Lights for your R/C vehicle.

[LazyDave]

no, no fire and no nasty stuff. An LED works by having a gap between to electrods. The amount ov energy it takes to gump the gap makes the color and light. So there is nothing in there.

the foam is for holding in place. Here i will give you a link
Holders http://dkc3.digikey.com/PDF/T051/1361-1363.pdf

http://dkc1.digikey.com/US/PDF/T051/P1.html (scroll down to boxes and look there for well boxes.

A good book by Paul Scherz

Practical Electronics for Inventors

link [ame]http://www.amazon.com/exec/obidos/ASIN/0070580782/002-7339852-5666421[/ame]

 

[PlagueWulf]

Aah, I see! I thought you meant the BATTERY exploded! hehe But yeah, I will be careful not to overcharge them, I just have to figure out how.

Good links there, I will attempt to plasticard one for the 9V first. If I am not succsessful (the pictures helped me get the idea to just make one myself) then I will just order some batteryholders.

I dont think I will find the time to read a hole book on the subject (to lazy ) but I will try to find a "quick and dirty" version online.

edit: But I might very well get the book for "later"

 

[Rolex]

Most LEDs only run on 3 to 3 1/2 volts. They should have cooked with 9. Depending on how you wired them, and how many you used, you can run off 9V since enough of them, sharing the current, will create some resistance in the circuit. If I were you, I'd go to your electronics store and ask for resistors to lower the voltage from 9 to somewhere between 3 and 4.
It's been too long since I built circuits, so I don't recall which resistors you'll need. You can also wire them in with 2 penlight batteries. That will give you 3 volts.
The LEDs will work with 9V, but usually they will be much too bright to appreciate the colors, and they will have a very short life.
Wired with the correct voltage, they don't burn out since they give off a 'cold' light.

 

[LazyDave]

The book is good. the first chapter is what you want. the rest is to help you out with ideas. Like how the LED works. You don't have to read all of it. It is a guide line.

to find resistance

Remember V=IR voltage(v)=current(a)resitance(ohms)

if you have let's say two 2.5 lights in a sirries and it is hooked up to a nine volt battery than the voltage=5 (9-(2.5*2)) and it is a 30 ma (0.03). Then the resistor is 4/.03= you need about a 167 ohm resistor.

If it is in parrel then the curent goes up not the volts. So lets say it some how was a 5 volt led. with a current of 70 ma. you have 5 in parrele

5*70=350ma or .35ma voltage=4 (9-5)

4/.35=11.5 ohm resistor. Got it.
rember solve for r.

 

[PlagueWulf]

Rolex: Thanks for the info! I tested it with 3volts and they worked just as fine so maybe I will just use that instead. They have perhaps run for close to an hour on 9v already and the "legs" get hot when connected, maybe thats a bad sign?

Let me attempt to explain the wiring on the LED`s (perhaps its just better to save the pic and zoom in?):
One wire goes from positive on the battery connector to the pos. on first LED - then I go from negative to positive between the others, and finally the last one will be negative so I connect that to neg. on the battery connector.
Then I do the same on the rear lights, and conect them to the same battery connector wire.

Hope that made some sence!?!


LazyDave: Ok, I need the info so I will get that book. The other stuff you wrote made no sence to me (I didnt understand) but I got a 167 and 11.5 ohm resistor from it so I`ll check out the el. store when I am in town and see if they have some of those.

One problem might be that I have no info on the type of LED I got (they are probably from a computer and run on 3v?)? But I want to connect 8 LED`s in whatever way you think is smartest to either a 9v or 3v (like Rolex suggested).

-

Did you see the way it lit up the wall in total darkness? Do you think that would be enough for YOU to drive your R/C in darkness?

edit: OUCH! I tested some different LED`s on 2x 1,2 volt rechargeable batteries with the wires inbetween my fingers (no solder or tape) and it burned my thumb! It made some smoke and now it smells weird here! I got a boo-boo on my finger but I`m ok

 

[Rolex]

The light from the headlights was amazing.
Hot legs on the LEDs is not good. It also sounds like you're wired in series. I would go for parallel when you change to a 3V pack, or you won't get enough light.

 

[t-alec]

Cool Lights

 

[PlagueWulf]

Thank you Rolex and t-alec!

