Making a LED Brake light [SF-convert instrument panel...]

Im thinking about doing up a tail light for the er5.

something that follows the line of the tail, instead of sitting there apparently oblivious to the fact that the rest of the bike isnt flat

but we will see how that pans out in time.

 

Re: [HOW TO]convert instrument panel backlight to any colour LED

Responded elsewhere to question, but sticking answer here in case it helps anyone else. Plus, Im sure other people have different thoughts.. my suggestion was just one way using brighter than standard LED's that I threw together just now with no thought..

so theres no doubt better ways.

Of course, you could do this whole thing using 5Mm and 10Mm Clear Red or White LED's and just use resistors and not the LM317's.... but it wouldn't be half as cool and advanced

Also - the cheap 'bulb replacement' ones are shite.. they also break (full of dry joints... :glare: ) if you go anywhere less than 'smooth' or have hardish suspension...

If you have clear lenses, then get red StarLEDS.. if its red, just get white.

Now, simply get some BreadBoard (prototype board) to use as a sturdy 'holder'.
Determine a suitable pattern to match the lens. Most stuff works on V shapes with a central | that lights up with brakes.. or "inner-outer" rings. You dont need nearly as many for brakes on as you do parkers... and the parkers are always duller through either lower output LED's or through running high-resistance resistors.

Cut breadboard to suit and fit inside the current housing somehow.. dremel's are your friend.
Cutout the mount holes iwth a drill bit for the Star LEDS. You may or may not want Collimator lenses.. it really depends on what effect you want and how bright you want it.

*Easiest* way to achieve a "Parking" brake effect is to run say 2 or 3 LED's if its a 'double-ring' tail lights, or say 4 if its a single 'wrapround' type (can't be assed looking).
Use an LM317 and run the 4 Stars in series, with a high-current limiting resistor to dull them. Or run simply 1 Watt stars for 'those' ones.
Use another LM317 with a lower current limiting resistor to make them 'normal' brightness - and use say 3 or 5W star leds.

This works well beacuse your brake light will ahve a common ground and a postive for 'parkers' and a postive for "brakes"...

I would suggest then mounting a heatsink on the rear of the breadboard that is electrically isolated but mounted to the back of the star leds. mount the LM317's to the other side of it, or to a seperate heatsink. You should also try keep them sorta weather proof - so wrapped up in heatshrink or stuck in a sciliastic sealed jiffy box.

If you want to get proper advanced - you can play with running a small relay and another LM317T that supplies the 'difference' to the "low-watt/parker" star leds... really just need a relay, LM317T and a resistor for the difference between whatever you run them at and what their 'normal' current is.

Resistor wise - use 5% Ceramic ones - cope better with the heat... to calculate, use the supplied details, you can also find lots of info about LM317's on the internet in use with StarLED's.

The same principles apply to the 'knock-off' Luxeons - available at Jaycar slightly cheaper - and probably just as suitable fo ryour application.

From memory, 1-3W luxeons in white or red run about 490ma forward current (2.95v) and the 5W's are around 700ma.. meaning you should run the LM317s bigger brother that does 4amp instead of the LM317's 1.5amp limit...

what you want to do is fairly straight forward - its more deciding what pattern you want, how you want to stage Parkers vs Brakes etc.