LED Trailer Lights

[johnday]

Guys, I've been trying to follow all this, but my brain isn't letting me. /forums/images/graemlins/confused.gif Can't you just adapt the pigtails to the existing wiring and plug the lights in? I've been wanting these lights myself on my trailers. Brighter is safer. /forums/images/graemlins/grin.gif

 

[HammerFour]

If you have the standard rubber mount round lights ( 4" or so ) , the plugs are the same for the LED lights. For the others, I dunno.

 

[johnday]

tw; Thanks for the reply. All my trailers have the oval tail lights but I'd think I could do what ever is needed to adapt the pigtails. I'm wondering if there is some sort of resistor that should be in the circuit too. All that techinical stuff being thrown around has kind of confused me. /forums/images/graemlins/confused.gif /forums/images/graemlins/grin.gif

 

[frederic]

Series resistors are an unnecessary addition, if you do the schematic like I have on my web page.

The voltage regulator, operating as a current regulator, handles all the necessary current limiting for all the strings.

With this design, you're cutting down your parts count quite a bit, and risking burning out LED's by about 0.5%. Certainly nothing to worry about.

I have that exact design in my truck's taillights and it works fine. Beats replacing bulbs every 6 months. See, my oversized alternator likes to "drift".

Due to ohms lawn, current resistors in series with LED's require the voltage to be known. Alternators *should* be 13.5V all the time, however we know a lot of factors influence that value. Turn on the AC and the lights, have a weak battery, moisture in the regulator, poor battery connections, etc, can easily cause the voltage to fluctuate slightly. The biggest factor in voltage is RPM. How often do we run our vehicles at a constant RPM? Never! We brake, accelerate, etc.

Minor fluctuations in voltage yes, but they are there non the less.

If you really, really want to run each LED in parallel, using one current liminting resistor per LED, calculate things using 14V just to be safe. That gives you 1.5K resistors, I think, instead of 1K or 1.2K.

 

[johnday]

frederic; Well, I solved my problem with the LED tail lights. I went down to my local T/A truckstop to see what they had. Low and behold, the bloody mess of electronics is enclosed in the unit. The cutest little circuit board you could lay eyes on. Just have to splice the pigtails. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[frederic]

That does make it easier ;-)

 

[johnday]

Gary; Thought I owed you one for kinda hijacking your thread. /forums/images/graemlins/blush.gif I got some RoadPro brand, 62 LED modules at my local Pilot Truckstop, not T/A like I posted earlier. I also got the pigtails extra. Turned out that my original lights already had compatible connectors, so the pigtails are going back. The modules ran me $30 apiece. I like them, can't wait for night so I can light up a soccer Mom tailgating me!! /forums/images/graemlins/shocked.gif /forums/images/graemlins/grin.gif This photo is one of the connectors.

 

[johnday]

This one is of the LED module connected.

 

[johnday]

This is with the brakes on with the old lights.

 

[johnday]

This is with the LED module with the brakes on. Quite a bit of difference.

BTW, what do you use to cut the oval hole in the steel, plasma cutter?

Trucklight has a real nice website with LED modules, along with DOT lighting regs for different configurations. Worth a look. /forums/images/graemlins/grin.gif

 

[GaryBDavis]

Oooh, a plasma cutter...

I've put in the 220V/50A outlet for the day when I do finally buy one, but until then, I cut the two end holes with a hole saw. If the piece I'm working on is small enough, I do it on the mill and then use an end mill to cut out between them. If it's too large, I cut the end holes with a drill and jig saw the middle out. From there, I hand file it a bit and smooth over the sharp edges with a round stone chucked up in my drill. I can't stand to see one cut out by hand with a torch.

I'm going to have to get me a plasma cutter one of these days...

 

[frederic]

For a decade I kept putting off purchasing a plasma cutter, and early last summer I purchased one. A Miller 375 actually, rated to cleanly cut 1/2" plate.

And it cuts 1/2" plate like butter, it's amazing. I still will often cut straight pieces with a variety of other cutting tools, but for anything curved, angled, etc, the plasma cutter is an amazing machine. It was worth every penny.

And, it fits perfectly on the moving dolly next to my Lincoln 170T Mig welder /forums/images/graemlins/smile.gif

 

[johnday]

Gary; I used a plasma cutter a few times, unfortunately, it's not mine. Using the hole saws works pretty good, but instead of a jig/sabre saw, I've used a cutoff disc in a Metabo to cut out the metal inbetween. Just got into this welding stuff within the last year. I don't do alot at home, but the weldors at work let me burn some when it's not a certified weld. One of these days I'll get good enough to please myself. I really like that 7018 rod! /forums/images/graemlins/grin.gif