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First I solder the L.E.Ds Togethor:
I put the resistor on the Negative - End:
Now I soldered the connections:
I hook the wires up correctly to my test power supply:
Then I hook them up + to yellow - to black:
And there you go 3 Green LEDs Lite and Bright. 8)
Resistors are: Brown Green Brown Gold
wait shouldnt those led's blow? 3.6x3 isnt more than 12v, shouldnt they blow out?
Well you could wire them Up 2x2. I had a long conversation with bucko and xmastree and They come to the conclusion I needed the Brown green brown gold resistors.
Here is what I have going with the same configuration.
For my Saturn Magnetos Mod: The max is 3.6
I don't know the specifics on the voltages ohms I just go by what works.
I'd be great if someone added to it.
To the best of my knowledge it is correct, ugly but correct.
That's a pretty cool way to demonstrate! +Rep, even if it turns out it's gonna blow up. :)
-Dave
That's what the resistor is for.Quote:
Originally Posted by MaxOC
Haha, this is the best led tutorial i have seen...
the diagrams are good :D
+rep for such a great way on how to explain
a good thing to add to is how do you know what are the + and - of a led. i remember it as the fat and skinny parts in the led
si-skyline
I try. Here is the link to some wizards so you can make your own diagram.
http://led.linear1.org/led.wiz
http://www.metku.net/index.html?path...calc/index_eng
Awesome Tutorial,
I learned something new today. Thx. +Rep
Glad you got it sorted out with Xmastree's and my help.
i didn't get this the first time. Then i read it again and i saw how it worked. Nice! i will be using this.
But how do you add extra wiring to the PSU?
You can use a molex connector. :)
There's a real easy way to connect extra wires to a molex, and it looks like it was made that way. Remind me to do a how-to sometime.
reminded xD
Reminded again.
Ok, ok, ... I have an old PC in the cellar I can use. Watch this space...
Here you go...
http://www.thebestcasescenario.com/f...d.php?p=172799
nice guide thanks for that going to go play later as long as i find the LED's i want :)
just a question though, why put the resistor at the negative end? a few of the wiring diagrams put it at the begining and some put it at the end.
Thanks
Jim
When wiring an LED you have three options:
1.wire each LED single with its own resistor
2.wire multiple LED's in Series with a single resistor
3.wire multiple LED's in Parallel with a single resistor
Your current-limiting resistor can be connected to either
the positive or negative side of the LED, it doesn't matter.
What matters is the direction of current flow, since an LED is a type of diode, and for a diode to conduct, it must be forward biased. This means that the positive voltage must be connected to the anode, and the negative to the cathode the shorter lead.
Here is a LED Circuitry Tutorial.
Thanks for the response,
I've already read that tutorial, i just wondered why people had done it differently i personally would have thought it would have gone at the front before the diodes.
I must admit im unsure where to go at current as i was tempted to run 2 series of 4 in parallel, though im not sure.
I think running them in parrallel would be better but wasnt sure.
i have 8 Red 2.5 volt LEDs which would run at 20mA.
the way i saw it was 1 of 3 ways.
* 2 series of 4 LEDs in parallel with a 120 ohm resistor at 1/4w on each series.
* 1 parallel circuit with a 68ohm resistor at 2w at the beginning of the series.
* 1 parallel with a resistor on each LED however i have no idea how to work out what ohm / w i need for that.
anyone got any golden advise on which way i should potentially go.
It makes no difference whatsoever.Quote:
Originally Posted by JimChud
That's what I'd do, assuming I understand you correctly. Two strings, each comprising four LED's and one resistor in series. Fed from 12V.Quote:
* 2 series of 4 LEDs in parallel with a 120 ohm resistor at 1/4w on each series.
120R will give you 16.6mA which ought to be fine. 100R will give 20mA.
great tutorial, so what excactly does a resistor do i was taught in scince but i didnt really listen/ understand show if someone here could tell me what they do would be great.
it coverts a certain amount of energy in to heat and thus reduces the energy in the circuit.
Well, yes, but that's not really why we use them.Quote:
Originally Posted by JimChud
It controls the current in a circuit. Current through a resistor is proportional to the voltage across it. Double the voltage, double the current.
In an LED circuit, you need to control the current through the LED. The resistor does this.
An LED has a certain operating voltage. In this case it's 2.5V. Put a higher voltage across it and it will attempt to drag that voltage back down to 2.5V by drawing so much current that the power supply drops. Obviously, with a computer PSU, it will take a LOT of current to achieve this, and the LED will simply burn out. With the resistor in place, the resistor will limit the current for you.
Yes, I tried a 3 watt LED directly through my 550W PSU, I think on a 12-volt rail, and it got very hot, so I let it drop within a second. It was scorched and burned, and would not work again when I tried it.
that is precisely why we use resistors.Quote:
Originally Posted by nevermind1534
i wouldnt be shocked if you popped it.
i would recommend looking at the above LED Guide to see what you need :)
I've got some LEDs already matched with resistors, so I think I will run them all in parallel off of a 5V rail. It is going to be for a school project, and I'm only powering a fan and the LEDs.