It seems the way I wired the LED`s might have saved them so far from damage, and will run that setup tomorrow for pics/video outside if weather permits. Then I will re-do it after I get the footage to a 3v (or rather 2,4v because I want to use rechargeable batteries there to).

I am looking forward to driving this ouside tomorrow (crosses fingers).

 

[LazyDave]

The series is the beter way in this case. In fact he should be fine. I going to asume that the lights are about, 1 volt not even. it would help if i know the voltage. Then i could lay it out for you.
In the the parrel you need a bigger resitor, this waste to much energy making too much heat. So it can be bad. Insteed use the leds to lower the voltage in a series. as long as the resitance is sligtly < or = the voltage in the bat. That way you don't shortan the life. So yea how many leds you got there?

my LEDs are coming
Ship date
Feb 8, 2005
Estimated delivery date
Feb 14, 2005


Feb 9, 2005 2:34 am
Scanned at FedEx sort facility
ST. PAUL, MN

Feb 8, 2005 5:54 pm
Scanned at FedEx origin location
GRAND FORKS, ND

5:46 pm
Loaded onto trailer at FedEx facility
GRAND FORKS, ND

12:00 am
Customer-Loaded Trailer Picked Up
GRAND FORKS, ND

Feb 7, 2005 10:10 pm
Package information transmitted to FedEx
GRAND FORKS, ND

 

[Rolex]

My point was, if he uses a 3 or 4 volt system, he doesn't need resistors. The LEDs can just be directly wired.

 

[PlagueWulf]

LazyDave: I dont know the forward voltage or any other info on the LED`s unforunately, but I can guess - it works on 2,4 volts, but not on 1,2 volt so somewhere around 2 volts probably? And I will be using 8 LED`s on a single 9v or two 1,2 volt batteries (probably just going with the 2x 1,2v in the future). Hope you can use those numbers?

Rolex: Yes that sounds like the easiest way of doing it. But how many LED`s can you hook up in paralell on a single battery, is there a limit? Or do I just keep adding LED`s until it doesn't work anymore and remove the last one that didnt work?

 

[Rolex]

When they are in parallel, the power to each LED is the same. You won't get less light. Sort of like railroad tracks. One track is + and the other track is -.
Each railroad tie (or LED) is connected to positive on one side, and negative on the other.
That's how you can do it with two 1.5V penlight batts or three 1.2V rechargables, and not use any resistors.

 

[PlagueWulf]

Sweet! I will be trying that (3x 1,2v) after tomorrows bashing session!

I am thinking of doing a stricktly "show" body for my Savage, with some 20ish blue LED`s to light up the ground (below) and sides/wheels of the truck pluss all the other lights around the body (fog/head/roof/brake lights). Sounds like an idea, but its really late and I need to sleep on that one.

 

[Rolex]

Go for it.........Pimp your ride.

 

[JESSE G]

Plaguewulf your truck looks sweet almost looks like a real truck nice job!!!

 

[raver4life2003]

ALWAYS USE RESISTORS PEOPLE. Simple way to calculate what OHM resistor you need you do this:

Input Voltage - LED voltage / LED Amp rating = OHMS

For example say we have a six volt battery and a 3.6volt White LED @ 20mA's we would do this:

6-3.6 / 0.02amps (remember 1000mA = 1amp) = ohms. This would give us 120ohms, thus we need a 120ohm resistor for our 3.6volt white LED to run off of six volts. here's some pictures of my RC10GT with PROPER LED wiring and its very very bright and very driveable and the beam pattern is atleast 8-12 feet infront of my car because they are so low to the ground.

I have 2*10000MCD White LED's and 2*10000MCD Blue LED's upfront, 2 Blue 10000mcd LED's facing down to the ground at the back and two 5000MCD Red LED's at the back with a 60degree angle which is in your face the whole time even if viewed from a 45degree angle from the back. The White LED's are 35degrees and the blue's are 45degree beams. They were bought @ a local electronics store called Active Electronics.

 

[LazyDave]

where you get the 10 thousands? i only saw that in a catalog for optics.

 

[PlagueWulf]

Thank you very much JESSE G!

Rolex: I sleapt on it, and consider it pimped!

Raver4life2003: Those look like they work really well, and look very good aswell. What batteries do you use with your lights?
Oh and thanks for the info on the resistors!

 

[Plaidfish]

raver does that store have a website they sell from?
can U post a link?

 

[Lessen]

those lights seem to work really good from the pics.. good job dude!