AC-LED knowledge summary, AC LED principle and advantages

AC LED structure
The key to the AC LED light source is the special arrangement and combination technology of the LED die during packaging. At the same time, the diode characteristics of the LED PN junction are used as rectification, and multiple die are integrated on a single chip through a semiconductor fabrication process, that is, a high power single. Single power chip LED technology, and a staggered matrix arrangement process to form a bridge circuit, so that the AC current can be bi-directional to achieve illumination. The arrangement of the crystal grains is shown in the figure. The left figure shows the staggered matrix arrangement of the AC LED dies. The right small picture shows the actual AC LED array arrangement. The AC LED dies are illuminated after the AC is connected. It takes two leads to be introduced into the AC source to work.

How AC LEDs work
The working principle of the AC LED is shown in the figure. The LED micro-die adopts an interlaced matrix arrangement process to form five bridge arms, which are similar to a rectifier bridge. The two ends of the rectifier bridge are respectively connected to the AC source, and the other ends are connected to a group. LED dies, the positive half of the alternating current flows along the solid line, the LED dies of the three bridge arms illuminate, the negative half cycle flows along the dotted line, the LED dies of the three bridge arms illuminate, the negative half cycle flows along the dotted line, and there are three bridges The LED dies of the arm emit light, and the LED dies on the four bridge arms illuminate in turn, and the LED dies on the bridge arms simultaneously emit light, and the LED dies of the intermediate bridge arms are always illuminated due to sharing.

AC LED features
1. Heat dissipation improvement
The AC LED uses a three-dimensional heat conduction design, which is more than 10 times more than the thermal contact area of ​​the traditional packaging method, which greatly improves the heat dissipation effect.
2. Improvement of energy loss
AC LED is a brand-new LED operation concept, which has a wide range of functions such as no need for additional rectification transformer circuit, low circuit energy loss (15~30% power loss when AC power is converted), and anti-static shock. In addition to the application value, the unique bridge chip design also greatly increases the light-emitting area of ​​the AC LED die, improving the luminous efficiency.
3. Improvement of light decay
Another difference between AC LED technology and DC LED or traditional light source is that if some tiny LEDs in the die are not damaged, the voltage used in these tiny LEDs will be distributed to the remaining functioning tiny LEDs. The brightness is increased, so even if some of the tiny LEDs are broken, there will be no serious difference in brightness. This is quite different from the case where a DC LED burns out and causes other LEDs to heat up and then short-circuit. Unlike ordinary people's perception of light source light decay.

Advantages of AC LED
The LED is small in size and can be applied to small indicators for industrial and civil use. The advantages of high voltage and low current conduction overcome the problem of relying on the power supply connection when the DC LED is used, and the double-conducting, blue-green LED is not available. Electrostatic breakdown of ESD problems; the use of micro-grain technology to significantly improve luminous efficiency; due to power factor improvement and low current control, for the general lighting industry and LCD display industry, is a practical new technology.