CN211531388U

CN211531388U - LED drive circuit

Info

Publication number: CN211531388U
Application number: CN202020443292.7U
Authority: CN
Inventors: 闵璇皓蓝; 闵长伟; 胡爱斌
Original assignee: Shenzhen Deled Led Co ltd
Current assignee: Shenzhen Deled Led Co ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2020-09-18
Anticipated expiration: 2030-03-31

Abstract

The utility model provides a LED drive circuit, it includes rectifier chip BR1, electric capacity EC1, EC2, inductance L1, common mode inductance L2, power inductance L3, diode D1 and LED driver chip BP2886B, rectifier chip BR 1's positive pole output termination inductance L1's one end, inductance L1's the other end is through the positive pole link LED +, electric capacity EC1 is connected between rectifier chip BR 1's positive pole output and ground, electric capacity EC2 is connected between rectifier chip BR 1's positive pole output and ground, pin 4 of chip BP 86B connects rectifier chip BR 1's positive pole output, pin 5 of chip BP2886 loops through power inductance L3 and the negative pole link of the secondary side of inductance L2 around the group LED lamp, pin 5 of chip BP 28B still links to each other through diode D1 and inductance L1 and electric capacity EC 2's tie point. The utility model discloses a LED drive circuit need not to trun into the alternating current to the constant voltage direct current and can light the LED lamp.

Description

LED drive circuit

Technical Field

The utility model relates to a LED field especially relates to a LED drive circuit.

Background

With the development of LED desk lamps, the miniaturization and simplification of the volume of the desk lamp is a trend. In addition, in order to meet the health requirements of consumers, optical tests on the table lamp are becoming more and more strict, especially in the aspects of the optical power, stroboflash, blue light hazard and electromagnetic radiation index of the table lamp.

Based on the wide demand of intelligent dimming products, if power can be supplied only through an external adapter, the application has great limitation on cost and scenes, and what the market needs is a driving power supply scheme which can not convert AC power into constant voltage DC and then convert the constant voltage DC into a lighted LED.

SUMMERY OF THE UTILITY MODEL

The utility model discloses an overcome prior art's LED drive circuit need turn into AC electricity to constant voltage DC just can light LED's technical problem, provide a LED drive circuit.

In order to achieve the above purpose, the utility model provides a technical scheme as follows:

an LED driving circuit comprises a rectifying chip BR1, capacitors EC1, EC2, an inductor L1, a common mode inductor L2, a power inductor L3, a diode D1 and an LED driving chip BP2886B, wherein the positive electrode output end of the rectifying chip BR1 is connected with one end of the inductor L1, the other end of the inductor L1 is connected with the positive electrode connecting end of an LED lamp through the primary winding of the common mode inductor L2, the negative electrode output end of the rectifying chip BR1 is grounded, a capacitor EC1 is connected between the positive electrode output end of the rectifying chip BR1 and the ground, a capacitor EC2 is connected between the positive electrode output end of the rectifying chip BR1 and the ground, a pin 4 of the chip BP 28B is connected with the positive electrode output end of the rectifying chip BR1, a pin 5 of a chip BP2886 is connected with the negative electrode connecting end of the LED lamp through the secondary winding of the power inductor L3 and the common mode inductor L2 in sequence, and a pin 5 of the chip BP2886 is further connected with the connecting point of the LED 36.

Furthermore, the LED driving circuit further comprises resistors R1 and R2, wherein the resistors R1 and R2 are connected in series between the connection point of the inductor L1 and the capacitor EC2 and the ground.

Further, the LED driving circuit further comprises a resistor R3 connected between the pin 1 of the chip BP2886B and the ground.

Further, the LED driving circuit further comprises resistors R5 and R6 which are connected between the pin 8 of the chip BP2886B and the ground in parallel.

Further, the LED driving circuit further comprises a resistor R4 and a capacitor EC4, wherein the resistor R4 and the capacitor EC4 are connected in parallel between a connection point of an inductor L1 and a capacitor EC2 and a connection point of a power inductor L3 and a secondary winding of a common-mode inductor L2.

Compared with the prior art, the utility model discloses a LED drive circuit can directly convert alternating current commercial power into the luminous power of drive LED lamp, need not trun into the alternating current to constant voltage DC reconvert into drive LED's drive power supply, can also satisfy stroboscopic technical requirement.

Drawings

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

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in 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.

As shown in fig. 1, an embodiment of the present invention provides an LED driving circuit, which includes a rectifying chip BR1, a fuse F1, a capacitor EC1, an EC2, an EC4, an inductor L1, a common mode inductor L2, a power inductor L3, a diode D1, an LED driving chip BP2886B, and resistors R1, R2, R3, R4, R5, and R6.

