阅读说明：本技术 一种led驱动电路和led电源 (LED drive circuit and LED power ) 是由 周辉志 于 2019-08-30 设计创作，主要内容包括：本发明属于电源技术领域,提供了一种LED驱动电路和LED电源。LED驱动电路连接LED模组,LED驱动电路包括：第一采样模块、第二采样模块、基准电压生成模块、反馈模块、控制模块以及电压转换模块。第一采样模块用于根据驱动电源生成电压采样信号；第二采样模块用于根据所述驱动电源生成电流采样信号；基准电压生成模块用于根据所述电压采样信号生成第一基准电压；反馈模块用于根据所述第一基准电压和所述电流采样信号生成反馈信号；控制模块用于根据所述反馈信号生成控制信号；电压转换模块用于根据控制信号将输入电压转换为驱动电源以驱动所述LED模组。(The invention belongs to the technical field of power supplies, and provides an LED driving circuit and an LED power supply. LED drive circuit connects the LED module, and LED drive circuit includes: the device comprises a first sampling module, a second sampling module, a reference voltage generating module, a feedback module, a control module and a voltage conversion module. The first sampling module is used for generating a voltage sampling signal according to the driving power supply; the second sampling module is used for generating a current sampling signal according to the driving power supply; the reference voltage generating module is used for generating a first reference voltage according to the voltage sampling signal; the feedback module is used for generating a feedback signal according to the first reference voltage and the current sampling signal; the control module is used for generating a control signal according to the feedback signal; the voltage conversion module is used for converting the input voltage into a driving power supply according to the control signal so as to drive the LED module.)

1. An LED drive circuit, connect LED module, its characterized in that, LED drive circuit includes:

the first sampling module is used for generating a voltage sampling signal according to the driving power supply;

the second sampling module is used for generating a current sampling signal according to the driving power supply;

the reference voltage generating module is connected with the first sampling module and used for generating a first reference voltage according to the voltage sampling signal;

the feedback module is connected with the second sampling module and the reference voltage generating module and used for generating a feedback signal according to the first reference voltage and the current sampling signal;

the control module is connected with the feedback module and used for generating a control signal according to the feedback signal;

and the voltage conversion module is connected with the control module and used for converting the input voltage into a driving power supply according to the control signal so as to drive the LED module.

2. The LED driving circuit according to claim 1, further comprising:

and the input module is connected with the voltage conversion module and used for generating input voltage according to an input commercial power supply.

3. The LED driving circuit according to claim 2, wherein the input module comprises:

the low-pass filtering unit is used for performing low-pass filtering processing on the commercial power;

and the rectification filtering unit is connected with the low-pass filtering unit and used for generating the input voltage according to the commercial power after the low-pass filtering processing.

4. The LED drive circuit of claim 1, wherein the first sampling module comprises: a first sampling resistor and a second sampling resistor;

the first end of the first sampling resistor is the input end of the driving power supply of the first sampling module, the second end of the first sampling resistor is grounded through the second sampling resistor, and the common connection end of the first sampling resistor and the second sampling resistor is the output end of the voltage sampling signal of the first sampling module.

5. The LED driving circuit of claim 1, wherein the second sampling module comprises: the third sampling resistor, the fourth sampling resistor and the fifth sampling resistor;

the first end of third sampling resistance does the drive power supply input of second sampling module, the second end of third sampling resistance is connected the LED module, the first end of fourth sampling resistance is connected the first end of third sampling resistance, the second end of third sampling resistance is connected to the first end of fifth sampling resistance, the second end of fourth sampling resistance with the second end of fifth sampling resistance does the current sampling signal output of second sampling module.

6. The LED driving circuit according to claim 1, wherein the reference voltage generating module includes: the circuit comprises a first operational amplifier, a first capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor;

the positive phase end of the first operational amplifier is a second reference voltage input end of the reference voltage generation module, the inverting end of the first operational amplifier is a voltage sampling signal input end of the reference voltage generation module, the output end of the first operational amplifier is connected with a first end of the first resistor, a second end of the first resistor is connected with second reference voltage through the second resistor, the second end of the first resistor is connected with a first end of the fourth resistor through the third resistor, the first end of the fourth resistor is grounded through the fifth resistor, the second end of the fourth resistor is grounded through the first capacitor, the second end of the fourth resistor is connected with a first end of the sixth resistor, and the second end of the sixth resistor is a first reference voltage output end of the reference voltage generation module.

