# Cabinet Mod  . . . . .LED



## int86 (Aug 23, 2006)

I would like to light 4 LED in series(12V). It is easy to draw its power from SMPS. But i would like to lit it only when hard disk light is on. But its poweq will not come fr HD light. is there any electronics that will just send on/signals. The light should work simultanously. Please no use of photo diode. The circuit suggested must be simple. 
This mod will be a meanigful.
Send the circuit dia.


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## john_the_ultimate (Aug 24, 2006)

Take a molex (4-pin) adapter....prefrebly the one with both male and female connectors. Then conect the +ve pin of the LED to the red (12V) wire and the subsequently connect the -ve pin to the +ve pin of the next LED using some thin gauge wire. At the end connect the -ve pin of the last LED to the black (ground) wire of thr molex connector. 
U can do is take 4 (four) 3V LED and connect or else u will have to use a resistor, depending on the rating of the LED. You have 12V to play with so, 3V*4 = 12V. But do connect LEDs of same value. 
Then connect this whole setup to a free molex connector of ur SMPS. So when u power up the system the LEDs will also light up. 

See this for more info: *www.kpsec.freeuk.com/components/led.htm


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## int86 (Aug 24, 2006)

Thankx jhone 4 ur link.
But the LEDs should go on an off as hard disk light. It should work as hard disk light. I think best mthod is some type of signalling circuit fr HD light connector.


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## Rollercoaster (Aug 24, 2006)

U need a transisiter drivin LED circuit. similar to circuits used to switch relays.

Use a transister like BC147 aka BC547. Connect the center pin to the +ve of teh HDD LED thru a 120 Ohms 1/4 watt resistor. Then connect right leg of the transistor to black wire from the SMPS. Then connect the left leg of the transister to the yellow SMPS wire thru 4 LEDs in series.

U are Done.


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## int86 (Aug 24, 2006)

Thankx roller, u always help me.
I would like to ask u some more:
1. There should not be any flow current flow HD light. It should light as usual.
2. Which is best BC147 or BC547. And means "aka".
3.what all this cost, as local vendor cannot cheat me as i m newbie.
4. Center pin is ok but how to find left and right pin. 

After googling i found how to find +ve led of LED.


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## Rollercoaster (Aug 24, 2006)

he he... u r really a newbie at electronics... it is so refreshing...

anyways BC147 and BC547 are same transisters.. which ever is available get that. Cost would be less then 5rs as these are main stream items. Well there would be a very very small current flow from the HDD LED to the transister base which is unavoidable. u have to get some signal to make the transister know.. right? btw the current is so low that u wont be able to monitor it even with a digital multimeter...dont worry it wont affect ur mobo, if thatx what u are concerned abt...


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## int86 (Aug 24, 2006)

Thankx again ROLLERCOSTER.
  U didnot told what word "aka" means.
Most important how to find left and right end of transistor. It depends on how i hold it.
It will not just a eye candy modification. I found that best way to understan electronic is to do it. Right


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## samrulez (Aug 25, 2006)

a.k.a=as known as (in think)


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## janitha (Aug 25, 2006)

samrulez said:
			
		

> a.k.a=as known as (in think)



No. "also known as"
__________


			
				int86 said:
			
		

> Thankx again ROLLERCOSTER.
> U didnot told what word "aka" means.
> Most important how to find left and right end of transistor. It depends on how i hold it.
> It will not just a eye candy modification. I found that best way to understan electronic is to do it. Right



The pins of a transistor are not left, right, top etc.
They are Collector, Emittor and Base. For pin configurations of common transistors refer to the following link
*hamradio.lakki.iki.fi/new/Datasheets/transistor_pinouts/


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## Rollercoaster (Aug 25, 2006)

Here u go... the circuit... Since u were concerned with the current drawn from the HDD LED i modefied the ckt a bit.

*img168.imageshack.us/img168/3467/hddleddl0.jpg

*VR1* - VR1 is a preset available for <10Rs. The view shown is the pic is *top view*. It is a variable resistance. Buy one. Connect it using the two pins marked by red dot eitherway. Now before power ON turn the dial on the preset fully to the right with a screw driver. Now power on. If ur LEDS dont glow then start turning the dial to the left slowly and keep turning untill u have max brightness. Stop turning when u have bright enough LEDS. Be Carefull not to turn more if the brightness stops increasing and start turning right now till u see the Brightness start to go down slightly. you are done. Now u are drawing the lowest possible power from the mobo. This circuit is completely safe. 

And hey, do some 3-4GB data copy or run degragmenter to keep the HDD LED ON so that u can see the new added ones to light up.

BTW aka means 'also known as'
__________
.
*TIP* - For testing u can connect the redwire from the SMPS to the 1K resister insted of the HDD LED+ve wire. After connectiong and adjusting VR1 remove and reconnect the red wire a couple of times to see the LEDs go ON n OFF. But u need to re-adjust VR1 after testing when u connect to HDD LED wire.
__________


			
				janitha said:
			
		

> The pins of a transistor are not left, right, top etc.
> They are Collector, Emittor and Base.


So nice of u to educate me on the matter. And i suppose using ur words a noob can understand better. Very informative!
.
.