The input end of the rectifier chip BR1 is connected with a live wire L and a zero wire N of a 220V alternating current power supply respectively. The fuse F1 is connected between the neutral wire N and the input terminal of the rectifier chip BR 1. The positive output end of the rectifier chip BR1 is connected with one end of the inductor L1, and the other end of the inductor L1 is connected with the positive connecting end LED + of the LED lamp through the primary winding of the common-mode inductor L2. The negative output end of the rectifier chip BR1 is grounded. The capacitor EC1 is connected between the positive output end of the rectifier chip BR1 and the ground. The capacitor EC2 is connected between the positive output end of the rectifier chip BR1 and the ground. The capacitors EC1 and EC2 and the inductor L1 form a filter circuit, and the filter circuit is used for rectifying the voltage output by the rectifier chip BR 1. The resistors R1 and R2 are connected in series between the connection point of the inductor L1 and the capacitor EC2 and the ground.

Pin 1 of the chip BP2886B is grounded through a resistor R3, pin 1 is a power supply no-load protection setting pin, and the output no-load voltage can be adjusted according to the size of a pin-to-ground resistor R3. Pin 2 of chip BP2886B is floating. Pin 3 of chip BP2886B is grounded. And the pin 4 of the chip BP2886B is connected with the positive output end of the rectifier chip BR 1. Pin 5 of the chip BP2886B passes through the power inductor L3 and the secondary winding of the common mode inductor L2 in turn to be connected with the negative connection terminal LED-of the LED lamp. Pin 5 of the chip BP2886B is also connected to the junction of the inductor L1 and the capacitor EC2 through a diode D1. The resistor R4 and the capacitor EC4 are connected in parallel between the connection point of the inductor L1 and the capacitor EC2 and the connection point of the power inductor L3 and the secondary winding of the common-mode inductor L2. Pin 6 of chip BP2886B is floating. Pin 7 of the chip BP2886B is connected to the PWM control signal of the LED lamp. The pin 8 of the chip BP2886B is grounded through resistors R5 and R6, respectively, and the maximum current flowing through the LED lamp can be set by the resistances of R5 and R6.

The working principle of the LED driving circuit is as follows:

the L end and the N end are connected with an alternating current mains supply input, and after the input is rectified by BR1, a group of high voltage HV is provided for a chip BP28 2886B pin 4 to supply power to the chip BP2886B pin 4; the voltage HV is simultaneously filtered by EC1, L1, EC 2; the circuit after filtering is divided into two parts, one part is subjected to impedance power-off discharge on a capacitor EC2 through R1 and R2, and the other part flows into a pin 5 of a chip BP2886B through a common-mode inductor L2, an LED +, an LED-, and a power inductor L3. The power inductor L3 is used as a main power inductor, when the U1 pin 5 is switched at a high frequency of tens of kilohertz, the voltage on the power inductor L3 shows the change of voltage polarity, and due to the principle of induced electromotive force of the inductor, the current flows through the LED + and the LED-through the diode D1, so that continuous and non-fluctuating current is provided for the LED lamp.

To sum up, the utility model discloses a LED drive circuit can directly convert alternating current commercial power into the luminous power of drive LED lamp, need not trun into the alternating current to constant voltage DC reconvert into drive LED's drive power supply, can also satisfy stroboscopic technical requirement.

The above description is only exemplary of the present invention and should not be taken as limiting the scope of the present invention, as any modifications, equivalents, improvements and the like made within the spirit and principles of the present invention are intended to be included within the scope of the present invention.

Claims

1. An LED drive circuit is characterized by comprising a rectifying chip BR1, capacitors EC1, EC2 and an inductor L1, the LED driving circuit comprises a common-mode inductor L2, a power inductor L3, a diode D1 and an LED driving chip BP2886B, wherein the positive electrode output end of a rectifying chip BR1 is connected with one end of an inductor L1, the other end of the inductor L1 is connected with the positive electrode connecting end LED + of an LED lamp through a primary winding of the common-mode inductor L2, the negative electrode output end of the rectifying chip BR1 is grounded, a capacitor EC1 is connected between the positive electrode output end of a rectifying chip BR1 and the ground, a capacitor EC2 is connected between the positive electrode output end of the rectifying chip BR1 and the ground, a pin 4 of the chip BP2886B is connected with the positive electrode output end of the rectifying chip BR1, a pin 5 of the chip BP2886B is connected with the negative electrode connecting end LED of the LED lamp through a secondary winding of the power inductor L3 and the common-mode inductor L2 in sequence, and a pin 5 of the.

2. The LED driving circuit according to claim 1, further comprising resistors R1 and R2, wherein the resistors R1 and R2 are connected in series between the connection point of the inductor L1 and the capacitor EC2 and the ground.

3. The LED driving circuit according to claim 1, further comprising a resistor R3 connected between pin 1 of the chip BP2886B and ground.

4. The LED driving circuit according to claim 1, further comprising resistors R5, R6 connected in parallel between pin 8 of the chip BP2886B and ground.

5. The LED driving circuit as claimed in claim 1, further comprising a resistor R4 and a capacitor EC4, wherein the resistor R4 and the capacitor EC4 are connected in parallel between the connection point of the inductor L1 and the capacitor EC2 and the connection point of the power inductor L3 and the secondary winding of the common mode inductor L2.