[Nailimixam]

I bought some 3v LED, connected to 2 AA batteries. 1 AA battery = 1.2v, 2 AA batteries = 2.4v.......and it only last a few seconds than a pop sound .....

What am I doing wrong here?

[mr1350]

好似串支電阻做限流至得.

[pongyee]

>> What am I doing wrong here?

you've gotten some poor quality led bulbs.

i had a china made energy saving bulb "pop" and dead some few days ago, it only lasted for a week, ouch.

[Nailimixam]

>>> 定 係 wrong polarity 啦

if your pic is correct then I am correct too....
i am using NiMH, 1.25x2 still only 2.5
but on the battery its written 1.2v

>>>>you've gotten some poor quality led bulbs.
>>>those 3v LED must be CHINA product
>>>>好似串支電阻做限流至得.

I tried using a 3v 100ma power converter and it's working.....

[Douglaschow]

聽日覆你..........! e+ 睇緊波! 嬴左答你, 輸左唔鬚你!

[oly750]

1) 質 素 差 , 一 係 AA 電 , 一 係 LED 燈

2) 電 鴨 5 穩 定

上 述 全 部 靠 估

[Nailimixam]

Battery is Sanyo white one, quality should be good enough

>>>2) 電 鴨 5 穩 定

as far as I know, most normal led don't required a stable current, as long as it's within the 3v range

or else we can't use button battery to test led before buy ...

>>>>嬴左答你, 輸左唔鬚你!

Spain win jor :)

[Nailimixam]

>>>>咁 應 該 係 好 似 mr1350 話 DRY
要 加 R

guess that's the only solution i got..

[老叟]

總之鴨貨靠彩數囉

[Douglaschow]

1) 正實係 3V LED? 一般LED 3mm, 5mm OD都係2V!
2) + - 極倒轉在3V 絕對唔燒LED.
3) 注意1.5V x 2= 唔等于3V! 新電池1.5V x 10% +, = 1.65V x 2 =3.30V
4) 要加限流電阻, 用 ohm law.
5) 唔關MIC事.

可以PM我!

[Douglaschow]

d2c, 你港德啱!

可參考:

http://www.kingbright.com

[Nailimixam]

Thanks everyone :)

>>>>
1) 正實係 3V LED? 一般LED 3mm, 5mm OD都係2V!
I asked the staff that's why I know....or I think it is

3) 注意1.5V x 2= 唔等于3V! 新電池1.5V x 10% +, = 1.65V x 2 =3.30V
but it's written 1.2v on it.....can it be so over to 1.5+?
it's sanyo, not some cheap battery....

4) 要加限流電阻, 用 ohm law.
yup, the only solution....

[老叟]

始終要用基本法咯

[Douglaschow]

易La,咪用IR +LED

[Nailimixam]

我上次問web cam 點換filter 就係咁用