Three types of mainstream LED lighting fixture circuits


After several years of rapid development, various light […]

After several years of rapid development, various lighting fixtures for various uses now basically use LED lighting technology. This emerging lighting technology is vastly different from traditional lighting technologies such as incandescent, fluorescent, and energy-saving lamps. In use, the power consumption of LED lighting fixtures is far lower than traditional lighting fixtures. Compared with traditional lighting fixtures, it can be said that it is an epoch-making new technology, so it is rapidly replacing traditional lighting fixtures in most occasions. Just like the gap between digital cameras and film cameras, the gap between LED lamps and traditional lamps is also huge.

However, in recent years, due to fierce competition, the market for LED lighting fixtures has been fierce. The brand of LED lamps on the market varies, and there are large differences in price and quality. The price of the same product of different brands is even several times different. In this market environment, it has brought huge inconvenience to consumers to choose a suitable LED lamp.

Therefore, today introduces the internal circuits of the three types of LED lighting fixtures that are mainstream in the market, which is convenient for consumers to use as a reference when selecting various types of LED lighting fixtures. "Yiliang Lighting" is an emerging LED lighting brand mainly focusing on LED downlights. It adhered to the principle of "stabilizing circuits and using more materials". In the early days, it was called "LED lamps that more electronic engineers like." In addition, he proposed the "high-performance LED lamp" and became the representative brand of "high-performance downlight". In a short time, he gained a high position in the LED downlight market.
The first category: resistance capacitance buck

This type of circuit uses a small-capacity power supply with resistance-capacitance and step-down voltage to power the LED string of beads, driving the string of LED beads, and making the string of beads shine.

The main principle is to reduce the input voltage through resistance-capacitance step-down, and then pass a rectifier bridge, a filter capacitor, a zener tube and other components to obtain a direct current that can cause the LED lamp bead string to emit light. The biggest advantage of this kind of circuit is that the cost is very low. However, the shortcomings are also obvious. The most fatal shortcomings, such as severe strobe and short life, are all in one. This is a circuit that should be eliminated on LED lights, but due to fierce competition, the profit of LED lamps has been reduced to as thin as a piece of paper, and the competition continues to increase, so many LED lamp companies have to restart Use this circuit that should have been eliminated. This is also one of the reasons that the prices of the same products of different brands mentioned above are even several times different. It is normal for a constant current circuit to be several times different from the selling price compared to a resistor-capacitor buck circuit.

The second category: constant current power drive

This type of circuit uses a constant-current switching power supply to supply power to the LED string lights, and drives the LED string lights to cause the string lights to emit light.

Although the same power supply is used to power the lamp string, the difference between using a constant current power supply and the capacitor-capacitor step-down is very large.The constant current power supply can provide a DC current that is basically constant and can provide a very smooth LED lamp string. Power supply, a well-designed constant current power supply can basically eliminate video flicker, and after several years of constant current chip development, the performance of the constant current power supply can be made higher.This kind of LED lamps have no flicker, high performance, and input voltage. It has a wide range and is also the most used circuit for excellent LED lamps on the market. At the same time, the cost is higher.

In addition, Xiaobian learned that the constant current power supply of LED lights driven by the constant current power supply is divided into two categories, there are isolated constant current power supply and non-isolated constant current power supply. After years of competition and development, mature constant current power supplies have high performance regardless of whether they are isolated or non-isolated. "Yiliang Lighting" indicates that they use an isolated constant current power source for driving such downlights that are separated from the light source, and use non-isolated constant current power supplies for driving such downlights that are integrated with the light source. Because the split-type downlight may touch the power output during the installation, the first-stage isolated driving power supply is safer, and the integrated downlight will not directly contact the power output during the installation. End, and non-isolated power often has higher efficiency and lower heat generation than isolated power, so it is more suitable for integrated downlights.

The third category: linear constant current

This type of LED lamp circuit is a new type of LED lighting lamp circuit solution developed in recent years. It directly rectifies the 220VAC input AC power and then passes the chip constant current to power the LED lamp bead string to make the LED lamp string shine.

A well-designed linear constant current LED lamp has many advantages such as long life, high performance, high efficiency, no video flash, and strong electromagnetic compatibility.The disadvantage is that the input voltage range is narrower than the constant current power supply. If the input voltage changes greatly The brightness of the output may also change slightly (not easy to observe with the naked eye).

In addition, the same type of circuit LED lamps may have a large cost difference, because for such circuits to have higher performance, the total voltage of the LED lamp beads string to be used is higher. Due to the product volume limitation, a single voltage is generally used. High-performance LED lamps need high cost to complete the high-performance lamps with the circuit.

The above are the three types of internal circuits of mainstream LED lighting fixtures that have been sorted out after editing. It can be seen that if the performance is high, there is no flicker, and the life is long, the cost of the circuit that needs to be used will be higher, and if the price is lower, you must use a resistor-capacitor buck circuit with serious flicker and low performance. Therefore, there is a reason that the prices of different brands of LED lamps on the market are very different. Consumers need to choose different LED lamps according to their needs.

Three types of mainstream LED lighting fixture circuits