7. The LED drive circuit of claim 1, wherein the feedback module comprises: a second operational amplifier;

the positive phase end of the second operational amplifier is a first reference voltage input end of the feedback module, the negative phase end of the second operational amplifier and the positive phase end of the second operational amplifier are current sampling signal input ends of the feedback module, and the output end of the second operational amplifier is a feedback signal output end of the feedback module.

8. The LED driving circuit according to claim 1, further comprising:

the auxiliary power supply module is connected with the input module and used for generating auxiliary voltage according to the input voltage;

the control module specifically generates a control signal according to the auxiliary voltage and the feedback signal; the auxiliary power supply module includes: the power supply conversion chip and the first transformer are connected;

the first end of the primary coil of the first transformer is an input voltage input end of the auxiliary power supply module, the control end of the power conversion chip is connected with the second end of the primary coil of the first transformer, the first end of the secondary coil of the first transformer is an auxiliary voltage output end of the auxiliary power supply module, and the second end of the secondary coil of the first transformer is grounded.

9. The LED driving circuit according to claim 1, wherein the control module comprises a control unit, a photo-isolation tube and a first diode;

the negative electrode of the first diode is a feedback signal input end of the control module, the positive electrode of the first diode is connected with the negative electrode of the illuminator of the photoelectric isolation tube, the positive electrode of the illuminator of the photoelectric isolation tube is an auxiliary voltage input end of the control module, the first end of the light receiving end of the photoelectric isolation tube is connected with the feedback end of the control unit, and the second end of the light receiving end of the photoelectric isolation tube is grounded.

10. An LED power supply, connect LED module, its characterized in that, LED power supply includes: an LED driver circuit as claimed in any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of power supplies, and particularly relates to an LED driving circuit and an LED power supply.

Background

The Forward Voltage (VF) of different LED light sources is greatly different, and the LED light sources with the same combination may also have a large deviation in different batches or different manufacturers VF. Therefore, when a common constant current power supply is used, the input power of the whole LED lamps in the same batch is greatly different; under the series and parallel relations of the LED light sources with different combinations, the VF of the LED is larger, and power supply products with various current specifications are required to meet the requirements, so that customers are required to prepare power supplies with various specifications, and the cost is increased; there is also difficulty in selecting a power supply, and a professional is required to match the LED with a corresponding power supply through a test device.

In the current market, a Micro Control Unit (MCU) is used for constant power design, two pins of the MCU are used for detecting a power driving voltage and an output current value, and a corresponding Pulse Width Modulation (PWM) signal is output to a control loop through MCU multiplication to realize output constant power adjustment, so that the MCU and a power supply circuit thereof need to be added to the circuit, resulting in complicated circuit, and personnel needing to understand a digital circuit and an analog circuit can realize power development.

Therefore, the conventional constant power driving technical scheme has the problems of high circuit development difficulty and increased cost.

Disclosure of Invention

The invention aims to provide an LED driving circuit and an LED power supply, and aims to solve the problems of high circuit development difficulty and high cost in the traditional constant power driving technical scheme.

An LED drive circuit, connect the LED module, the LED drive circuit includes:

the first sampling module is used for generating a voltage sampling signal according to the driving power supply;

the second sampling module is used for generating a current sampling signal according to the driving power supply;

the reference voltage generating module is connected with the first sampling module and used for generating a first reference voltage according to the voltage sampling signal;

the feedback module is connected with the second sampling module and the reference voltage generating module and used for generating a feedback signal according to the first reference voltage and the current sampling signal;

the control module is connected with the feedback module and used for generating a control signal according to the feedback signal;

and the voltage conversion module is connected with the control module and used for converting the input voltage into a driving power supply according to the control signal so as to drive the LED module.

In one embodiment, the method further comprises the following steps:

and the input module is connected with the voltage conversion module and used for generating input voltage according to an input commercial power supply.

In one embodiment, the input module comprises:

the low-pass filtering unit is used for performing low-pass filtering processing on the commercial power;

and the rectification filtering unit is connected with the low-pass filtering unit and used for generating the input voltage according to the commercial power after the low-pass filtering processing.

