Hi,

I'm interested in creating le mans modern protoypes, including lights, like the real thing. I' m working on a panoz and a 99 bmw for now.

But I'm a little lost to choose the correct LED references, wiring, etc...

I searched on the forum some tutorial, but didn't find anything. :confused:

For example, I'm wondering about the wiring : will the 14 volt 8amp of my track power supply will burn my LED assembly (2 lights on front, 1 or 2 light in rear) ? odes it need some elctronical components to avoid this ?


how do I do the wiring ? do I sold the LEDs in serial or parallel wiring ?

etc, etc...

Thank you for your help !

Hi Dimitri,

you need resistors to protect the LEDs!!
If there is enough space (not in LMPs i suppose)
you can buffer the power with a special capacitor.

I will send you a diagram. Give me a bit time.

Regards

Ebi

Thank you a lot ! I was naively thinking that I just have to sold the led on the motor posts ^^

BTW,

is there any possibility of mounting a permanent light on a h0 car ? I mean, a light that always work, even if the car is not running (= when Im' not pushing the trigger of my controler) ?

is there any possibility of mounting a permanent light on a h0 car ? I mean, a light that always work, even if the car is not running (= when Im' not pushing the trigger of my controler) ?

Yes, as i wrote you can store power in a little capacitor.
I will show you the thread in the german forum... :wave:

But imagine, you'll need space in the body.
A VW bus is perfect... :)

Salut

Ebi

thanks ;)

stupid i am...

Did you see the "Playing with LEDs 101" thread??? :o

No...Stupid I AM MYSELF ! ^^

I just clicked the last page, saw some custom cars projects...didn't think to read the first pages of the topic.

Shame on me ! bouhhh !!! bouhh !!!!! (french crowd sound of shame).


edit : already 6 pages readed...and I'm not sure of what I have to do ! lol

Yes on both counts D!! You will need a lot of room for a super capacitor, and you really need to be careful with them. They can give you quite the zap if they build up a charge. I stick with the smaller ones just to smooth out the power flow. Resistors are required for LEDs, and depending on how you wire them (parallel or in series) and the color the LED emits will determine the ohms and watts required for the task at hand. White LEDs use more voltage than colored ones. For head lights there are 3 styles of white. Sunshine is a nice yellowish hue, Warm is not as yellow, but not the bluish of the newer halogens, and the regular white is very much the effect of the newer high output head lights. There are links on the LED101 thread that will send you to a graphical resistance calculator. What you are trying to shoot for is the lowest wattage resistor for the lights being used. As you go up in wattage, the size of the resistor increases as well.

I pretty much show the whole process on that thread, and improvements as you go along. I've found as I went along some of the LEDs were finicky, and required a rectifier diode to keep them from dying on me. I have also found the 1.8mm LEDs to be on the fragile side, and care must be used when bending the cathode and annode (the legs of the LED. I've ripped more than my share of them right off the LED. I'm available via PM for any questions you might have or you can ask here if you want. I pop in all the time.. Joe

Thank you, Joe. Now some things are more clear.

Tonight, I'll read again the led101 thread (at least the beginning ^^ ) and try to come back with more precise questions ;)


thanks

dimitri

Go for it D!

http://i44.photobucket.com/albums/f30/modelmurdering/DSC04814-1.jpg

http://i44.photobucket.com/albums/f30/modelmurdering/DSC04812-1.jpg

It's well worth the effort to try it.

http://i417.photobucket.com/albums/pp251/slotcarman12078/a0f0e94e.jpg

http://i417.photobucket.com/albums/pp251/slotcarman12078/b0ef81d5.jpg

http://i417.photobucket.com/albums/pp251/slotcarman12078/939651a3.jpg

http://i417.photobucket.com/albums/pp251/slotcarman12078/edff7431.jpg

Every car is different, and the LEDs used varies from model to model. I believe there is a link to the guy I buy all my LEDs from on the first couple pages in the 101 thread. He sells on Ebay. Just so you know, the 1.6mm is really small. They are the ones used for the lead sled tail lights. They are measured by the size of the little dome part. The 2.0mm version is measured at the light shaft. The 3.0mm is measured at the diameter of the whole LED. Larger headlights will be best fit by the 3.0. The cobra and sled both use 3.0, and had to be sanded down a little, as well as sanded to flatten the dome. I use a grinder bit on a dremel to accomplish this. (Watch the fingers!!) I usually paint the LEDs silver to stop the unwanted glow inside the hood, and mount them in place with JB Weld. Rough surfaces from sanding can be smoothed back out with a skim coat of brush on super glue.

Looking at the pictures you can see the difference between proper shielding of the headlights (the cobra) and improper (the sled). don't know how I missed that!! Oooops!!

Yes, it's definitly cool. My own goal is a little diferent : I want to make endurance cars (le mans 24h, daytona 24h, sebring 12h, etc...) with real lights, so I'll have no need for particular shapes of leds (because it will be under a "glass bulb", don't know the name in english) but the base is the same. ;)


So...I readed the 7 first pages of the topic. Quite tuff work, since the content is very large, and the language used is not my usual one. I guess I understand how to do now, but I have two questions I did'nt found an answer :

-I beleive you make your wiring in serial for the rear 2 lights, serial for the front 2 lights, and then wiring the whole thing in parallel ? Am I correct ?

- the only think I still not understand is about capacitors (to make the lightning permanent for a few seconds). I didn't find any precise info on that (what type of component we need, how to wire it, etc...)

