Led car conversion help

[Method]

I am trying to convert my rear lights to LED's Red and Orange ones. It is
for a nissan 300zx, what is the best way to make these? I am guessing a heap
of LED's, but what size resistors and regulators should i use? How many
should i hook up in parallel to each regulator?
Would a 12V to 5V regulator work fine? Sorry about the newby questions.

 

[Glen]

On Mon, 11 Aug 2003 08:13:06 GMT, "Method" <pmitsaki@bigpond.net.au>
wrote:

Just buy some 12V LED replacement lamps.

If you want to try it yourself, remember ohm's law. V=I * R
Voltage = amperage * resistance.

I am trying to convert my rear lights to LED's Red and Orange ones. It is
for a nissan 300zx, what is the best way to make these? I am guessing a heap
of LED's, but what size resistors and regulators should i use? How many
should i hook up in parallel to each regulator?
Would a 12V to 5V regulator work fine? Sorry about the newby questions.

 

[Hermann]

You may want to have a look at www.luxeon.com
LED-wise these are _extremely_ bright, and they run on 350 mA max.
current. There should be someone who sells them over there in oz, and
they are better candidates than regular high brightness red or orange
LED's (a notch more expensive as well..)

These emitters are current fed (voltage is more difficult to regulate,
as the emitters need a very narrow voltage range to avoid current
runaway and premature death) so you could use an LM-317 adjustable
voltage regulator and use it as a "current source" (for that, have a
look at the data sheet at www.national.com).

Be careful though, as the emitters take between 300 to 350 mA and if
you connect only one emitter the regulator would have to dissipate
about 5 Watts of heat... (better use a part of the car's thicker sheet
metal as a heatsink).

For the red lights (cruise or brake) you could connect 4 emitters in
series (2 on each side of the car) thereby reducing the wattage that
stays with the regulator (only 1.2 Watts). Bad point: When the engine
is turned off (alternator stops working, voltage drops from 14.7 to
around 12 V) your LED emitters might dim down a bit as the regulator
doesn't get its minimum voltage drop any more (4 x 2.85V typical
forward voltage = 11.4, that leaves only 0.6 V to the regulator but it
needs 1.25 V).
For the orange lights.... use two in series per side.

Do some experimenting. By the way, I'm talking about those Luxeon 1W
emitters (Star Type), not the 5W models! One more thing: these
emitters do need additional cooling surface, so screw them onto a
piece of 3 mm aluminium of a size that you can fit.

If all else fails (or if those Luxeons eat up too many dollars), go to
the nearest cheap auto aftermarket parts store, buy two or four of
those chinese third brake lights (LED version) and rip it apart (comes
with ultra bright LED's and resistors already on a circuit board).

Good luck!

"Method" <pmitsaki@bigpond.net.au> wrote in message news:<meIZa.28034$bo1.858@news-server.bigpond.net.au>...

I am trying to convert my rear lights to LED's Red and Orange ones. It is
for a nissan 300zx, what is the best way to make these? I am guessing a heap
of LED's, but what size resistors and regulators should i use? How many
should i hook up in parallel to each regulator?
Would a 12V to 5V regulator work fine? Sorry about the newby questions.