In one embodiment, the first sampling module comprises: a first sampling resistor and a second sampling resistor;

the first end of the first sampling resistor is the input end of the driving power supply of the first sampling module, the second end of the first sampling resistor is grounded through the second sampling resistor, and the common connection end of the first sampling resistor and the second sampling resistor is the output end of the voltage sampling signal of the first sampling module.

In one embodiment, the second sampling module comprises: the third sampling resistor, the fourth sampling resistor and the fifth sampling resistor;

the first end of third sampling resistance does the drive power supply input of second sampling module, the second end of third sampling resistance is connected the LED module, the first end of fourth sampling resistance is connected the first end of third sampling resistance, the second end of third sampling resistance is connected to the first end of fifth sampling resistance, the second end of fourth sampling resistance with the second end of fifth sampling resistance does the current sampling signal output of second sampling module.

In one embodiment, the reference voltage generation module includes: the circuit comprises a first operational amplifier, a first capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor and a sixth resistor;

the positive phase end of the first operational amplifier is a second reference voltage input end of the reference voltage generation module, the inverting end of the first operational amplifier is a voltage sampling signal input end of the reference voltage generation module, the output end of the first operational amplifier is connected with a first end of the first resistor, a second end of the first resistor is connected with second reference voltage through the second resistor, the second end of the first resistor is connected with a first end of the fourth resistor through the third resistor, the first end of the fourth resistor is grounded through the fifth resistor, the second end of the fourth resistor is grounded through the first capacitor, the second end of the fourth resistor is connected with a first end of the sixth resistor, and the second end of the sixth resistor is a first reference voltage output end of the reference voltage generation module.

In one embodiment, the feedback module comprises: a second operational amplifier;

the positive phase end of the second operational amplifier is a first reference voltage input end of the feedback module, the negative phase end of the second operational amplifier and the positive phase end of the second operational amplifier are current sampling signal input ends of the feedback module, and the output end of the second operational amplifier is a feedback signal output end of the feedback module.

In one embodiment, the method further comprises the following steps:

the auxiliary power supply module is connected with the input module and used for generating auxiliary voltage according to the input voltage;

the control module specifically generates a control signal according to the auxiliary voltage and the feedback signal; the auxiliary power supply module includes: the power supply conversion chip and the first transformer are connected;

the first end of the primary coil of the first transformer is an input voltage input end of the auxiliary power supply module, the control end of the power conversion chip is connected with the second end of the primary coil of the first transformer, the first end of the secondary coil of the first transformer is an auxiliary voltage output end of the auxiliary power supply module, and the second end of the secondary coil of the first transformer is grounded.

In one embodiment, the control module comprises a control unit, a photoelectric isolation tube and a first diode;

the negative electrode of the first diode is a feedback signal input end of the control module, the positive electrode of the first diode is connected with the negative electrode of the illuminator of the photoelectric isolation tube, the positive electrode of the illuminator of the photoelectric isolation tube is an auxiliary voltage input end of the control module, the first end of the light receiving end of the photoelectric isolation tube is connected with the feedback end of the control unit, and the second end of the light receiving end of the photoelectric isolation tube is grounded.

In addition, still provide an LED power, with the LED module, the LED power includes: the LED driving circuit is provided.

In the LED driving circuit, the first sampling module is used for sampling the driving power supply and generating a voltage sampling signal, the feedback module is used for generating a first reference voltage according to the voltage sampling signal, the second sampling module is used for sampling the driving power supply and generating a current sampling signal, the reference voltage generating module is used for generating a first reference voltage according to the voltage sampling signal, the feedback module is used for generating a feedback signal according to the first reference voltage and the current sampling signal, the control module is used for generating a control signal according to the feedback signal, and the control voltage conversion module is used for converting the input voltage into the driving power supply to drive the LED module; when a load is replaced, the power of the driving power supply changes, the voltage change of the driving power supply and the current change of the driving power supply are detected through the voltage sampling signal and the current sampling signal, and a feedback signal is generated according to the voltage change of the driving power supply and the current change of the driving power supply, so that the constant power output of a circuit is realized, the adaptability of the power supply is improved, the circuit is simple, the development difficulty is reduced, and the cost of the power supply is reduced.

