如何用2粒aa差電推1粒白色超光led?

其實用 2V 都已經可以令白色超光 LED 著, 只是光亮度問題, 用 2V 一定唔會好光, 最好就用 3V 至 3.5V, 但在低電壓原有什麼方法可以推到高壓 LED 而且又有一定亮度呢? 你可以試找一些叫 LED Driver 的 IC, 例如 zetex 的 zxsc310, http://www.zetex.com/3.0/appnotes/design/dn64.pdf
這些 LED Driver 加埋外部電路, 通常會令 LED 高速閃動, 這粒 ZXSC310就會令 LED 有200kHz 閃動, 加埋外部電壓提升路, 就可以用 1.8V 至 3V 推到 4 粒"串聯"(並不是並聯)的 LED, 4 粒 LED 串聯表只著流過 LED 的電流只是 1粒 LED的電流, (4粒 LED 並聯, 1粒用 20mA, 4 粒就會用 80mA, 但是串聯只是用 20mA), 但是要考慮的是LED 串聯後所需的電壓, 但是這電壓這粒 LED Driver 已經會自動控制, 所以並不需理會.
現在市面上亦有很多 LED Driver 可以選擇, 這粒 zxsc310 只是其中一粒, 如你買唔到這粒, 你可以找找鴨記華輝或其他電子零件鋪有冇 LED Driver IC 賣, 但用這些零件前, 要有一定基本的電子認識,

series 2 AA batteries ok, but need 3 group parllar is better more current to give led use longer.

You can put one more battery, equal >3V.
If you want the circuit runs stable, you need something more.

You can buy:
Ultra-bright white LED (Now you have one)
LED-socket (Fit for LEDs)
AA batteries (1 for 1.5V, 2 for 3V, 3 for 4.5V)
Battery clamp (You can find 2s for 3V or 4s for 6V, only for AA)

If you want the LED brighter, use the batteries which are long life and powerful (Example: GP batteries). (This only for green, blue, white, purple...LEDs)
You said that the Ultra-bright white LED light in 3-5V, you answered wrong, only 2V can make it light, 3.5V is the best, over 4.5V will become heat (When you turn it off, you touch it, it is a bit hot). Over 6V is danger.

How to make?
Get 2 pcs of AA batteries (Or 3 pcs of LR44 or AG13 batteries), plug the LED into the LED-socket (Watch out for + and -), and also put the batteries into the battery clamp (Not for AG13 and LR44). The battery clamp and the LED-socket have wires, so you can put them together by connecting the wires (Red for + and black for -). This the chain circuit.

For more, just call me.

兩粒aa電串連就可以了
注意led 的正負