LED Question

[gr8archer]

I have been reading threads about headlights, but im confused about wireing LEDs. I want to buy 2 of the LEDs at the site listed below but im not sure if a 6v battery pack would power 2 of them. I tried a LED Resistor Calculatior and it just freaked out and said not enough power. How can 6v not run 2 LEDs? Is there anyone better at this math and electronics crap then me that can help me out? Thanks.

http://www.lsdiodes.com/shop/index.p...products_id=37

[STEEL_CITY_CRAWLER]

well, let me the first to say, use the search button. also, i might also suggest going to the local radio shack and asking them, a lot of times most of the people that work there actually know about about the electronic stuff they sell there!!! PLUS.... you probabally won't have to wait/pay for shipping cause it will probabally be in stock!!!

[Crawlsalot]

x2 on the go to radio shack.

[gone_wheelin]

From my experience with the staff at the local Radio Shack, you're lucky if the one person on staff that knows anything worth a damn is working the day you go in.

Looking at the link you provided it looks like each LED requires a forward voltage of 3.6v. If you want to use 2 of them then I believe you would need 7.2v. If you powered them with a 6 cell pack in series you should be okay or you could run them in parallel with 6v and the correct resistance to bring the 6v down to 3.6v at the LED.

[JohnRobHolmes]

You could run the two LEDs in parallel and run them from 6v, but you would need a resistor in series with each one to drop the proper voltage. If you ran the LEDs in series the 6v would not work.

[STEEL_CITY_CRAWLER]

Originally Posted by gone_wheelin

From my experience with the staff at the local Radio Shack, you're lucky if the one person on staff that knows anything worth a damn is working the day you go in.

OH yeah, forgot to mention the RS that i rugularly go to is and old one, with old guys that have been there since the chain started!!! those guys know their stuff...

[gr8archer]

Ok, so I need to put it in parallel. How do I go about wiring resistors into the system? I made the two drawings below in paint but I cant figure out which one would work. Or what resistor I would need...

[JohnRobHolmes]

either way should net the same result. In drawing one the resistor will see double the watts of #2.

To find out what resistor you need, you need the specs of the led's. Instead of doing the math for you, read up on this http://www.kpsec.freeuk.com/components/led.htm

It has all the info needed.

[fatrat496]

I'd go with the second drawing. Use a resistor for each led. I'll have to say though, the guys in my local radio hut are tards.

[envious8420]

Originally Posted by johnrobholmes

either way should net the same result. In drawing one the resistor will see double the watts of #2.

To find out what resistor you need, you need the specs of the led's. Instead of doing the math for you, read up on this http://www.kpsec.freeuk.com/components/led.htm

It has all the info needed.

theres some great info on this site.
now im going to hit rs and pick up some leds and resistors

[bugman72]

Here is the best LED calculator that I've come across in a while.

http://led.linear1.org/led.wiz

Not only will it determine what resistors you need, it will show you a wiring diagram so wiring and installation are virtually foolproof. I'm planning to do a star ceiling in my theater using LEDs and this little calculator was able to tell me what resistors I needed to power 800 (yes...800 LEDs) off of a 12V 6A power supply. It also showed me two ways to wire all of them.

I'd be hesitant in picking up any LEDs from Radio Shack. Generally speaking, the LEDs that RS sells are low mcd (light output). If you want to use some LEDs as headlights, you need to use some that are AT LEAST 8,000mcd or greater. When I first got my Nylint, I added a pair of 10,000 mcd white LEDs and it was almost blinding to look directly at them.

Here's a great (and cheap!) site to get LEDs.

http://www.ledshoppe.com/index.html

[racerx]

What's wrong with kits like the one's from RAM? They have been at this R/C light stuff for awhile now, why not just get one of these?

[peej410]

i strapped my 1watt Led headlamp i use for work to my crawler and when it was aimed right the thing was SICK http://www.quickar.com/lux.php?session=SNClMZ1e a quick google came up with this...

[JohnRobHolmes]

Bugman, what are you not capable of doing? I mean really, is there anything you cant wire up or program?

[RATBASTARD808]

Here is another great place to buy led's.

http://www.modsthatglow.com/

Check out the glow in the dark pigments http://www.modsthatglow.com/pigments/green__SrAl2O4.htm

I wouldn't mind putting some of that mix into my next paint job.

I will take some pics of my RC18MT with 4 white and 2 blue led's powered with 4.6v battery pack and 47ohm resistor.

I am planning to build another set of led for the crawler, and have them run like flood lights front, rear, and below the chassis.

RB808

[bugman72]

Originally Posted by johnrobholmes

Bugman, what are you not capable of doing? I mean really, is there anything you cant wire up or program?

It's funny that YOU say that, because Tony and I often feel the same way about you!!

A lot of my knowledge of LEDs in particular come from modding Xboxes. I've added LEDs in places that I shouldn't have (like the X, Y, A and B buttons on my controller as well as creating a lit up "XBOX" on my drive tray with no wires!)



Rat, I did something very similar to what you were talking about doing with my Nylint a while back. I didn't have any taillights, but I did have a set of headlights and four crawling lights (all 10000mcd white). Uber bright and looked cool as heck! I'll have to see if I can locate a couple of pictures of it (just deleted the darned directory from Photobucket).