CN204836697U - High-efficiency non-isolated circuit for LED illumination - Google Patents

Abstract

The utility model discloses a high-efficient non-isolating circuit for LED illumination, including rectifier bridge Q, resistance R1, electric capacity C1, transformer T1, fuse FU, chip U1 and diode VD1, 220V alternating current one end is connected to fuse FU one end, rectifier bridge Q pin 3 is connected to the 220V alternating current other end, the fuse FU other end is connected to rectifier bridge Q pin 1, electric capacity C4 and inductance L1 are connected respectively to rectifier bridge Q pin 2, rectifier bridge Q pin 4 is connected respectively to the electric capacity C4 other end, electric capacity C5, chip U1' S S end, electric capacity C3, resistance R2 and transformer T1 coil L4, transformer T1 coil L4 other end connecting resistance R1. The utility model discloses a high-efficient non-isolated circuit for LED illumination adopts the inductance non-isolation step-down transformer structure of taking a percentage, and cooperation chip U1 can provide the current multiplication to output for the drive efficiency improves, and circuit structure is simple, and is with low costs, especially adapted using widely.

Description

A high-efficiency non-isolated circuit for LED lighting

technical field

The utility model relates to an LED circuit technology, in particular to a high-efficiency non-isolated circuit for LED lighting.

Background technique

Today, with the energy crisis and climate warming becoming more and more serious, energy conservation and environmental protection have become the focus of social issues. Due to its high efficiency, energy saving, environmental protection, long life, rich colors, small size, flicker resistance, high reliability, convenient control and many other advantages, LED has attracted widespread attention and is considered to be the most promising lighting source in the 21st century. Traditional incandescent lamps have low efficiency and high power consumption; fluorescent lamps save electricity, but their service life is short and fragile, and wastes are polluted by mercury; high-intensity gas discharge lamps have disadvantages such as low efficiency, high power consumption, short life, and electromagnetic radiation hazards ; If the current low-efficiency, high-energy-consuming traditional lighting can be replaced by LED lighting, it will undoubtedly alleviate the current increasingly urgent energy shortage and environmental degradation problems. Due to the volt-ampere characteristics and temperature characteristics of the LED itself, the sensitivity of the LED to the current is higher than the sensitivity to the voltage, so the traditional power supply cannot directly supply power to the LED. Therefore, to use LEDs as lighting sources, the problem of power drive must first be solved. Many existing LED drive circuits use isolation designs, which have complex structures, high costs, and low energy efficiency.

Utility model content

The purpose of this utility model is to provide a high-efficiency non-isolated circuit for LED lighting to solve the problems raised in the above-mentioned background technology.

In order to achieve the above object, the utility model provides the following technical solutions:

A high-efficiency non-isolated circuit for LED lighting, including a rectifier bridge Q, a resistor R1, a capacitor C1, a transformer T1, a fuse FU, a chip U1 and a diode VD1, one end of the fuse FU is connected to 220V AC, and the other One end is connected to the rectifier bridge Q pin 3, the rectifier bridge Q pin 1 is connected to the other end of the fuse FU, the rectifier bridge Q pin 2 is respectively connected to the capacitor C4 and the inductor L1, and the other end of the capacitor C4 is respectively connected to the rectifier bridge Q pin 4, capacitor C5, S terminal of chip U1, capacitor C3, resistor R2 and transformer T1 coil L4, the other end of transformer T1 coil L4 is connected to resistor R1, and the other end of resistor R1 is respectively connected to the other end of resistor R2 and FB terminal of chip U1, BP of chip U1 The other end of the capacitor C3 is connected to the other end of the capacitor C3. The D end of the chip U1 is respectively connected to the capacitor C2 and the coil L2 of the transformer T1. The other end of the capacitor C2 is connected to the other end of the capacitor C5, the other end of the inductor L1, the negative pole of the diode VD1, the capacitor C1, the resistor R4 and the LED light. The positive pole of the string and the negative pole of the LED light string are respectively connected to the other end of the resistor R4, the other end of the capacitor C1 and the coil L3 of the transformer T1, and the other end of the coil L3 of the transformer T1 is respectively connected to the positive pole of the diode VD1 and the other end of the coil L2 of the transformer T1.

As a further solution of the utility model: the diode VD1 is a Zener diode.

As a further solution of the present invention: the model of the chip U1 is LNK6050G.

As a further solution of the utility model: the transformer T adopts a tapped inductor non-isolated step-down transformer structure.

Compared with the prior art, the beneficial effect of the utility model is: the utility model is used for the high-efficiency non-isolated circuit of LED lighting, adopts the structure of the tapped inductance non-isolated step-down transformer, cooperates with the chip U1, and can provide current multiplication for the output, so that The drive energy efficiency is improved, the circuit structure is simple, and the cost is low, which is very suitable for popularization and use.

