LED question

[VEN©M]

I want to wire a single white LED into my car, switch is already in place but i'm not sure which LED to use. it needs to be super-bright so can i just get a normal 12V one or do i have to get a lower voltage and use resistors etc..?

it will be wired into an existing circuit which run off car battery

 

[Kerzo]

i thought LED voltages were only about 4v? didnt know you can get 12v ones

 

[VEN©M]

i dunno, can you? thats why i'm asking.

 

[Kerzo]

well that is going back many moons to GCSE technology so times may have changed

 

[James206]

lol. nah 12v deffo doesnt sound rite.

 

[JohnD]

Goto

[url]www.ultraleds.co.uk[/url]


I got some stuff of them and it's very good.

Anthonys Super Blue Boot Installation


This is the white Cav that did the IASCA sound offs over here

 

[James206]

sorry i am talkin *****, 12v yeah u can get them!! sorry

 

[Mark_D]

An LED, on it's own, should not be connected to 12V - it is possible to get 12V LEDs, but these have resistance built in to them.

Formulae below to work out the resistor value required.

The resistor value, R is given by:


R = (VS - VL) / I

VS = supply voltage
VL = LED voltage (usually 2V, but 4V for blue and white LEDs)
I = LED current (e.g. 20mA), this must be less than the maximum permitted


Maplin do a 5mm 8000mcd white LED for £2.99 - code:N29AT

More mcd = more brightness

The are 30mA, so you would probably use a 330ohm resistor.

 

[VEN©M]

ok, so how would u wire it up? ive no clue about electronics really

 

[Lyons]

that andy_gdon chap is the man to ask, sorted me out with some exceedingly cheap LEDs, resistors etc.

 

[VEN©M]

aye but its matching up the resistors etc..

anyways i need an ultra bright white LED that will run off a normal 12v car circuit

 

[Lyons]

lol, the resistor thing has always baffled me, even throughout GCSE and A-level technology. andy also gave me a wee colour chart which explains how many volts each resistor is, still doesnt say "use this one ian", though

i got my previous LED's from maplins, have a look at their website

 

[Mark_D]

Get the LED and I'll sort out the resistor and fitting for you. If you live where I think you live then it's 5 minutes away from my house.
Alternativley, I could draw you a diagram - it's pretty simple.

 

[VEN©M]

lol..where do u think i live then!?

 

[Mark_D]

T'Patrick?

 

[VEN©M]

yes sir, u win a prize. shall i get that white LED from maplins then?

 

[Mark_D]

Aye if it's handy for you. Phone and check they have that model in stock, no point in going all that way for nothing - I picked it because it is very bright.

Before commiting to it though, is 5mm the size you need, or would 3mm be better? Is there an existing hole? will you need to get a clip to hold it in place?

What's the prize btw?

 

[djlee_dj]

i'd say a few quid for all the help :lol:

 

[BigJoe]

.oooppps

 

[excursion]

ya can get 12volt LEDs for about 8£ they are very bright and very reliable. ya can get them pretty much anywhere they sell mod stuff.