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#### TheChris2233

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I am looking to change Raven RV03 front LED. Currently it looks to be single "tailed" LED. Diameter looks to be 5mm. It looks similiar to these:

I would like to change red LED to be blue. Can I just snip the ends of the red led, strip back the cable some, and "tie" in new blue led with some electrical tape? Is there a better way to do it?

While on that topic, does anyone know a good place to get low intensity LEDs? Or a good place for these "tailed" LEDs other than frozencpu.

Thanks.

#### kill

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Your method would work if you secure it enough and know which way is +
i would suggest soldering it though

#### crimsontears809739

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Let me know if i loose you in the terminology.

Time for Basic Electronics 101:

Different color LED's require different amounts of current. Each LED will have a data sheet that specifies the max current. The more current you use, the brighter the LED. Go over the max current, and you burn out the LED.

Therefore, you need a current limiting resistor in series with the LED. If you change the color LED, you need to change the current limiting resistor. I have never bought a tailed LED, but it appears a "tailed" LED has the correct current limiting resistor built in.

I do not know a good place to buy a "tailed" LED, but i know where you can buy all the parts to tail it yourself. Digi-Key (www.digikey.com/) is the Wallmart of electronics parts. They will have everything you need to tail the LED yourself.

The math to calculate the correct current limiting resistor value is VERY simple.

V = I * R. Where V is voltage measured in volts, I is current measured in amps, and R is resistance measured in Ohms.

You can you electrical tape, but considered a "poor practice". The best method is to use shrink tubing. That is what the "tailed" LED's on Frozen CPU use.

Use this Wizard to calculate resistors, and for a picture of how to wire up your LED's --> http://led.linear1.org/led.wiz

Also, A resistor that you can change it's resistance is called a Potentiometer. If you use a potentiometer as your current limiting resistor, you can change the brightness of the LED to suit your needs. Potentiometer are cheap, about \$0.10 each.

I can take some of the head ache out of searching for the LED's. Let me know the size of the LED's and how you plan to mount them, and i'll pull up the right page for you Digi-Key.

I can also pull up links for a cheap soldering iron and shrink tubing if you want.

#### TheChris2233

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Quote:
Originally Posted by crimsontears809739

Let me know if i loose you in the terminology.
Time for Basic Electronics 101:
Different color LED's require different amounts of current. Each LED will have a data sheet that specifies the max current. The more current you use, the brighter the LED. Go over the max current, and you burn out the LED.
Therefore, you need a current limiting resistor in series with the LED. If you change the color LED, you need to change the current limiting resistor. I have never bought a tailed LED, but it appears a "tailed" LED has the correct current limiting resistor built in.
I do not know a good place to buy a "tailed" LED, but i know where you can buy all the parts to tail it yourself. Digi-Key (www.digikey.com/) is the Wallmart of electronics parts. They will have everything you need to tail the LED yourself.
The math to calculate the correct current limiting resistor value is VERY simple.
V = I * R. Where V is voltage measured in volts, I is current measured in amps, and R is resistance measured in Ohms.
You can you electrical tape, but considered a "poor practice". The best method is to use shrink tubing. That is what the "tailed" LED's on Frozen CPU use.
Use this Wizard to calculate resistors, and for a picture of how to wire up your LED's --> http://led.linear1.org/led.wiz
Also, A resistor that you can change it's resistance is called a Potentiometer. If you use a potentiometer as your current limiting resistor, you can change the brightness of the LED to suit your needs. Potentiometer are cheap, about \$0.10 each.
I can take some of the head ache out of searching for the LED's. Let me know the size of the LED's and how you plan to mount them, and i'll pull up the right page for you Digi-Key.
I can also pull up links for a cheap soldering iron and shrink tubing if you want.
The old LED was just LED with leads soldered to wires, shrink tubed, and running to + and - "HDD activitvy" motherboard connectors. You mention need of a current limiting resistor. Can you explain this more? As far as I can tell, there is no resistor for the old LED.

After pulling the cable tail loose, I de-soldered the old LED and soldered / heat shrunk the new one. My shrink tube was 1 size too big for the small wires so I secured the shrink tubing with electric tape. I'm still working on PC build but a test with LED and a 3v battery went fine.

The LED I used has the following printed on the package

front:
5mm Blue LED
3.7v
30MA
2600mcd

back
Forward(supply) voltage - 3.7typ 4.5max
Forward(supply) current - 20mA typ 30mA max
Luminous Intensity - 2600mcd
peak emmision wave length(nm) - 468 typ
Viewing angle - 30
Lens color - clear

#### crimsontears809739

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I just did some research and it seems that motherboards have a LED driver automatically built into the +/- pins for the LED's, which does automatic current limiting on LEDs. No resistor is necessary...so disregard my whole rant about calculating a resistor.
I feel stupid now.

( If you hook a LED directly to a molex connector on a power supply, you need a resistor. That was my previous experience with LED's. )

Your motherboard + and - pins for the HDD are 3.3V to the best of my knowledge (you should double check with a multi-meter to make sure i'm correct). The blue LED you picked out has a 3.7 V drop. The LED won't be in full saturation if I'm correct. Your LED is close enough where it should still work, it just might not run at full brightness. If you LED doesn't light up, it's because it needs more voltage. If you have that problem, I know a few ways to get around it.

#### TheChris2233

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LED lights up and is bright as hell. If it wasn't for white plastic it is behind, it would be too bright. It may STILL be too bright but it was only 5mm blue LED radioshack had. If I find it bothersome, I'll just order a lesser one I suppose. It was lighting up with 3v battery so 3.3v from mobo should be fine and as I mentioned earlier, I don't mind it NOT running at full brightness.

Thanks for the info that is good to know. I took some pics of where I replaced the LED and also reached out and got some replies from silverstone test support. I'll add all of that in later.

I scoured the internet for a long time trying to find somewhere someone had experience with this and eventually ended up "winging it" so hopefully it will help someone else.

Thanks again for the info

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