Driver for car dome/trunk lighting

I have ordered two of these: http://www.fasttech.com/product/1103509 - same as what's used in the outdoor floodlights, I believe? Anyway, wanting to cobble together dome and trunk lights for the car. I have a few of these things...

...12v AC/DC capable, originally used with a 3-up XR-E module with LEDs in series (as it'll never be used with 12V AC I have removed the rectifier diodes). Will these drivers run those 10W arrays, or is there something better? I have no idea what the output current on the drivers is, but I'm assuming the 'R150' is a sense resistor and that lower resistance there will give more current. Any advice/recommendations/recipe for a better DIY driver?

I’ve driven 10W arrays with them. You have to have the ones designed for 3x3W emitters. Removing the rectifiers is a must in order to work properly in a car. The worst-case voltage with dropout is right on the edge.
I didn’t tweak the sense resistor on any of mine, but I suppose you could if you wanted to.
Edit: I assume by 10W emitter arrays, you mean the small 3 by 3 ones and not the larger 1x10 ones. This driver will only drive the 3 by 3 ones.

10W 950LM 6500K White LED Emitter 1000mA / 10~12V

Yup, that should work. Check the emitter current, and adjust using the resistor. Also keep a close eye on the driver temperature, as they tend to get a wee bit toasty even at the 8-9W I was using them for.

It's got a dedicated 'DIM' input! On the chip, anyway, probably no pad on the little board for it though.

http://www.micro-bridge.com/data/CRpowtech/PT4115E.pdf

comfychair: I’d really love to see how/what/where the project you’re doing for car use. May be interested in doing something myself. Maybe another sub-forum, automotive LED? I just replaced all the bulbs on the interior of one of my cars. Sure is alot better with LED :bigsmile:

Been there, used these drivers in lots of places. Added dimming pot… read the first thread:

Yeah my main reason for doing it is that I don't drive the car all that often, and for some unknown reason sometimes the trunk light doesn't turn off even though the trunk's fully closed and latched (the 'trunk ajar' indicator even turns off, but the light stays on - and they both use the same switch on the latch!). Replaced the switch, fiddled with adding some material to the switch lever, didn't help, and there's no adjustment possible at either the hinges or the switch/latch/striker plate. Still maybe once a year, I get in the car and... dead battery AAAARGH!

Plus, the trunk light is awfully dim. Dome light is acceptable but could be better.

Is there a cheap & easy way to add a 30-60 minute timer to shut them off if (when) the switch goes wonky again?

I want a brighter light for the hatchback area of my car, and the stock bulb is supposed to be a 6418. Is there anything I can buy that just plugs right in?

http://www.ebay.com/sch/i.html?_sacat=0&_nkw=6418+led&_frs=1

10W is going to be a huge amount of light, are you sure you really need that much? I’ve modded both the dome lights in my wagon and 2x XR-Es at what I guess is ~350mA using a similar driver to yours and it’s a ton of light, sometimes even too much at the front. Even the outward facing LED on the rear dome light (did that so I could see my mtb at the end of night rides) pleasantly illuminates 10-12ft back from my car.

Still, they are a huge improvement compared to my friends’ cars :slight_smile:

As for the time problem, do you have a soft dim/ auto off function for the main dome light? If not I’m sure there’s some kind of off the shelf 12V timer, it’s just a case of finding it. Or you could build your own:
http://www.mp3car.com/hardware-development/62668-dome-light-dimmer-with-delay.html

there seem to be plenty of ideas out there if you search “dome light timer”.

Too much light is about perfect, I can't believe anybody here would even ask that! For the trunk, at least. I'm sick of the less-than-candlelight output back there. The dome light might be a different matter, I'll worry about that when I get there.

Car is a '95 Civic EX, so no fancy built-in timers or dimmers which makes the LED thing easier. Thanks for that mp3car link... I found a couple ready to use units on ebay - DEI-528T or DEI-611T are pretty cheap and look like either will do the delay function but I'll have to track down the .pdfs and see if one's better suited than the other.

It’s for the trunk part of the hatchback in a 2005 Elantra. The stock light is pretty dim, it’s about as bright as the light in the glove compartment. Naturally, I want more light and figured LED was the way to go.

Yes... I posted an ebay search link for you a few posts up the page. Tons and tons and tons of LED retrofit bulbs in that format, something like 2700 hits if I recall.

I know, I know, I felt a bit odd even writing that :slight_smile: I think that you’d be surprised at how much light even 2-3W of decent LED power can produce in a small space - for a trunk light it may even be worth using 2 or 3 lower power LEDs in series spaced around the trunk, so that when you have something bulky in there (gagged Mafia stooge for example) the light doesn’t get blocked. Even adding a light to the trunk lid to light up the area behind your car might be an option too, I know that I like that on mine.

here’s the build thread for my front dome light

If you want any pics of the rear one, just let me know.

Looking forward to seeing what you get up to and how you fix the timer issue :slight_smile:

I can't tell you how happy I am to see somebody else's workbench looking as beat up and abused as mine, I thought I was the only one.

thanks :smiley: It gets a lot of use and no matter how many times I tidy it, it always looks like that!

This thing: http://www.ebay.com/itm/320887401763 does it all, but at that price it damn well better.

it’s also designed for ground side switching whereas most “modern” cars switch the supply side.

http://www.ebay.com/itm/320887402868