Lets talk about LED's and powering them

[Seanz0rz]

im familiar with the lm317, last year i built a variable voltage power supply in my electronics class. its actually what im using to test alot of these circuits.

i know the voltage in the vehicles will vary from something like 11 to a max of 14.5. the low end doesnt matter to me, because it wont hurt. but the spike could. i am ultimately designing these to be durable. i think i will experiment with the resistor and see if it performs like i want.

thanks for your help guys.

[4x4mike]

ledsuppy.com has the drivers I got for my other projects. They are good drivers but expensive. The newer ones I've tried are the buck toot's at 350ma for my red cree dome light.

[MTL_4runner]

thanks guys. looks like i have all the tools necessary.

next is just ordering parts and waiting patiently for them to get here.

here is a question for you. how should i design the brake/park lights?

should i have say 5 lights for the parking light, and all 15 hooked to the brakes?or should i do some kind of dimmer thing, where all 15 are illuminated but at half brightness with parking lights, and then brake lights fully illuminate the LED's. how would i do either?

What about something like these instead?
http://cgi.ebay.com/ebaymotors/1996-...Q5fAccessories

[Seanz0rz]

ledsuppy.com has the drivers I got for my other projects. They are good drivers but expensive. The newer ones I've tried are the buck toot's at 350ma for my red cree dome light.

what on god's green earth is a "buck toot's"?!?!?!?!

What about something like these instead?
http://cgi.ebay.com/ebaymotors/1996-...Q5fAccessories

Jamie, i have considered those, and i might buy a set to see how they are.

however, this led project isnt so much for the 4runner than it is for the vw. i have been wanting to put LED arrays in the 4runner for years, but the vw is a more pressing issue as i want to keep the power consumption as low as possible (35A is what i have to work with on that vehicle)

i purchased the 30 LED drop in lights, they are absolutely terrible, i am so disappointed i spent so much money on so much crap. and i have exceeded the return period as well. they will get used in other projects somewhere, but basically i burned about 100 bucks on this one. live and learn.

next week ill order some of my parts and all of my LED's. i will prototype it on a breadboard, then solder it all up on a protoboard and test it extensively. then i will likely make some PCB's (either on my own or through a company). from there i might sell them on the VW boards. and i will likely make a set for the 4runner as well, and see what the interest is in those (probably much lower than the VW crowd)

[Robinhood4x4]

buck toot

http://ledsupply.com/bucktoot.php

[Seanz0rz]

ahhhh ok. i thought it was something like "the bee's knees"

yikes! 10 dollars each! that would be 60 bucks just in vRegs alone.

[Robinhood4x4]

Aaaahhh great!! Now you guys have me looking at LED websites again. I need to make some backup lights, general area lights and a mtn bike light. Bastards.

[troyboy162]

haha im looking back into making a light too. three cree xm-l leds and a dirty current regulator...any way i cut it, its not price effecient after i figure in my time vs those nice kragen hids

[4x4mike]

ahhhh ok. i thought it was something like "the bee's knees"

yikes! 10 dollars each! that would be 60 bucks just in vRegs alone.

Yep I have $50 dome lights (each), 4 total between 2 cars. $100 rock lights, underhood light, etc as the list goes on. They are much better than anything drop in, they are efficient and custom which fits the bill perfectly.

[paddlenbike]

I am constantly disappointed by LED products I find on the market. With incandescent you can just buy something. With LED you have to do your research. Almost all drop-in lights are pure crap...they have the blueish color, have no voltage or current regulation and simply don't last. I pretty much only buy Cree LED products now because they have proven themselves to be high quality and with good CRI. I love everything I have from that company from flashlights to recessed lighting in my home to the circuits I have built for the 4Runner. I went so far as to buy their common stock. I do like Superflux though, and I don't think I will ever buy another 5mm led in my life.

I haven't looked but I don't think they make the bucktoot, luxdrive, etc. drivers in lower drive currents, as in less than 350mA. Because there can be a 25% variance in input voltage between vehicle off and on, I would make an LM317 circuit. Build it right and it will last forever, unlike the chinese led products. My superflux floorlights have been installed for I think three years now and I haven't touched them, ever. And they continue to draw praise from the drunken holiday partygoers I've been driving home lately. You can build a super reliable superflux/lm317 setup for less than many junky drop-in kits cost.

Use the highest voltage for your calcs. The only thing that part of the calculation does is figure a worst-case scenario for heat dissipation, where a 0.5W resistor might be fine at 11.8V you might need a 3/4 or 1 watt resistor at cold-start up when the truck's alternator can be putting out over 15V. My superflux leds are rated at 80-100mA max and I am running them at 62mA. There is no noticeable heat output and the light output and color are great.