LED Upgrade to Rear Rectangular Lights

patrickt · #1 (**permalink**) 08-18-2010, 01:50 PM

Ron's third brake light got me to thinking.... I have an extra license plate light fixture around here somewhere, I may just try drilling six holes through the front of it and then mounting six clear LEDs, in series, through those holes. Those LEDs would be RED and the superbright type. With a source voltage of 14.6v, and each diode having a diode forward voltage of 2.2v and a forward current of 20mA, an 80 ohm resistor would be all I needed and just feed it directly off the brake light switch. It would be hardly noticable when not lit, and would look something like this when you were on your brakes (although obviously much brighter):

RodKnock · #2 (**permalink**) 08-18-2010, 03:17 PM

Quote:

Originally Posted by patrickt

Ron's third brake light got me to thinking.... I have an extra license plate light fixture around here somewhere, I may just try drilling six holes through the front of it and then mounting six clear LEDs, in series, through those holes. Those LEDs would be RED and the superbright type. With a source voltage of 14.6v, and each diode having a diode forward voltage of 2.2v and a forward current of 20mA, an 80 ohm resistor would be all I needed and just feed it directly off the brake light switch. It would be hardly noticable when not lit, and would look something like this when you were on your brakes (although obviously much brighter):

Yep, that outta look good. Your next project should be side marker lights and turn signal indicators in the side view mirrors to match your Cadillac Escalade.

patrickt · #3 (**permalink**) 08-18-2010, 03:22 PM

Quote:

Originally Posted by RodKnock

Yep, that outta look good. Your next project should be side marker lights and turn signal indicators in the side view mirrors to match your Cadillac Escalade.

Now don't make fun....

If properly done they would be virtually undetectable except when you were on your brakes. I might give it a shot over the winter. Although something like that requires a deft touch, so it will probably end up in the trash.

patrickt · #4 (**permalink**) 08-20-2010, 09:03 AM

OK, look at this. The size of the 5mm LEDs with either the clear or red plastic cover over them is almost exactly the size of those little white punchouts for three ring paper. Now imagine that they are either red, or clear, as per the lens pic below. Now seriously, what do you think?

This would be even better. These 5mm High Flux Piranha LEDs have a clear bulb that only peek out 2mm.

RodKnock · #5 (**permalink**) 08-26-2010, 02:30 PM

Quote:

Originally Posted by patrickt

OK, look at this. The size of the 5mm LEDs with either the clear or red plastic cover over them is almost exactly the size of those little white punchouts for three ring paper. Now imagine that they are either red, or clear, as per the lens pic below. Now seriously, what do you think?

This would be even better. These 5mm High Flux Piranha LEDs have a clear bulb that only peek out 2mm.

Any news on the discotheque?

patrickt · #6 (**permalink**) 08-26-2010, 03:06 PM

Quote:

Originally Posted by RodKnock

Any news on the discotheque?

As a matter of fact, "Yes."

I ordered a half dozen of both the 3mm and 5mm super bright LEDs and they have arrived. The 5mm lights are very bright; maybe too bright. I'm serious. So I'm first going to experiment with the 3mm ones. I need to glue them in to an array, solder the backs, and then I'll review how bright it appears. I might get that done tonight. If the array of 3mm LEDs looks right, then I'll drill the holes in the back of the light fixture.

patrickt · #7 (**permalink**) 08-26-2010, 04:43 PM

OK, here's a picture of what the LEDs look like. The little round bulb is only 3mm in diameter and has a height of only 1mm. It will barely stick past the chrome hole in the license plate light.

Here are six of them superglued together. The back has the little prongs soldered together.

And here are some pics. I think it's definitely bright enough. Tomorrow I'll take a crack at drilling the six 3mm holes in the license plate light and mounting it in there. If it looks good, I'll keep going. There's a little plastic liner inside the light that will require some fabbing, and I'll need to add a little resistor as well. I'll only tackle that if the six little LEDs look pretty much invisible in the light itself. Here are some shots of them lit. It's pretty tough to take a picture of a lit LED, so no complaining.