New LED way to bright...resistor?

I finally ordered a single small LED to light up the cup holder/storage area.



The LED has about 4" of ribbon that attaches to the actual LED which I ran through the hole (in red)



now its WAY too bright..and the pic really doesnt do it justice. My question is will a resistor in-line dim it enough to some what match the dash lights? If so what size/rating?

 

bump...

 

what are your specs on your led? such as voltage and current rating?
also look up dc constant current regulators, you can typically find them for 3-5 dollars and some of them are fully adjustable so you can turn a dial and adjust how bright they are.

http://www.prodctodc.com/dc-to-dc-7...ed-driver-power-supply-p-57.html#.UN5jF3fwmSo

something like this, their only draw back is that they ship from china, I am sure you can find a good u.s. dealer if you want it any sooner than about a week and a half

 

yes a small knob for variable resistance will work great (dimming)
get a cheapo multipack from radioshack and test which works best
(caveman method)

or figure it out here http://bit.ly/ZHZmK9

 

heres the actual LED I installed

http://www.superbrightleds.com/moreinfo/surface-mount-smd/little-dot-smd-led-accent-light/639/

thanks for the responses. I dont really want to go with another dimmer switch. I'm gonna tie it into the one on the dash now.

 

Don't do that! Trust me, you'll fry your dimmer switch and its like $100 from the dealer.

If its too bright and you don't want to add a dimmer, then yes, a resistor will work. BUT, it will get very very hot and unless you have a secure place to put it (which really is nowhere down there, ESPECIALLY with your SRS module right there) then I recommend against this method.

You bought an SMD led. Also referred to as SMT depending on the led. That led is designed to be super bright. Its part of the technology. Notice how its flat, square shaped, and appears yellow... that means its bright! You need a regular simple let like this:




LEDs are so cheap, I recommend skipping all the hassle of trying to make it less bright when you can spend less than $1 and just get the correct led. Trust me, don't thr to get fancy... your stock dimming circuit is very sensitive and you run an EXTREMELY high risk of blowing out your entire dashboard lighting if you do it your way! Trust me, I've seen I happen

 

i would put it on a switch. thats my plain. i plain on adding a small LED to each cup holder and the small storage in front of them, they will all be green or red and on a switch.

edit: that way you can just turn it off. and than turn it on if you want it on.

 

I used these from ebay in my cupholders.http://www.ebay.com/itm/10-PCS-LED-...863?pt=LH_DefaultDomain_0&hash=item4abefb1cd7 I tapped into the dimmable lighting wires for the HVAC contols. As long as I dont dim the dash lights My circuit should be ok as these have resistors built in correct??

 

Sorry bad link, try this one..http://www.ebay.com/itm/10-PCS-LED-...863?pt=LH_DefaultDomain_0&hash=item4abefb1cd7

 

I knew the one i ordered was gonna be bright but i didn't realize just how bright. Also the ear of installation was a big factor too. I would like to go with a much dimmer led like the one pictured. is there a flush mount one like it?

 

^^^ This! Gotta love the K.I.S.S. method!

 

Ultimately the advice to use a dimmer LED is the best advice. To answer your question, yes, you could add a resistor in series (in line with the positive or negative lead) if there is only an LED in the circuit. To drop the brightness, you may need a 220 Ohm, or even upto 470 Ohm. This will drop the available voltage by 3V (220 Ohm) and may begin to lower the current to the LED.

however,
The specs for the LED state a 9-15VDC range. This means they may have included a Current controlled device with the LED. Its job is to maintain the 15mA current the LED needs, regardless of the input voltage. In that case a resistor may still work, but you would need to drop the voltage below 9V, outside of the operating range of the current control. You'll have to experiment with resistor values, starting with 220 Ohm, and work your way higher until the LED dims, or shuts off.

The LED should light with as little as half of its intended current drive (7mA) and produce much less light. A resistor power rating of 1/4Watt will be fine.

 

Also both ebay links are bad. So just run the resistor in-line right? Is it going to get hot enough to where I have to be concerned about melting anything?...thanks again man!

 

The inline resistor will not get hot enough to start any fires or melt anything.
The calculations are:

15mA LED current (max) = .015A
.015 Amps * 220 Ohm resistor = 3.3Volt (drop)
Power = .015A * .015A * 220Ohm = .0495 Watts (1/4Watt resistor = .250 Watt)

As a comparison your turn signal filament bulb is something like 20Watts, most of it as heat!

 

You are awesome. Thank you.

 

Ended up having to go with a 2.2k ohm resistor. It's so much better now.thank you again.

 

good to hear it worked out for you Pat! Thanks for the reply.