okay, i know there are a butt load of LED post, but this is a bit different and i dont think my question is covered (at least in the ones i searched):

i got a red 5mm, 1.7volt 20mA, 3000mcd LED and 330ohm resistors. I know the ones hondahater21 are using are 3.7volt. will i have any trouble with the lower volt LED? do i need a different resistor to compensate?
as you can see im pretty ignant about electronics.
thanks guys

tim

USED TO HAVE...Everything you wish you had, and then some...

You are somebody special Tim, you matter! - from the admins (but nobody likes you, because your username is just like that other guy's, and you whine a lot)

From what I remamber(but im no scientist) You should have no prob with the lower voltage as long as the resistor will handle it. The 3000mcd is the britness (I think?) so It may be brighter. But Im not really sure, I just can pump these suckers out

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yeah you should be fine with that setup... i have been able to use the 330ohm resistor for pretty much all of the leds that ive gotten ie. red, blue, green and used the same resistor.. there is a formula for determining the proper ohm resistor depending on the volts, but cant realy remember it.. but like i said, you should be fine..

-Jason

97 Talon ESi-T (forever in progress...)


95 GS (Gone)
16.74@83.18mph
119.8 whp - 113.3 lbs/ft


2GNT #677
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Ohm's Law is:

Voltage = Amperage * Resistance

holy crap 3000mcd that's pretty bright. The brightest LED I've found was 2000mcd. Anybody have any idea how bright those Varad ones are? I have one of those super small blue LED's for my rear wiper. It's 1000mcd and it's pretty bright.

https://www.jameco.com/Jameco/Products/ProdCT/p031.pdf

they sell leds with mcd of 10000

for a 20ma led at 12 volts you should be using a 500-600 ohm resistor rated at 1/2watt voltage x current =12v x .02mA = .24W but a 1/4 watt resistor will get pretty hot so i recommend 1/2 watt

v=IR 12=.02R
12/.02=600ohm

if everyone is using a 300 ohm resistor thats why everyone is complaining about brightness, you only giving the resistor 1/2 of what it needs..

1998 dodge avenger 4 cyl AT
Mods are:
Not enough

ok.. just some more light on this subject.. the problem isnt really the brightness of the led itself.. its the way the hvac lighting was designed.. it was designed for a regular bulb that shines in all directions and also they are bright.. the leds only output light in a small radius or normally 30 degrees.. and not much output directly from the sides so most of the light output only goes to one part of the hvac assembly.. that is why they appear dimmer than it should.. the blue leds the way i have been using them with the 330ohm resisors are freaking bright. but also blue tends to not look as bright as other colors like yellow or orange.. funny how they came from the facory like that take for instance the blue xenon headlights.. the are technically not as bright as stock yellowish headlights.. but the main thing at fault is the design of the hvac. the only way i see to get them looking or appearing brigter sim to stock would be to place a few more leds in diff locations behind the hvac.. remember there is only one bulb/led that is lighting that thing..

-Jason

97 Talon ESi-T (forever in progress...)


95 GS (Gone)
16.74@83.18mph
119.8 whp - 113.3 lbs/ft


2GNT #677
My Wiki Page: www.2gnt.com/index.php?d=Iamnotwhoiam
Pictures: http://picasaweb.google.com/iamnotwhoiam/Talon/

Has anyone removed the HVAC and put in more LEDs? If you don't know how to remove it, there's a really good how-to with pictures in teh Chilton's manual. It's not hard to do at all.

I can scan the pages if you guys don't have a Chilton's manual. Everyone should have one, though!

yeah i got myself i chiltons too.. first thing i got when i got my car... btw what pages is it on.. i cant recall seeing anything on that... i need to find time to mess with my interior again.. it hs been some time and i need to finish.. as soon as i pull that thing out ill be placing more leds back there. if i do take it apart ill be sure to take pics so others can see how it looks like in real life.

-Jason

97 Talon ESi-T (forever in progress...)


95 GS (Gone)
16.74@83.18mph
119.8 whp - 113.3 lbs/ft


2GNT #677
My Wiki Page: www.2gnt.com/index.php?d=Iamnotwhoiam
Pictures: http://picasaweb.google.com/iamnotwhoiam/Talon/

CHASSIS ELECTRICAL 6-14 and 6-15. I have the one for Eclipse 1990-1998. Book# 504000.

yes the viewing angle for blue led's is very bad the best ive found is 45 degree spread (all other colors are 60to100deg), it is $2.67ea. at www.digikey.com part number LNG91LCFBW

another thing to note about blue led's only is that they are static sensative

1998 dodge avenger 4 cyl AT
Mods are:
Not enough

Woah! can i have that in english, mcgyvr? so i need a 500-600ohm resistor for the specific LED i mentioned in the post?


im only going for lighting the little amber tics on the dials, cause i have custom gauges that are already red.

USED TO HAVE...Everything you wish you had, and then some...

You are somebody special Tim, you matter! - from the admins (but nobody likes you, because your username is just like that other guy's, and you whine a lot)

well that seems funny to me cause i have used a 3000mcd LED and a 300 mcd LED with the same resistors and the 300 one is alot brighter. look at the watts on the package of the LED. it's just like a regular bulb, the highter the watts the brighter.