how to convert 12V to 3V for LED light in car !

[khguan]

i use the tiny 1/4w 1k resistor for my LEDs.. 1 for each LED. No problems until today... duno how many years already...

 

[lcchong]

i add only one 1k resistor to 4 LED just now.......

(+ve)--(1k resistor)--(+ve LED -ve)--(+ve LED -ve)--(+ve LED -ve)--(+ve LED -ve)--(-ve)

not so bright already..... shud hav buy the adjustable resistor.... then can play with the brightness... LOL

 

[khguan]

not like that la... duh...

 

[lcchong]

sifu, LED very dim already after add resistor laa.....

 

[khguan]

1 resistor for each LED. And the LEDs are connected in series with the resistors only. So each LED n resistor takes direct 12V...

 

[lcchong]

thnx 4 da recommendation......!

 

[donCityZ]

i add only one 1k resistor to 4 LED just now.......

(+ve)--(1k resistor)--(+ve LED -ve)--(+ve LED -ve)--(+ve LED -ve)--(+ve LED -ve)--(-ve)

not so bright already..... shud hav buy the adjustable resistor.... then can play with the brightness... LOL

wah lidat is wrong mah.. that would make only arnd 0.1V~1V across resistor.. so, current = 0.1/1000 = 0.1mA wor.. so current arnd 0.1mA-1mA no wonder la so dim.........