Drawings

Fig. 1 is a schematic structural diagram of an LED driving circuit according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an input module of the LED driving circuit shown in FIG. 1;

FIG. 3 is a schematic circuit diagram of a portion of an exemplary LED driver circuit shown in FIG. 1;

fig. 4 is an exemplary circuit schematic of an auxiliary power module in an LED driver circuit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Fig. 1 shows a schematic structural diagram of an LED driving circuit provided in an embodiment of the present invention. As shown in fig. 1, the LED driving circuit is connected to the LED module 2, and the LED driving circuit includes: the circuit comprises a first sampling module 10, a second sampling module 20, a reference voltage generating module 30, a feedback module 40, a control module 50 and a voltage converting module 60. The first sampling module 10 is configured to generate a voltage sampling signal according to a driving power supply; the second sampling module 20 is configured to generate a current sampling signal according to the driving power supply; the reference voltage generating module 30 is connected to the first sampling module 10, and configured to generate a first reference voltage according to the voltage sampling signal; the feedback module 40 is connected to the second sampling module 20 and the reference voltage generating module 30, and is configured to generate a feedback signal according to the first reference voltage and current sampling signal; the control module 50 is connected with the feedback module 40 and is used for generating a control signal according to the feedback signal; the voltage conversion module 60 is connected to the control module 50, and is configured to convert the input voltage into a driving power according to the control signal to drive the LED module.

In this embodiment, the driving power is sampled by the first sampling module 10 to generate a voltage sampling signal, the feedback module 40 generates a first reference voltage according to the voltage sampling signal, the driving power is sampled by the second sampling module 20 to generate a current sampling signal, the reference voltage generating module 30 generates a first reference voltage according to the voltage sampling signal, the feedback module 40 generates a feedback signal according to the first reference voltage and the current sampling signal, the control module 50 generates a control signal according to the feedback signal, the control voltage converting module 60 converts the input voltage into the driving power to drive the LED module, when the load is changed, the power of the driving power is changed, the voltage change of the driving power and the current change of the driving power are detected by the voltage sampling signal and the current sampling signal, and the feedback signal is generated according to the voltage change of the driving power and the current change of the driving power, the circuit constant power output is realized, the power supply adaptability is improved, the circuit is simple, the development difficulty is reduced, and the power supply cost is reduced.

In one embodiment, the LED driving circuit further includes an input module 70, and the input module 70 is connected to the voltage conversion module 60 and is configured to generate an input voltage according to an input mains power. In one embodiment, the input module 70 includes a low-pass filtering unit 71 and a rectifying and filtering unit 72, wherein the low-pass filtering unit 71 is configured to perform low-pass filtering processing on the commercial power; the rectifying and filtering unit 72 is connected to the low-pass filtering unit 71, and is configured to generate an input voltage according to the commercial power after the low-pass filtering processing.

As shown in fig. 2, in one embodiment, the reference voltage generating module 30 includes a first operational amplifier U1, a first capacitor C1, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6; the positive phase terminal of the first operational amplifier U1 is the second reference voltage input terminal of the reference voltage generating module 30, the inverted phase terminal of the first operational amplifier U1 is the voltage sampling signal input terminal of the reference voltage generating module 30, the output terminal of the first operational amplifier U1 is connected to the first terminal of the first resistor R1, the second terminal of the first resistor R1 is connected to the second reference voltage through the second resistor R2, the second terminal of the first resistor R1 is connected to the first terminal of the fourth resistor R4 through the third resistor R3, the first terminal of the fourth resistor R4 is grounded through the fifth resistor R5, the second terminal of the fourth resistor R4 is grounded through the first capacitor C1, the second terminal of the fourth resistor R4 is connected to the first terminal of the sixth resistor R6, and the second terminal of the sixth resistor R6 is the first reference voltage output terminal of the reference voltage generating module 30.

In one embodiment, the feedback module 40 includes a second operational amplifier U2; the positive phase terminal of the second operational amplifier U2 is a first reference voltage input terminal of the feedback module 40, the inverting terminal of the second operational amplifier U2 and the positive phase terminal of the second operational amplifier are current sampling signal input terminals of the feedback module 40, and the output terminal of the second operational amplifier U2 is a feedback signal output terminal of the feedback module 40.

