What is SCR dimming LED lighting?

Introduction: in recent years, with the rise of the global LED commercial lighting market, including China, many LED manufacturers have LED commercial lighting products on the important position of market development. Especially due to the recent Japan, Europe and other major markets of the high efficiency, long life, high power factor, flexible and adjustable light and other aspects of the requirements of LED lighting products, LED driven IC and power industry is facing a new revolution. Therefore, in the next two years, the intelligent dimming LED lamps, especially in the proportion of commercial lighting applications will be expected to be rapidly improved.

At present, the main challenge is that the price of LED light source is declining, but the driving electronic technology has not been a lot of innovation, the price has been high, the cost of pressure. Secondly, due to the current use of LED lighting drive mode, and the existing dimmer voltage dimming, so the challenge of compatibility is quite large. In addition, the power of the thin trend also requires LED drive to have smaller volume. As consumers, LED lighting products need to drive the IC dimming technology to provide consumers with a unique sensory experience.

According to the survey analysis report, the U.S. market is currently a larger demand for light products, almost 100% of dimming products. The European market is less, but also a larger proportion. In addition, the smart LED bulbs this year there may be large-scale commercial. And most of these dimming products are used in conjunction with SCR dimmer. Therefore, it is very meaningful to study the LED lighting products of the silicon controlled dimming.

Silicon controlled dimming

Analysis of the traditional incandescent lamp and halogen lamp dimming system, as compared with the LED lamp, incandescent lamp and halogen lamp is pure resistance device, which means that the current and voltage waveforms it is always the same, when using thyristor dimmer, the input voltage waveform for thyristor conduction angle the change from sine wave, is to change the effective value of the input voltage, it can achieve the purpose of regulating light.

The electrical schematic is shown in figure 1. The dotted line is a silicon controlled dimmer switch mounted on the wall. The resistance between A-B is incandescent lamp load. Therefore, the thyristor switch is directly connected with the load.

Fig. 1 circuit diagram and waveform diagram of SCR dimming

The silicon controlled potentiometer is provided with a switch which is connected with the input end of the n to control the switch of the lamp. In the conduction process of silicon controlled rectifier, it can change the effective voltage of the output voltage by changing the partial voltage ratio of the internal adjustable resistor and changing the conduction angle. In addition to SCR, as well as the transistor front, back dimming technology, the basic principles are similar.