LED's

[DNA666]

How many Blue LEDS did you use? I had to use 5 to make it look legit. 1 in each circle that holds a dial and then 2 at the bottom to properly light the lever and both pics associated with it.

 

[goalieman24]

back to my problem... could someone look at the wiring i did by using the link i posted before and tell me whats wrong

 

[ootalipseoo]

Heres what I did Kinda

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[FiReBReTHa]

Originally posted by ootalipseoo
Heres what I did Kinda

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[goalieman24]

so make a fork in the power wire and run each to a resistor?? correct
is it possible to have too big of a resistor for the led?

 

[Chuckt]

Running it like you did made it so one resistor had too much resistance and therefore wouldnt work. You can splice off as much as you want, as long as its before the resistor.

 

[dynatos]

i only used one LED for that (the bright RadioShack 273-316 one... you can run multiple LEDs off of one resistor, or branch the power leads before and use multiple resistors..

here is a calculator to calculate the resistor needed for LEDs in series.. http://wolfstone.halloweenhost.com/TechBase/litled_LEDCalc.html

hope this helps!

 

[gsx tryin' 4 hp]

Originally posted by dynatos
i only used one LED for that (the bright RadioShack 273-316 one... you can run multiple LEDs off of one resistor, or branch the power leads before and use multiple resistors..

here is a calculator to calculate the resistor needed for LEDs in series.. http://wolfstone.halloweenhost.com/TechBase/litled_LEDCalc.html

hope this helps!

this is for series, but what if u wire in paralell won't this affect the voltage drop or does it affect resistance too?

 

[LightningGSX]

In Parallel the voltage drop will stay the same but you have to multiply foward current by the number of LED's.So if you are using three 3 volt 25 mA LED's in parallel with the series calculator, your voltage drop is 3 volts, your forward current is 75mA, and your number of LED's is one.If you use multiple LED's with a single resistor you will definately need a 1/2 watt or a 1 watt or greater, which I don't think RS will have, so you are better off using a single resistor for each LED.

 

[dynatos]

RS has 1/4 and 1/2 watt available.. Though, as i'm running into doing this project - some house the blue light better. For instance, the AC button has nothing in the way and i can get the blue led in there perfect, where as the FogLight button, i have to put in back.

Basically, i'l have to drop the LED in the AC button more than 560 ohms because of it getting more blue light than some other housings.

So having indepenent power leads for each might prove prudent, because you might want to dim just one LED to get it to match the others.

 

[FiReBReTHa]

im getting baffled.


i have a setup for like 440 resistors for each individual LED on the POS leg,


I then took a single 12V power and branched it off to each resistor, same with the negative, one ground point multiple connections.

Doe sThis Affect Anything???

again, does anyone have an idea what would cause an LED to blink and then die out?

 

[dynatos]

it doesn't affect a single thing. The entire car runs like that, if you think about it. LEDs blink and go out (smell like electrical burn) when they get to much voltage. If you are running a 3.6volt LED with a 440 resistor, you are giving it too much power. Keep in mind in your calculations that a car runs at 13.8, not 12v.

Running all the grounds to one point is fine, probably a lot easier. Having one fused power lead for all the LEDs supply the individual leads with resistors is a good idea too. Though why not just run off of the stock power leads? Replace the bulb with an LED and resistor?

If i'm not making sense or answerring the correct question let me know. Or PM me...

-Dan
(still sticking up for his 2600mcd RadioShack LEDs )

 

[cybershadow]

Where did you purchase your led kit at?

 

[cybershadow]

Originally posted by FiReBReTHa
Whats an LED?

A LED=Light Emitting Diode







http://www.cardomain.com/id/firebretha3

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go to page three, that should help a bit, ive yet to go over it and clean things up. but i hope that helps.

 

[cybershadow]

I don't know if this has any bearing. But I know that in a circuit with a LED, the LED itself drops about 0.7 volts. Does this change anything when hooking them up?

 

[dynatos]

An LED drops the amount of voltage is uses. That is why you need to know the nominal voltage and current ratings to know what Resistor to use. If the LED is using 3.6 volts, and you are supplying it 13.8 - that is 10.2 volts you have to drop. So you take 10.2 and divide by the amperes used, in this case we'll say is uses 20mAh. (20 milliamps is the same as .02 amps)

So 10.2 / .02 = 510

So we need to drop it 510 ohms. Of course, there isn't gonna be an exact resistor available - and also, you want to make room for the car running more than 13.8 - so the next common resistor available is 560.

