12v - 5v LED's

[Da]

I'm looking to buy some LED's and obviously they need to be 12v to work in the cars electrical system.
Anyway the ones I want are listed as 5v so obviously there's resistors I can buy to overcome this but I'm struggling to get my head round it!

Do I need to buy a 12v resistor to limit the DC supply or a 5v resistor for the operating voltage of the LED?? :S

 

[jamojamojamo]

Cant remember the ohm off the top of my head but found a resistor i used to use. Again, its been a while so can only tell you the colours, blue, yellow, black with brown tolerance.

Will try and find more info in a minute

 

[Da]

Thanks, although the resistors I'm looking at aren't grouped according to rating or colourcode. They're listed as voltages, as in 12v 5v 9v etc...


I need 5v equipment to work on a 12v system so do I buy 5v resistors or 12v ones? :S

 

[jamojamojamo]

Depends how it is worded mate, as it maybe in the sense that it will resist 7v of current, which you would want. Or as you have described above

 

[Da]

Yeah that's my confusion mate. I'll link it, 2 mins...

 

[Da]

These are the resistors in question and as above I need to run 5v LED's in my car.

 

[MRBILLYUK]

You'll need 5v resistors . Anything higher will burn out the led if the leds are rated as 5v . Have you got a link to the leds ?

 

[jamojamojamo]

Ok mate, the top two are resistors to make LEDs work on a 12v system i.e. your car battery.

The second one down had a stronger resistance so your LEDs will prob last longer but may not be as bright.

Here's the link to the one im on abouthttp://www.ultraleds.co.uk/single-r....html?osCsid=c9773c626d600038ceef15d4094c6513

 

[Da]

Cheers for the help guys Here is the link to the actual LED's.

So if I'm running 5v LED's on a 12v system I need 12v resistors not 5v ones, am i understanding that correct?

 

[Dink]

what led's are they?

as i don't know of many led's that run off 5v most are normally 3.6v.

+ the resistors are there to current limit mainly

 

[Da]

The LED's are linked above Dink.
Reverse voltage is 5v forward voltage is 3.3v max.

I know the resistors are to limit current predominantly, it's just the description on the site isn't the best.

 

[Dink]

resistor calculator

 

[MRBILLYUK]

What about these Daz . They come supplied with the resistors for a 12v system . Only £1.99 for 10

http://yhst-1250793408186.stores.yahoo.net/ulbrwh303mml.html

 

[Da]

Where does it say they come with resistors MrBilly?

Cheers for the handy calculator Dink!

 

[MRBILLYUK]

So have you got it sussed then Daz ? Sorry mate , they are white , lol . They have some blue ones as well . Just not as bright . Depends what you want the leds for if they are bright enough .

http://yhst-1250793408186.stores.yahoo.net/10ulbrbl353m.html

 

[Dink]

how many leds do you want?

and what you using them for?

as if it's a fair bit of light you want then luxeon stars are the boys

 

[Da]

Ah seen it down at the bottom of the page now!
Almost sussed i think mate cheers, just got to decide on the brightness now!

Dink, I am swapping some internal switch led's on the car. To start with I am doing just 1 or maybe 2 tops. Then we'll see how it goes. Certainly doesn't need a luxeon anyhow

 

[Dink]

lol yeah wouldn't be good being able to see your door locked light from the moon

 

[Da]

Exactamondo! lol

 

[Da]

On a side note, do we think that the led's already fitted in the switches will be 12v rated?
Or will they have built in resistors on the PCB's within the switch?

 

[Dink]

i'd say if you can just take the old led out and fit a new one you wouldn't need to have a resistor as there will already be one in there

 

[Da]

My thoughts exactly, cheers mate!