Description of drawings

Figure 1 is a circuit diagram of a high-efficiency non-isolated circuit for LED lighting.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Please refer to Figure 1, in the embodiment of the utility model, a high-efficiency non-isolated circuit for LED lighting includes a rectifier bridge Q, a resistor R1, a capacitor C1, a transformer T1, a fuse FU, a chip U1 and a diode VD1, and the fuse One end of FU is connected to one end of 220V AC, the other end of 220V AC is connected to rectifier bridge Q pin 3, rectifier bridge Q pin 1 is connected to the other end of fuse FU, rectifier bridge Q pin 2 is respectively connected to capacitor C4 and inductor L1, and the other end of capacitor C4 Connect rectifier bridge Q pin 4, capacitor C5, S terminal of chip U1, capacitor C3, resistor R2 and transformer T1 coil L4, the other end of transformer T1 coil L4 is connected to resistor R1, and the other end of resistor R1 is connected to the other end of resistor R2 and The FB terminal of the chip U1, the BP terminal of the chip U1 are connected to the other end of the capacitor C3, the D terminal of the chip U1 is respectively connected to the capacitor C2 and the coil L2 of the transformer T1, and the other end of the capacitor C2 is respectively connected to the other end of the capacitor C5, the other end of the inductor L1, and the diode VD1 Negative pole, capacitor C1, resistor R4 and the positive pole of the LED light string, and the negative pole of the LED light string are respectively connected to the other end of the resistor R4, the other end of the capacitor C1 and the coil L3 of the transformer T1, and the other end of the coil L3 of the transformer T1 is respectively connected to the positive pole of the diode VD1 and the coil L2 of the transformer T1 another side.

Diode VD1 is a Zener diode.

The chip U1 model is LNK6050G.

The transformer T adopts a tapped inductor non-isolated step-down transformer structure.

The working principle of the utility model is: the chip U1 includes a power switching device (MOSFET), an oscillator, a highly integrated CC/CV control loop, and start-up and protection functions. The MOSFETs provide ample voltage headroom for universal input AC applications including line surges.

The rectifier bridge Q rectifies the 220V AC input, and then the large-capacity capacitor C4 and capacitor C5 filter the rectified DC voltage/current, and the inductor L1, capacitor C4, and capacitor C5 form a π-type filter to eliminate differential mode conducted EMI Noise is attenuated.

After the switch in U1 is turned on, the current will increase and flow through the load LED string and transformer T1 coil L2. Capacitor C1 filters the load current, which eliminates switching elements. Diode VD1 cannot conduct due to reverse bias, and the current continues to increase until it reaches the current limit of U1, once the current reaches the current limit, the switch will be turned off.

After the switch is turned off, the energy stored in the transformer T1 will generate a current and flow into the output part. The current in the coil L2 of the transformer T1 suddenly increases, which improves the driving energy efficiency. LED string lights.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from all points of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to fall within the scope of the claims All changes within the meaning and range of equivalents of the required elements are included in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (4)

1. A high-efficiency non-isolated circuit for LED lighting, comprising a rectifier bridge Q, a resistor R1, a capacitor C1, a transformer T1, a fuse FU, a chip U1 and a diode VD1, wherein one end of the fuse FU is connected to 220V One end of the AC power, the other end of the 220V AC power is connected to the rectifier bridge Q pin 3, the rectifier bridge Q pin 1 is connected to the other end of the fuse FU, the rectifier bridge Q pin 2 is respectively connected to the capacitor C4 and the inductor L1, and the other end of the capacitor C4 is respectively connected to the rectifier bridge Q pin 4, capacitor C5, S terminal of chip U1, capacitor C3, resistor R2 and transformer T1 coil L4, the other end of transformer T1 coil L4 is connected to resistor R1, and the other end of resistor R1 is respectively connected to the other end of resistor R2 and FB of chip U1 The BP end of the chip U1 is connected to the other end of the capacitor C3, the D end of the chip U1 is respectively connected to the capacitor C2 and the coil L2 of the transformer T1, and the other end of the capacitor C2 is respectively connected to the other end of the capacitor C5, the other end of the inductor L1, the negative pole of the diode VD1, and the capacitor C1 , resistor R4 and the positive pole of the LED light string, and the negative pole of the LED light string are respectively connected to the other end of the resistor R4, the other end of the capacitor C1 and the coil L3 of the transformer T1, and the other end of the coil L3 of the transformer T1 is respectively connected to the positive pole of the diode VD1 and the other end of the coil L2 of the transformer T1. 2. The high-efficiency non-isolated circuit for LED lighting according to claim 1, wherein the diode VD1 is a Zener diode. 3. The high-efficiency non-isolated circuit for LED lighting according to claim 1, wherein the model of the chip U1 is LNK6050G. 4. The high-efficiency non-isolated circuit for LED lighting according to claim 1, wherein the transformer T adopts a tapped inductor non-isolated step-down transformer structure.