 Wysłany: Nie 4:46, 27 Mar 2011 Temat postu: High productivity design |
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| In response to this target market, currently many major semiconductor manufacturers (including the world-renowned semiconductor manufacturers) have launched their own dimming LED ASIC, but because of the inherent light-emitting principle of LED current dimming LED ASIC available in the market are not yet the case very mature, has its inherent problems, this article will be dimmer view of the current program to make a detailed analysis and present our solution based on MCU dimming.
1 LED light-emitting properties of new technology allows LED current to achieve high power levels, LED power to achieve 1W, and even some to 5W,coffee neon sign, luminous efficiency to achieve 60-85LM / W, this device is called bright LED LED ( HB-LED). Currently we are using LED lighting on the HB-LED, the LED 1W generally choose the way through the series and parallel composition of high-power LED lights,business signs, especially the main series. This LED for 3.4V ± 2%, a forward current of 350mA or so. The - curve shown in Figure 1.1. Figure 1.1 LED? Curve can be seen from Figure 1 that, when added to the voltage across the LED does not meet 3.4V before,restaurant board, with the increase. When added to the LED when the voltage reaches 3.4V, the change is small, increasing the voltage across the LED will only increase the current flowing through the LED, thus changing the LED brightness, LED increased until the maximum (350MA),display signs, LED to achieve maximum brightness. Which has been clamped in (3.4V) or so. |
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