;

[0026] Or it includes a plurality of sets of mechanical pull switches, which are connected to the reference source chip through the downward bias resistors connected in series on the plurality of sets of mechanical pull switches, and different output voltages are selected through the plurality of sets of mechanical pull switches.

[0027] The advantages of the switching power supply circuit provided in this embodiment include but are not limited to:

[0028] (1) The existing switching power supply circuit cannot achieve an ultra-wide output voltage range of 9-48V, while the switching power supply circuit provided in this embodiment achieves an ultra-wide voltage output range of 9-48V by optimizing the transformer structure and turns ratio and adding a stable loop voltage to the feedback loop;

[0029] (2) The existing switching power supply circuit cannot set and select any voltage in the ultra-wide voltage range of 9-48V, while the switching power supply circuit provided in this embodiment can achieve arbitrary setting and selection of any voltage through MCU program control and LED seven-segment display screen, which increases the convenience of operation of the power supply and the user through the display screen, and also increases the interactivity between the power supply and the user;

[0030] (3) The existing switching power supply circuit cannot achieve the consistency of constant current and power limitation at the same time when the ultra-wide voltage output is 9-48V. The switching power supply circuit provided in this embodiment can achieve the consistency of constant current and power in different output voltage segments by adding voltage compensation when the low voltage output is performed and current compensation when the high voltage output is performed.

[0031] (4) The MCU power supply adopts a unique two-stage structure of step-down and voltage regulation, which greatly reduces the power supply cost, greatly reduces the size of the display screen, improves the cost performance, and realizes the modular structure between the display screen and the power supply motherboard, which is convenient for installation and maintenance.

[0032] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A switching power supply circuit with wide voltage input and output, comprising a circuit input end and a circuit output end, between which an AC input voltage doubling rectifier filter circuit, an input and output voltage isolation conversion circuit and an output rectifier circuit are sequentially connected, characterized in that: It also includes a VCC power supply circuit, a high voltage output constant power compensation circuit, a PWM control circuit, a low voltage output constant power compensation circuit, an LED drive and output voltage control circuit and a buck circuit, wherein the input and output voltage isolation conversion circuit is connected to the VCC power supply circuit, the VCC power supply circuit is respectively connected to the high voltage output constant power compensation circuit and the PWM control circuit, and the high voltage output constant power compensation circuit introduces the VCC voltage into the PWM control circuit through a sampling circuit, the PWM control circuit is connected to the low voltage output constant power compensation to introduce the FB voltage of the PWM control circuit into the ground line through a sampling circuit, and the low voltage output constant power compensation is connected to the output end of the circuit through the LED drive and output voltage control circuit and the buck circuit, and the buck circuit adopts a dissipative MOS and an LDO linear buck chip to form a double-stage buck power supply circuit to power the display module.

2. A switching power supply circuit with wide voltage input and output according to claim 1, characterized in that: A power driving circuit is arranged between the input-output voltage isolation conversion circuit and the PWM control circuit.

3. A switching power supply circuit with wide voltage input and output according to claim 1, characterized in that: A photoelectric isolation feedback circuit is provided between the low voltage output constant power compensation circuit and the LED drive and output voltage control circuit.

4. A switching power supply circuit with wide voltage input and output according to claim 1, 2 or 3, characterized in that: It also includes an LED display circuit, which is connected to the LED drive and output voltage control circuit.

5. A switching power supply circuit with wide voltage input and output according to claim 1, 2 or 3, characterized in that: It also includes an output voltage sampling circuit, which is connected between the LED driving and output voltage control circuit and the output end of the circuit.

6. A switching power supply circuit with wide voltage input and output according to claim 1, 2 or 3, characterized in that: It also includes a display screen module driven by the MCU and a light-touch selection key, and a combination of the display screen module driven by the MCU and the light-touch selection key is used to select different output voltages and voltage displays; Or it includes a plurality of sets of mechanical pull switches, which are connected to the reference source chip through the downward bias resistors connected in series on the plurality of sets of mechanical pull switches, and different output voltages are selected through the plurality of sets of mechanical pull switches.

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