In one embodiment, the control module 50 includes a control unit, a photo isolator tube U3, and a first diode D1; the cathode of the first diode D1 is a feedback signal input end of the control module 50, the anode of the first diode D1 is connected to the cathode of the light emitter of the photo-isolation tube U3, the anode of the light emitter of the photo-isolation tube U3 is an auxiliary voltage input end of the control module 50, the first end of the light receiving end of the photo-isolation tube U3 is connected to the feedback end of the control unit, and the second end of the light receiving end of the photo-isolation tube U3 is grounded. The control unit comprises a switching power supply chip, and the power supply conversion module comprises a transformer.

In one embodiment, the first sampling module 10 includes a first sampling resistor R7 and a second sampling resistor R8; the first end of the first sampling resistor R7 is the driving power input end of the first sampling module 10, the second end of the first sampling resistor R7 is grounded through the second sampling resistor R8, and the common connection end of the first sampling resistor R7 and the second sampling resistor R8 is the voltage sampling signal output end of the first sampling module 10.

In one embodiment, the second sampling module 20 includes a third sampling resistor R9, a fourth sampling resistor R10, and a fifth sampling resistor R11; the first end of the third sampling resistor R9 is the driving power input end of the second sampling module 20, the second end of the third sampling resistor R9 is connected to the LED module 2, the first end of the fourth sampling resistor R10 is connected to the first end of the third sampling resistor R9, the first end of the fifth sampling resistor R11 is connected to the second end of the third sampling resistor R9, and the second end of the fourth sampling resistor R10 and the second end of the fifth sampling resistor R11 are the current sampling signal output end of the second sampling module 20.

As shown in fig. 3, in one embodiment, the LED driving circuit further includes an auxiliary power module 80, and the auxiliary power module 80 is connected to the input module 10 for generating an auxiliary voltage according to the input voltage. In one embodiment, the auxiliary power module 80 includes a power conversion chip U4, a first transformer T1; the first end of the primary winding of the first transformer T1 is an input voltage input end of the auxiliary power module 80, the control end LX of the power conversion chip U4 is connected to the second end of the primary winding of the first transformer T1, the first end of the secondary winding of the first transformer T1 is an auxiliary voltage output end of the auxiliary power module 80, and the second end of the secondary winding of the first transformer T1 is grounded.

In addition, still provide an LED power, connect LED module 2, the LED power includes: the LED driving circuit is provided.

Fig. 2 is explained below in conjunction with the circuit principle:

the forward voltages of different LED light sources have large difference, and when the LED module 2 connected to the LED driving circuit is changed, the driving power supply output by the LED driving circuit is also changed, so that the requirement of constant power output cannot be met.

Therefore, in this embodiment, when the LED module 2 connected to the LED driving circuit changes, the driving voltage is sampled by the first sampling resistor R7 and the second sampling resistor R8 to generate a voltage sampling signal, the first operational amplifier U1 generates a first reference voltage according to the voltage sampling signal and outputs the first reference voltage to the positive phase end of the second operational amplifier U2 through the first capacitor C1, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6, the second operational amplifier U2 generates a feedback signal according to the first reference voltage and the current sampling signal and outputs the feedback signal to the feedback end of the control module 50 through the photoelectric isolation tube U3, and the control module 50 outputs a control signal according to the feedback signal and controls the voltage conversion module to generate the driving power supply of the constant power.

Specifically, when the LED module 2 changes from the first load to the second load, the voltage of the driving power is changed from the original driving voltage U1 to the unsteady driving voltage U2 ', the current of the driving power is changed from the original driving current I1 to the unsteady driving current I2', the first sampling module 10 and the second sampling module 20 respectively sample the unsteady driving voltage U2 'and the unsteady driving current I2' to generate a voltage sampling signal and a current sampling signal, the first operational amplifier U1 generates a corresponding first reference voltage according to the voltage sampling signal, the second operational amplifier U2 generates a feedback signal according to the first reference voltage and the current sampling signal, and the control module 50 generates a changed control signal according to the feedback signal to control the output of the new driving power by the voltage conversion unit, wherein the target driving voltage U2 of the new driving power and the target driving current I2 of the new driving power are multiplied by (a I.e., the power of the new driving power supply) is equal to the product of the original driving voltage U1 and the original driving current I1 (i.e., the power of the driving power supply at the time of the first load), thereby realizing the constant power output of the circuit and improving the power supply adaptability.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.