BTW, One thing really cool I saw in your topic, is the crossroad railway lights ! flashing when a train is coming. So cool ! When I'll finish my racing tracks (h0 and 1/32), I believe I'll go on model railroad, but certainly a smaller scale (because I don't have much room left...). All that cool stuff (lighted building, automatic events, etc...) I like it very much.


thanks you !

Awesome looking cars, SCMan!

errr... It's living at my house now. Have no idea how it works... but it does and I'm really diggin that fact. The technical stuff is lost on me, but the idea is a good one, so go for it Demether. MUCH better than a Flamethrower or as some call them "Lamethrowers". :thumbsup::thumbsup: nd

D,
Are you gonna light up the numbers on the sides of the cars too?
I saw that this year and thought it was neat as heck!
There's gotta be a way.

Rich

I have experimented with different methods of lighting them. The majority are wired with the head lights in series with their own resistor, and the tail lights the same. Because of the different demands of the white LEDs verses the red LEDs, they have to be wired seperately past the rectifier diode. Each circuit has it's own resistor. I have attempted using one resistor with 4 similar white LEDs wired in series with good results. The tail light LEDs can be painted red with a candy/transparent paint, or can feed red fiber optic cable. I tested the set up on a chassis, but never got to the installation part.

As far as the capacitor, any ceramic disc capacitor will work. I have found the small ones do a decent enough job of smoothing out the light. Tomorrow I'll set aside some time to put together a bunch of links to help sort out all the nuts and bolts..

Make sure the voltage of the capacitor is rated higher than the voltage being fed. I used 50 V caps just to make sure there is a safety cushion!!!

Cool ! thanks you ! Does we absolutly need a rectifier diode ? any diode will work (I've got some) ? If I understand what I read, it 's used because when you release the trigger of your controller, the juice goes reverse ? Am I right ?



Are you gonna light up the numbers on the sides of the cars too?
I saw that this year and thought it was neat as heck!


I think it's a great idea, but if we do that electronicaly, it will take too much space under the body. A solution could be to use some fluorecent light to make the rear of the decals numbers, found in a creative hobby store, perhaps ?

I did find a link for self adhesive glow in the dark inkjet film, but you would need to cut the meatballs out by hand. A black light will keep them glowing as long as it's lit.. http://www.hyaz.com/glow%20dark%20inkjet%20new%20film.htm

The rectifier diode is not an absolute requirement, but it (supposedly) helps preserve the LEDs. The first bunch I made don't have one. All it does is act like a check valve to prevent the current from flowing in the wrong direction. The moter when coasting/braking produces a small amount of current in the opposite direction. Whether or not it's an amount capable of harming the LEDs is unlikely. However, a spin out where the car does a 180 degree running backwards situation could happen (It has here) and the reverse current is more likely to cause some damage. When I did all the LED Sleds (12 of them) I ended up with a pile of dead LEDs. All but one of the fatalities were white ones. I'm not sure if the LEDs themselves were to blame, or it was something else. The white ones are much more expensive than the colored ones, and it caused of quite a bit of frustration having to do the same cars over and over.. :freak: not to mention the expense of replacing all the duds. :cry:

thank you.

do you think that reverse phenomenon happens on a track where third wire brake is not wired ?

Correct me if I'm wrong, but a diode "eats" 1.2volt (I used a diodes bridge to make a cheap variable powersupply on my old track). Do you include this consumtion in your resistor calculation ?

the diode si installed simply in serial, on the pickup shoe (or where you wire the light kit), before the light kit ?


thank you (as I said, I ask a lot of things, I hope it's ok ^^ )

Ok. Here are a few links to help you along with your project..

http://www.quickar.com/noqbestledcalc.htm
All the planning needs to be done first. Which LEDs will be used, are they all the same voltage demand, etc. Using the same olor LEDs will make things a lot easier, as the size of the resistor is smaller with 4 LEDs in series. You can get away with a 1/4 watt or smaller resistor doing it this way. 14 volts seems a bit low. Is that all these will be run on?? If this is the case, you may need to split the LEDs anyway as there is barely enough power to drive 4 in series.

If you want to attempt 4 white LEDS in series...
With a guess of 15 V with 4 white LEDs using 3.5V there is barely enough power to drive the LEDs. The resistor called for would be 56 ohms. Under these circumstances a rectifier diode would be needed as the resistor would not protect the LEDs in case of a spin out, or an accidental power reversal.That drops the voltage to 14. There will be power issues, it might be worth a try, but the results will most likely be disappointing.

If you're going to split it into 2 series...
If the rectifier diode drops 1.2V, you can deduct that from the power source. This can be tapped right from the chassis under the magnets. The left pick up (american driver's side) is the hot. From the rect. diode solder 2 resistors. 1/4 watt 330 ohm for a pair of white LEDs, 1/4 watt 680 ohm for the red tail lights. These resistors are very small and with the rect. diode (1N4001) will all fit rather well in the cavity ahead of the motor. Care must be taken to assure there is no shorting. To make life easy I use very small gauge wire 28 stranded. Always look at everything before drilling any holes!! Also, it might be worth the time to test the assembly on the chassis to make sure it all works. The resistor calculator is a starting point. You may need to raise or lower the value of the resistor. What you are looking for is the sweet spot. The point where the LEDs will light with the slightest pull of the trigger. The beauty of a proper set up is the LEDs will stay consistant through the full sweep of the controller. It can be hard to get it exactly right.. especially the first few times. I've popped more than a few LEDs in the process. :)

Cristal clear answer ! thank you a lot ! I beleive I have to try it myself, now !


thanks again ;) I'll post the results here soon !