Custom L.E.Ds

[Bedfordcrazy]

Hi Guys, once again i need help from the beddy family. I have a really hot set of tail lights for my van, but i want HOT not just hot. So here is what i want, i want to find someone that can build an LED card to fit inside my tail lights. I have searched the net, and like normal, if i was a yank no problem, but here in oz i can not find anyone, whats new. Is there someone on here that can point me in the right direction. I know what i want, just need someone hopefully in brisbane that i can take my lights to, and they can do it all.

                                HELP

george

[BusyKiwi]

A mate of mine got all LED replacement bulbs for his 68 Pontiac a couple of months ago, I remember him saying it was cheaper to get them all at once and the postage from USA was very reasonable. He got full set, including dash ones

I'll try get hold of him and find out the name of the place

[Rogue Trooper]

I've bought them from here before. Had reasonable service. Might be something here you could adapt.

http://www.superbrightleds.com/

I hope you've got one eye on the cup while you're on here Busy. I love my TV card.

[ShaneJ]

George, what about just some veroboard cut to shape and solder all your leds on? This is what I am planing on doing for my Celica. I might be able to help you out if this will work.

Shane

[Bedfordcrazy]

Bingo shane, that is what i am looking for, i want to create my own led pattens and flash patterns and so on. Being that tail lights are a priority for safety i did not feel comfortable doing it. Also my lenses need to be sliced open and rewelded, so wanted a professional looking finish. I can find the plastic welders, but the led side of things. I have one call to make shortly, so i will let you know how that pans out.

Hey busy and rogue, i have a few contacts here that sell the led replacement bulbs, but i wanted to change the way the lights look when they are activated, so what shane is looking at is spot on. You can have the brakes as rings, indicators as yellow arrows, the imagination is the only limit, take a look.
I cant believe no one in bris does that sort of thing, or maybe i do.

george.

[BusyKiwi]

I've never seen that done, interesting

[ShaneJ]

The problem George is that every design would have to go through DOT testing for them to be legal. This would make it difficult for a business to be able to offer custom designs.

[Bedfordcrazy]

Hi shane, mate i suspect that because i am already using a factory set of lights, body/lens, so long as the L.E.Ds respond when activated, their not to know the leds are not factory. I will be making sure the brakes are bright, try and dazzel them. 
Ok i spoke to my sparky and he can do them, BUT he recons for him to do them from scratch would be pricy. He told me that there are companies that do it, they can knock up the circuit board and leds using a computer, i am BUGGERED if i can find who does it. Yank web sites have dozens of places that do it, looks like i might have to move to yankland.  Here are some pics i found from yankland, you can not spot the custom unless you pull the light apart, i guess so long as the relevent lights work when they are supposed to, then no one should be the wiser.

Looks like i may have found a new business, do a course and create my own lights. 

george

[Warren]

George

Its not that hard, just a bit of understanding, planning and maths.

You need to know the specs of the LED's, there voltage and current ratings and what configuration your going to use.

lets take a simple example, you want a high beam indicator.

You have a "Blue" LED with specs of 4 volts and max current rating of 500milimamps.

You are going to feed it of a 12 volt power source. thats 3 times the voltage you need, so how do you get just 4 volts?

You have to use the rest of the power somewhere else, in a dropping resistor.

Using the Ohm's law formula V = I x R where V is volts, I is current in amps and R is resitence and the specs of the LED we can work out what size resistor we need.

See http://en.wikipedia.org/wiki/Ohm's_law for more info

For this simple cct the resistor is connected with the LED in a line from the +ve to the -ve (this is called a series cct), the maximum rate of current in the circuit is defined/controlled by the max amperage of the LED.

So for V we need 12 - 4 = 8.

We know the max amps as 500 milliamps

So we know 2 of the 3 values and transposing the formula to R = V divided by I, plugging the values in to the forumal we get

R = 8 / 500mA
R = 8 / .0005 = 16000

So the resistor you need is a 16000 ohms or 16Kohms.

Now to expand on this cct if we want to add another LED we can do it either in series or in parrallel.

The difference between a series and parrellel cct is that in series they are linked one AFTER another and in Parrallel they are linked one BESIDE another.

Series circuits will have a voltage drop per LED, a parrallel cct will share the same voltage drop.

A series circuit will have the +ve side of a LED feeding the -ve side of the next LED (one AFTER another) if one LED fails the whole cct is broken

A parrallel cct will have the -ve & +ve sides feed from the same point. (one BESIDE the other) if one LED failes the rest keep working

Series cct with 2 LEDS

Voltage for LEDS 4V X 2 = 8 votage for droping resistor = 12 - 8 = 4

R = 4 / 500mA
R = 4 / .0005 = 8000

Series cct with 3 LEDS

Voltage for LEDS 4V X 3 = 12 votage for droping resistor = 12 - 12 = 0

R = 0 / 500mA
R = 0 / .0005 = 0

So you could run 3 LEDs without any resistors

For the Parrallel LEDs cct

You will still need a droping resistor and only the Max current has changed

So for V we need 12 - 4 = 8.

We know the max amps is now 500 milliamps * 2 = 1000 mA

R = 8 / 1000mA
R = 8 / .001 = 8000

Note that the car voltage is a nominal 12 volts and could go up to 14.7 V so this would need to be accounted for.

In the situation where you run all LEDs and no resister an extra lead could be added to allow for the 14.7 volts and protect the LEDs from over voltage.

This is a basic description and more things will need to be taken into consideration but this gives a general outline of how it works.

Warren
     

[kimbosound]

That will be $85.00 thanks