hey

im aware that you need resistors for led's ive ordered 20 from the net and im not sure on how to work out (coz im useless at maths) what resistors i need for these if anyone could help that would be great ive have these led's sittin in a packet for 6months and i need to make use of them

here are the details of the 2 diffrent types of led's i have

blue 5mm 10,000mCd
white 5mm 20,000mCd

im good with a solidering iron and already have the leds installed and 12v power at each one so what i need is a resistor at each one ...

i found these websites but i cant work out "diode forward voltage"
"diode forward current (mA" as for source voltage that would change depening on the alternator and if the car is even running and what kind of load the elec system is already under
http://led.linear1.org/1led.wiz

thanks
justin

Last edited by Luxo Sprint on Sat Jun 06, 2009 10:23 pm, edited 1 time in total.

give us the voltage/current of each one!

the white 5mm 20,000mCd details are forward voltage 3.5V typical @ 20mA.

i cant seem to find the info on the blues ones .. would they forward voltage be the same as the white ones

does this seem correct krytox

 

 

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?

Wait for him to reply....he knows his stuff.

560ohms is fine, 470 will make it brighter.

and yes, that picture is perfect, bar the ½ watt rating, you only need a ¼.
but get the 5% tolerance ones,

this might help too.

http://answers.yahoo.com/question/index ... 809AAugyTN