5v led run on 12v?

T

TeleFragger

[H]ard|Gawd
Joined
Nov 10, 2005
Messages
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Ok so I am getting ready to start modding my antec 900 case..
anyhow... I took apart an old tiger direct piece of crap case..

the case was silver and had 1 led bars run up and down on each side of the case...
so I took it all apart.. and apears to be just a led on each side of the clear bar....

so they work and work nice... however I want to put a toggle switch in and the toggle switch lights up too....
well since I took the led off the case.. they had a power plug... which has a black and red wire... thus ground and 5v....

the switch I wish to use was from my truck when I had my kc daylighter lights hooked up to them.... so they are 12v switches.... they are illuminating at 5v but dull.... so how can one tell if the led's can handle 12v? or is that just going to be a neigh??????

Thanks
~Jeff
 
They would probably fry pretty quickly if not instantly I'd think.
If you have a radio shack nearby pickup a couple switches, probably
only run you about a few bucks.
 
TopGun said:
They would probably fry pretty quickly if not instantly I'd think.
If you have a radio shack nearby pickup a couple switches, probably
only run you about a few bucks.
Click to expand...

yeah... I have 4 blue lit switches... got them from radioshack a while ago...
they look like this...

the only shot of the switches is here..

switches.jpg



also for the hell of it I hooked up these led's to 12v.. (yellow wire) and they did not go poof... and my switch was brighter!!!!!! YAY... well for now...


I was going to use contura rocker switches on my case... as I have most of the parts... but figured id use these instead...

the conturas I have are these..which I have used in place of my ac vent in my truck...
rightswitches.jpg

and
leftswitches.jpg




this case modding is new for me.... truck modding is not new....

here is a pic of my baby.... currently getting worked on once it gets a tad warmer... SOB... SNIFF... SNIFF...

rootbreaker4.jpg
 
So how did the LEDs in the junky case get hooked up to power? I wouldn't assume that since they had a red and a black wire, that they ran off 5V, although it is probably that way.

If they did run off 5V, then all you need to do is figure out how much current they draw, and insert an appropriate resistor. For example, if there are two light bars, each with two LEDs, then they'll probably draw roughly 80mA total. You need to drop that 12V down to 5V, so (V=IR) (12V-5V)/.08A = 87ish Ohms. Any resistor within about 15% of that value is probably close enough. Another alternative is to get a 5V regulator and solder that in place. Either way, you can pick up the parts at RadioShack (not the first choice for electronics hobbyists, but when you only need one part, it'll do.) Regulator here.
 
It looks like the current-limiting resistor is hiding in the heatshrink on the blue wires. It's not a great design, but easiest to leave it alone for now. I'd suggest simply adding another resistor in series. One of these should do the trick nicely.
 
I hooked a blue led up to a 12V main once. It was orange, for about 5 seconds, and then it exploded :D Nothing like the smell of InGaAs in the morning :)
 
If you give it 12V source, and it requires 5 volts, the LED like mwarps said, will live a short life.
 
Ang said:
If you give it 12V source, and it requires 5 volts, the LED like mwarps said, will live a short life.
Click to expand...

well almost killed the machine.... smoke galore!!!!!!
so switch is out now... and led are now hooked up to 5v and straight to power... always on....

looks nice too...
 
Mohonri said:
What did you blow up? Curious minds want to know.
Click to expand...

well I was trying to get my water cool running... well i couldnt get the system to bleed right and pump.... so I took it apart.. when I did that.. I had to unhook the switch...
well when I put the pump/tank back in... the switch wires were hanging...

lets say +12v and -Gnd = instant smoke :eek: .... thank god I only melted the thin wires that were going to the switch....

everything is running ok... machine is up and good...
 
I need to get back to the truck... didnt touch it last year and havent really this year either...

see more here
http://www.supermotors.net/vehicles/registry/8011



plot said:
off topic: nice snorkel
Click to expand...

thanks...
toyota landcruizer Fj-80
bought from here
http://www.4by4connection.com/toyota2.html

I paid less as the prices have gone up... but soooo nice...

$20 home depot and $10 junkyard carb adapter as I have a holley truck avenger 670cfm and needed to raise the stock breather over the bowls on the carb... (qjet standard doesnt have this problem)

snorkel.jpg


Private_Ops said:
I see a GMC!! Is it a Sonoma or Jimmy? I've got a ZR2 Blazer myself (despite the gas sucking hog it is, working on getting a 4cyl 5spd something to drive to school).

//back on topic now
Click to expand...

that GMC is now gone... ticked me off.. so I replaced it with a 2005 trailblazer ext....

just a 1996 gmc jimmy 4 door... 4.3l vortec.... heater core was going bad, bad oil leak, replaced fuel pump and dented the tank so at a red light and 1/4 tank it would sputter as running out of gas unless you tapped the gas..needed other work too....

my DD is a 1996 camaro (v6) sucks on gas mileage too but paid for and has 194,000 miles right now... it is dieing but I need it to last 2 more years....
 
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