I never got the difference between leds in series and parallel. i looked at some pics but they look confusing. and wuts better for lighting a jewel

http://physics.bu.edu/py106/notes/Circuits.html

I would wire them in parallel.

I did wire in some speakers in a series one time and they sucked so I did it parallel and they slammed. I just think of that when im wiring shit up.

For sure parallel when you wire in series you they all draw off the same voltage and they will not be as bright. if you wire them in series the same voltage will go thorough each one it is a much better way of wireing.

alright. i should wire them in a parallel. now the problem is i still dont get how to wire them. how do i kno if im wire them in a series or parallel. is it in a parallel do wire 1 resistor before the leds.

n i have no idea how u wire a series.

im a newb when it comes to this

it could work either way. I could probably draw you a good schematic if you tell me what voltage source you're using as well as the number of LED's. Also tell me the recommended voltage drop across each LED and the recommended current (this might be under I or current, and it will be labeled in mA probably)
That stuff should be on the LED package

thomes08

Parallel is all the neg sides together and all the positive sides together.


Its not that hard. Wire all the LONG parts to the other LONG parts and all the short parts to the other ones on LEDS and then stick the ends to their pos - neg parts of the wiring and fire it up.

im gonna light the jewel so i guess im using teh power the runs to the hd.

8leds
3.3 voltage drop
20 mA

i think you would be better off using 6 2V 10-20 mA LED's

If you run this off 12 volts...

IN SERIES you won't be able to drop 3.3V across all of the LED's, and if they're in parallel dropping 3.3V then you won't be able to get 20mA across each one. That's just some quick thinking there is a good chance i'm wrong it's friday night and i've already done 2 hours of HW and i'm drinkin a 40 (st. ides) so i'm losing motivation for the night
someone can think about that for me or i'll think about it in the morning

thomes08

Red is 5+ yellow is 12+

just so he ^^ doesn't look dumb i asked what voltages are the yellow and red wires in a molex cable.... i edited my post after i had a different view on it

thomes08

so i should use 6 leds in a parallel of the 12v?

i have a wireing diagram here man:

a 100 ohm resistor can handle that many leds? what is the max i know theres tuts for this but im too lazy/stupid to figure it out.

yeah man i put that many on it works fine cuz it dosent matter how many leds u hook up when u r doing parallel

ya it does doesn't it divide the current?

thomes08

no it provides resistance

aite thanks for the help. i pretty much get it now

i know if you have 30 mA going across say, i dunno, 3 resistors in parallel you're going to get 10mA across each one. It's Kirchoff's (spelling) current law

edit: 3 resistors of equal value

Huh? Everything I've been reading on "real" (i.e. not mod-related) electronics pages says that connecting LEDs in parallel is a bad idea.

The way I understood it is that basically there are variances in manufacturing that make LEDs very slightly different, even though the specs may be the same on the packaging. Because of this, one LED will draw more current than the others, and become warmer, thus more conductive, and will keep drawing more and more current until it exceeds its limit and burns out.

Of course, I haven't been reading about this stuff long and am still trying to understand the basics, so I may be missing something here...

Here is my problem..

I used this tutorial http://mywebpages.comcast.net/ben999000/ledtutorial/ and I followed it exactly except where he used 5mm blue leds i used 3mm red leds.

Well here is the problem It works great using a 100ohm resistor but I used the led calculator and it told me I should use a 22ohm resistor and so i went out and bought a 22 ohm resistor. When I solder it on it gets too hot and breaks the connection where I soldered. So its getting too hot whats wrong? The 100ohm is nice but its not as bright as I want it cuz these leds get way brighter

Finnaly a pic that is easy to understand..

Thanks IITangoCrazy

are you some kind of moron yes that is kerchoffs current law but it doesnt have anything to do with that. the drawing works i did it what it is doing is divding current amongst those the resistor is in series and effects them all V=IR

It all depends too on what LEDs you are using there are so many variables here that you cant just use a specific resistor i did this to show a guy what he needed after he told me what he had. it just happend to be a 100 ohm resistor he needed.

but that is exactly how you should wire LEDs to get the best perfomance out of them.

I know nothing about freaking leds or better yet anything about electricity and resistors and shit.. But what ever thanks for you help anyway.. If it was any help

let me come in here and clean up the noobness from this thread:

Kirchoff's Current Law: The algebraic sum of the currents into a node = 0

wiring in series: voltage divided among components, current remains constant
wiring in parallel: current divided among components, voltage remains constant

There are no "negative" wires on a fan connector or a molex connector. there are two positive connectors (one +12V and one +5V) on the fan connector, and a +12V (Yellow), +5V(Red), and two GND (Black) wires on the molex collector. Hook up the positive (long) leg of the LED to the higher (if applicable) positive voltage, and the negative (short) end to eithe GND or the lower positive voltage. LED's can only be wired one way, because they only allow current to travel in one direction (ideally; most allow some current to go the other way, though a negligible amount).

LED's technically should be wired in series, but the xbox only provides enough voltage to power about 3 or 4 LED's at once if they're wired in series. Thus, you need to use parallel, so instead of dividing up the voltage, you divide up the current, which is more abundant in this case.

a 100 ohm resistor hooked up to +12 and the LED's in parallel will probably be good, and will compensate for the safety factor of components, meaning the difference the amount of power they can take ideally and the amount of power they can take in reality. Hope this helps you guys. If you have questions, ask in this thread.


Edit: oh, and hooking too many LED's in parallel IS possible. You can't wire too many LED's together, because then it takes too much current from the power supply (wattage of the power supply determines this) and causes adverse effects on the rest of the xbox (hard drive, processors, etc. not getting enough current).

Ok perhaps this was not explained well. He had done the 12 volt fan mod and that is why it was the way it was. so his fan was not stock so it worked if that clears it up for you guys. Also i just called the ground the negative cuz it was easier for the guy to understand. If you try to explain it with a ground it fucks people who dont understand wiring up but everyone knows wiring as positive and negative.

There's nothing better then a bunch of people who know a little about electronics trying to explani it to the rest of us This is awesome.

i was just wondering after looking at that lil pic thing, do you have to close the loop in parallel or can it just "end" like that.