Hey guys,
well im in the middle of making LED tail lights and im looking for some kind of dual brightness LED. OR at least a way to have one set of LEDs be somewhat bright and another much brighter once the brake is applied.
I have a 06 accord and the tails of those are LEDs. Those LEDs are dual brightness and would work great. Anyone know of a place or the “proper” name for a dual bright LED? Ive been looking around the web and I gots nothing.
thanks guys
once I have some LEDs I might need some insight on wiring them up.
almost any LED can vary in brightness depending on amperage.
Most of the aftermarket bulbs from superbrightleds.com just run two stages. so basically half the leds are on when just illuminating at night and the other half turn on when the brake is applied.
It’s a real easy circuit. What you need to do is put 1 higher ohm resistor as a feed from the tail lights, and 1 lower or identical ohm resistor from the brakes. You need a diode before each resistor to prevent back-feeding though.
The above will work if you want to use the same LEDs for both functions, You could do it simpler by running seperate strings.
If this doesn’t make sense and no one else chips in with a way that makes sense, send me an email and I’ll write up a word document with all the details.
Just use the existing wiring. The OEM harness has an extra input from the brake switch. Wire in a seperate string of LEDs at a higher current.
String 1: Parking Lights ON = LEDs at say .010 Amps. (~1.5K resistor)
String 2: Brake Switch ON = LEDs at say .030 Amps. (~1K or 500ohm resistor, we would have to test it)
Rugsr - you’ve got the 2 guys with the most LED knowledge on your topic… between either one of us we can come up with a solution for you. (We used to work together at a place that specializes in LED lighting for Aircraft, what you’re asking for is super simple to do. Luke still works there, I’ve since moved on to bigger/better things).
Did this on my lunch
Heres my two options for the S2000
Still using the classic AP1 tail light look but replacing bulbs with LEDs.
Currently the tail lights are apart after 300degrees for 10 min in the oven.
I tried using LEDs behind the stock red and white lenses and I dont think it will work. The lenses have those little reflector diamonds in there and the LEDs lose their intensity etc
So im in the middle of making my own lenses currently.
Option 1 shows the running lightsin all 4 circles and when the brakes are applied the inner of the outside circles light up. The turns and the reverse can be seen on the inner circles.
I like Option 1 because the S will have 4 circles always on, reminding me of the GTR’s (i likes)
Option 2 is a little different but is more traditional when it comes to AP1 tails. Brakes on the outside, turns and reverse on the inside.
Separate Brake lights are easy. What you need to do is find out what the Forward Voltage Drop is for the LEDs you are using is. Then make your LED strings such that the total of all the VDs is less than 12V (idealy somewhere around 8 such that you can use reasonable resistors). Then calculate the resistor needed by 12V - (Sum Forward Voltages) / Desired Current (Probably 0.020A or 20mA, but figure this out from the Datasheet of the LEDs) = Resistance needed. You’re going to need a bunch of different resistors depending on the # of LEDs in the string and the different colors having different forward voltage drops.
You can use a common ground for all these; and then just power them off the separate existing feeds from the car.
If you want some help with what resistors you’re using, email myself or Lucas the Datasheets and we can easially come up with what you need.
---------- Post added at 01:00 PM ---------- Previous post was at 12:59 PM ----------
SMD = Surface Mount Device
Basically instead of having leads that go through a circuit board, they just solder to the surface like a microchip does.
If you’re using the same string of LEDs to do both brightness levels then yes. The Marker Lights may back-feed into the Brake Light circuit if you don’t.
As a plumbing example… Y fitting… 2 inlets, 1 outlet. If the you want to keep water from flowing from 1 inlet back up the other inlet you need to block it somehow. That’s what the initial diodes do. Prevent the marker lights from powering the rest of the brake lights on the car, and vise-versa.
[QUOTE=97FormulaWS-6;2348372]Separate Brake lights are easy. What you need to do is find out what the Forward Voltage Drop is for the LEDs you are using is. Then make your LED strings such that the total of all the VDs is less than 12V (idealy somewhere around 8 such that you can use reasonable resistors). Then calculate the resistor needed by 12V - (Sum Forward Voltages) / Desired Current (Probably 0.020A or 20mA, but figure this out from the Datasheet of the LEDs) = Resistance needed. You’re going to need a bunch of different resistors depending on the # of LEDs in the string and the different colors having different forward voltage drops.
You can use a common ground for all these; and then just power them off the separate existing feeds from the car.
If you want some help with what resistors you’re using, email myself or Lucas the Datasheets and we can easially come up with what you need.[COLOR=“Silver”]
Oh man my brain just thru up reading that lol
I think I get what your saying. Ill have to sit down and get some #s to ya.
Maybe even some more pics
Each LED has a “rating” called forward voltage. Lets use a forward voltage of 3.2 volts as an example. Meaning you need to over come 3.2 volts to light the LEDs. In a 12 volt system you cannot power 4 LEDs in series, or string, as:
3.2v x 4 = 12.8v (Which is greater than the Car’s 12 volt system)
But you can use 3 LEDs:
3.2v x 3 = 9.6v
With the total required forward voltage of 9.6v you still need to meet the source voltage of 12v, 12v - 9.6v = 2.4v
If you know what brightness you want to achieve through testing you can set your resistor. If not, start at the nominal and go from there.
Typically LEDs range from .015A to .030A at normal operation. Using Ohms Law (Voltage = Curret x Resistance) we find that:
2.4v = .015 x Resistance
Resistance = 160 Ohm
This tells us you can use 3 LEDs in one string in series with a 160 Ohm resistor. A protection diode will need to be used, as Mike mentioned, which will only add to the voltage side as you need to overcome another forward voltage.
But, that is how you do it.
EDIT: Which LEDs are you using? Manufacturer and their P/N?
OH MAN! I get it!
I need to go back to NCCC and take electronics again. Ill pass now =)
Thanks Luke
Still at work but once I get home ill post up details
ok so heres some pics and updates
the LEDs I currently have are 10mm white LEDs with built in resistors. I bought them off ebay for a project yrs ago and figured i would use them again. Built in resistor = less work for me.
BUT if you think if wont work as well as something else let me know.
Heres the LED behind the OEM lense. as you can see its not that crisp and cuts down on the brightness
Heres two pics with the same LED behind the red lense. The LED is brighter in the middle and dimmer around the edges. So dim id be afraid to use them as normal brake lights in fear that people would have a hard time seeing me. I almost wonder if I should use a 5mm LED for more of a direct look?
Check out the stock AP2 tails lights. They almost look like they have 10mm but theirs are pretty bright
Im in the process of making my own lenses if I cant get the OEM ones to work out
I un-plugged some bulbs in the tail and touched the LED to the turn signal socket just to see how they would look. I wanted to hook it up to the brake light but I had no one to push the brake pedal
Im still up in the air on what or which LEDs to use
Heres a vid
In the vid the LED doesnt look crisp at all, but its also because the LED is farther away from the lense then normal.
If you choose to run all the LEDs in parrallel then you can use them as is. But, you can decrease your power comsumption, not that it would draw much to begin with, by re-arranging the circuit. It is up to you.
You actually want the lens to cut down the light output. This makes the light easier to see other than from straight on. I would try to cut it down even more.
I would test a few of your ideas to make sure you get the right brightness before you start switching LEDs.