Hope this makes sense - it's the gool ol' ohms law! V = I x R

 

[FiReBReTHa]

no, they def arent blowin or burning, i wasnt sure if maybe too much power was running them down and slowly eatin em up. yea, i did my math at 12V,

These are my LED's,

SOURCE MATERIAL:InGaN
EMITTING COLOUR:BLUE
LENS TYPE:WATER CLEAR
LUMINOUS INTENSITY-MCD:5000 MIN/ 6000 TYPICAL/7000MAX
REVERSE VOLTAGE:5.0 V
DC FORWARD VOLTAGE:3.3V TYPICAL/ 3.5V MAX
DC FORWARD CURRENT:20mA
VIEWING ANGLE:15
LEAD SOLDERING TEMP:260oC for 5 seconds

My friends have been doing buisness with him for awhile, heres a link to one of his auctions, if you need a custom order just email him like i did. let him know who sent you because i asked him to hookup the people who i knew who i showed my install to, etc.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=26207&item=2595218637

so pretty much my next best option is to get some 560 Resistors and put those on instead of my 440s

now that math calculator is pretty much basing it off multiple LEDs off of one resistor? or wha,

Originally posted by dynatos
it doesn't affect a single thing. The entire car runs like that, if you think about it. LEDs blink and go out (smell like electrical burn) when they get to much voltage. If you are running a 3.6volt LED with a 440 resistor, you are giving it too much power. Keep in mind in your calculations that a car runs at 13.8, not 12v.

Running all the grounds to one point is fine, probably a lot easier. Having one fused power lead for all the LEDs supply the individual leads with resistors is a good idea too. Though why not just run off of the stock power leads? Replace the bulb with an LED and resistor?

If i'm not making sense or answerring the correct question let me know. Or PM me...

-Dan
(still sticking up for his 2600mcd RadioShack LEDs )

 

[FiReBReTHa]

oh yea, i cant replace the stock Lights with LEDs, if you look that picture above with the Needles is mine. i didnt do the bulbs, just the LEDs behind the needles.

now another silly question.

a 440 resistor will allow the diode to glow 7000 MCD
a 660 resistor will allow the diode to glow 5000 MCD

These are just silly figures, because im looking to redo my taillights but i would need a setup like that and a ""switch" im at work and cant remember, but its like relay that controls which direction the power goes, for taillights goes for constant, and when braking the brighter light. im not sure, im still in R&D for this.

 

[cybershadow]

Originally posted by FiReBReTHa

I am not 100% sure, but this wiring looks wrong. You got the LED's in parallel with each other but you only got resisters on one of the LED's. To make it work right I think you would have to put the resistors between the switch and where the two parallel branches meet back up.

 

[FiReBReTHa]

its hard to see the line, his paint pic sux id own it,


its going: switch output, then they branch, each branch has a resistor to each power lead, grounds branch together make single point ground.

 

[dynatos]

I think you are getting Reverse voltage and forward voltage confused. A diode is a one way valve - so it can block 5volts going the wrong way. With a 440 resistor, you are running the LED at 5 volts, which is a LOT more than it can handle, and will pop it.

the 7000 MAX mcd is the LED running at 3.6volts.
the 5000 nominal (still freakin' bright!) is 3.3volts.

Originally posted by FiReBReTHa
oh yea, i cant replace the stock Lights with LEDs, if you look that picture above with the Needles is mine. i didnt do the bulbs, just the LEDs behind the needles.

now another silly question.

a 440 resistor will allow the diode to glow 7000 MCD
a 660 resistor will allow the diode to glow 5000 MCD

These are just silly figures, because im looking to redo my taillights but i would need a setup like that and a ""switch" im at work and cant remember, but its like relay that controls which direction the power goes, for taillights goes for constant, and when braking the brighter light. im not sure, im still in R&D for this.

 

[LightningGSX]

Originally posted by dynatos
An LED drops the amount of voltage is uses. That is why you need to know the nominal voltage and current ratings to know what Resistor to use. If the LED is using 3.6 volts, and you are supplying it 13.8 - that is 10.2 volts you have to drop. So you take 10.2 and divide by the amperes used, in this case we'll say is uses 20mAh. (20 milliamps is the same as .02 amps)

So 10.2 / .02 = 510

So we need to drop it 510 ohms. Of course, there isn't gonna be an exact resistor available - and also, you want to make room for the car running more than 13.8 - so the next common resistor available is 560.

Hope this makes sense - it's the gool ol' ohms law! V = I x R

And to calculate dissipation through the resistor, P=IE.So going with the same example above 10.2 X .02 = .204, You should round up to the next higher wattage rating, So a 1/4 watt resistor should be used.The wattage value should be derated, so if your calculated dissipation is within %10-%20 or so of the next higher wattage resistor, go to the next higher wattage after that one.So if your disipation is say .245, even though it is under a 1/4 watt, go with a 1/2 watt resistor.

 

[16g-95gsx]

I wish to redo the lights on my gauges so that the tachometer and speedometer numbers etc come up white, instead of orange. How would I go about doing that? I have tried to research it, but I cant find any info pertaining to the numbers themselves and how to change their color. Do I want a 3mm LED or 5mm, what about MCD, is 5000max bright enough? I see that picture in this thread of a white LED used but I have no clue what MCD that led was, it looks really faint, I'd like a much brighter light personally. for a 3.3v-3.5vmax LED what resistor am I looking at getting? I am assuming its all running off of 12v correct?

 

[jepherz]

Correction, it doesn't matter if you put the resistor before or after the LED, positive side or not. All you are doing is minimizing the current, which burns the LEDs out. LEDs have very little resistance so that if you just hook them up to 12v with no resistor, gonzoo!