At the beginning, downlights were designed as a simple, effective and inexpensive method for adjusting the brightness of incandescent light sources. It realizes dimming by limiting the power provided to the load, and only allows the AC power grid to be on for a certain percentage of the time each half cycle. By changing the position of the dimmer, the turn-on period can be changed, thereby controlling the power applied to the load, and finally realizing the change of the light output.

   There are currently two different types of downlights. The leading-edge phase-cut dimmer delays the firing angle after the zero-crossing point, and cuts off the initial part of each half cycle of the alternating current, and only allows the latter part to be turned on. The trailing edge dimmer works in the opposite way, turning on at the initial part of each half cycle of alternating current and turning off at the back part. Cutting-edge dimmers only need to use one active device-a triac-which makes them very cheap, and therefore dominate the entire North American market.

   However, another situation appears in the downlight lighting market. On the one hand, there is almost no demand for dimming in the country, and the foreign markets in North America and Australia have little market growth. Several major chip manufacturers that did dimming by international chip manufacturers are also unwilling to fight, and the pace and intensity of pushing new products are not as good as before. According to domestic IDH manufacturers, NXP’s dimming solution was previously used, but because the price is too expensive, it is no longer competitive in the market. They plan to use low-cost MCUs to develop dimming LED lighting solutions in anticipation of opportunities for cooperation with manufacturers. In the future, the dimming market should not have much room for growth. Whether there will be innovations in dimming LED driver IC technology depends on whether international manufacturers are willing to do this market again.

  These lighting fixtures have been using metal halide lamps, which consume a lot of power, and the effect of introducing LEDs is obvious. Moreover, by adopting long-life LEDs, the frequency of replacement can be reduced, which is a major driving factor for the introduction of LEDs.

The LED penetration rate of bulb type and straight tube type lighting products is still very low, and we estimate that by 2014 it will only reach 8% and 4% respectively. Since the relative price difference between LED lamps and incandescent lamps and fluorescent lamps is relatively large, the speed of popularization in countries and regions outside Japan will be relatively slow.