# LED Application Strip



## T-Man (May 16, 2008)

This is for general information, I came across an LED Light Strip that was run over by a car. The gentleman saved it for me, because he knows my weakness. Anyhow, the strip has 128 LEDs and is used as a portable light for under the hood repair. A few were broken so I investigated. These are 5mm bulbs.

The LEDs are in parrallel, 64 pairs with 32 pairs on a section. Each has a resistor a very small surface mounted resistor. The handle contained a 7.2 Lithium battery. So what is the resistor? Well the resistor is 181 ohms I calculated it at 160. 7.2volt- 4 volts for two leds divided by .02 amps. The volmater told me 185 ohms. I would of used three volts for each LED and used an 80 ohm resistor, so there is a little play in these calculations.


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## tjcruiser (Jan 10, 2010)

I happened to be driving behind a Cadillac tonight and notice that each tail light was made up of two tall columns of LED's, much like your strip above ... all red, in this case.

We did a little cave exploring on our recent vaca, and had some LED helmet lights on our heads ... worked great ... very bright.

LED's are popping up everywhere ... light of the future, perhaps.

Cheers,

TJ


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## Big Ed (Jun 16, 2009)

3 years ago I bought a LED light bar for under the tailgate of my pickup truck.
It mounts in the space under the tailgate and bumper. They are marker lights,blinker and brake lights.
A link of similar lights, http://www.realtruck.com/led_light_bars/R195530CS.html

I got them at a good price off e bay. I was told that if one burns out there is no way to replace it. Is this true T man?

I bought them 3 years ago and when I heard that I bought another light bar so I would have a spare.

3 years now and they are all still lighting. But I have a spare.

Is there a way to replace just one of the lights if one burns out?


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## T-Man (May 16, 2008)

First, the LED is more durable than a bulb. THey can drop and be fine. They last much longer than a bulb too. You can replace them but the secret is using the same LED in brightness. IF it is not the same, it will appear different. If one goes out, it may more likely be a bad connection. Then the hard part is getting at it to replace it. You have to get into the case. So if a few go out, go use your spare and use the first one for parts. That way you will know how to take it apart when your spare gets in trouble. Otherwise use the LEDs for other projects. My opinion is to scrounge anything that has LEDs since they are lasting. Plus it is fun taking thing apart. 

Your light panel is very similiar to what is shown. They are probably rigged for 12 volts in pairs with a small resistor in between.

In my project I didn't bother replacing the broken ones. I think they are a match for my white ones around 10000 mcd. I can't remember the exact number.

One good thing about LED in vehicles is that they will outlast the car. The bar should be fine until moisture gets in. Being on a tailgate it may get roughed up so take care of it.

The most important aspect is making sure the LED is installed in the right direction.


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