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## int86 (Aug 25, 2006)

Only time is matter now. U will hear soon. Roller


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## janitha (Aug 25, 2006)

@Rollercoaster
I was not trying to educate you and I was answering someone else.


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## aku (Aug 25, 2006)

@mods
well fellas dont u think dat this thread should rather be shifted to the Tutorials section???. very informative.. roller.. kip up da good word...


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## int86 (Aug 25, 2006)

Roller,
some guys r finding this simple idea useful.
Today i only got BC548. The local guy told me it will work as BC547. Other components i hope to find in old junk soon.
Something other is going on. I want to use a small table lamp 2-3Watt(6 to 12V) to lit fr USB port . M i right. Has the use port that power. Ofcourse here also i will be using white LEDs.


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## janitha (Aug 25, 2006)

int86 said:
			
		

> Roller,
> some guys r finding this simple idea useful.
> Today i only got BC548. The local guy told me it will work as BC547. Other components i hope to find in old junk soon.
> Something other is going on. I want to use a small table lamp 2-3Watt(6 to 12V) to lit fr USB port . M i right. Has the use port that power. Ofcourse here also i will be using white LEDs.


If I remember correct, 547,548,549 as well as 147,148,149 should work because there is not much difference between them, especially in simple circuits like this.


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## Rollercoaster (Aug 25, 2006)

Dudes.......

*strikethru*
There is a major difference between a 548(aka 148 ) and 547(aka 147). One is NPN and the other is reverse i.e PNP(so some polarities will need to be changed accordingly...). I am not a student of electronics so i cannot provide an correct explanation.
*strikethru*

but what i will do is i will go to my fav radio shack, get stuff and make two circuits with both 548 and 547. I had wanted to do it exact mod long ago but somehow it passed away... 

So wait for tomorrow evening 
__________
@int86
I dont think that using a USB port to light up a bulb is a good idea. Bulbs use quite a bit of power. U can experimetn tho. Max current allowed on a USB port is 150ma I think. But what ever elumination a 6v Bulb can provide it can be done with White LEDs

also, a USB Port provides 5V so the 6v bulb wont be bright. and a torch bulb(3v) will blow...


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## john_the_ultimate (Aug 26, 2006)

Hey rollercoaster.
I want to install a CCFL tube (Blue) in my chassis but was not able to find any. So is there any alternative to this other than using LEDs. I already have few LEDs installed. The ones available from ANTEC r too costly. So pls give ur valuable suggestions, in details if possible as to how to connects, what stuffs r required etc.


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## janitha (Aug 26, 2006)

Rollercoaster said:
			
		

> Dudes.......
> 
> There is a major difference between a 548(aka 148 ) and 547(aka 147). One is NPN and the other is reverse i.e PNP(so some polarities will need to be changed accordingly...). I am not a student of electronics so i cannot provide an correct explanation.
> 
> ...


Again you are wrong. 147,148,149 and 547,548,549 are NPN and 157,158,557,558 etc. are PNP.
I am also not a man of electronics. I am a Forester.


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## Rollercoaster (Aug 26, 2006)

@john the ultimate: well u could go fro those LED tubes. Or if u really interested u can do what i did. Install a Laser Torch inside ur PC with some kool graphics. But mine broke.  anyways it is very simple. just needs a 3v supply.

jainitha@ dude u r technically right. i did check it out.


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## int86 (Aug 26, 2006)

Where to focus laser light.
It is just using a power source and nothing gr8.
Tell me how to read resistor. I know the color coding but not know which way to hold it 4 reading.


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## john_the_ultimate (Aug 26, 2006)

Pardon my ignorance, but what is a Laser Torch? Some picture/sample would be helpful. Also how to install it so that it look like a  illumunated tube.


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## Rollercoaster (Aug 26, 2006)

*www.bcdxc.org/resistor_color_codes.htm
*brunningsoftware.co.uk/ResVal.htm

look at these and google for more.

btw it is raining hard here in dehradun.. so this mod has to wait till tomo for me 


LASER MOD: Just a simple red dot laser wont look good. get one of those laser keychains that come with lens coverings.. put on which ever u like and point it onthe mobo or something. will look good only if u have a transparent side cover.
--------------------
@jhon the ultimate
look at this *www.m-99.co.uk/Electrical/Laser_Pointer_Keyrings/laser_pointer_keyrings.html

in india these are available for less then 150rs in grey markets like chinese or choor bazzar

sample of display patterns:*img170.imageshack.us/img170/8501/patternsanixk9.gif

_____________________

*i think another nice MOD would be to point the laser graphic on to a translucent side cover from inside. would look really amazing. specially if we rig it to blink with the HDD LED  sounds good i will give a thought to this....*


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## int86 (Aug 26, 2006)

Ya great thinking roller. I got a good laser with 15 lens 4 Rs20. It will take a month 4 me to make a side transparent.


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## Rollercoaster (Aug 26, 2006)

are u sure Rs20???? GOD DAMN! That was cheap...

i hope it was not a typo and the real price 200


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## int86 (Aug 27, 2006)

Chinese item has no values.


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## john_the_ultimate (Aug 27, 2006)

Thanks rollercoaster. Will try.....by the way I do have a transparent side cover.....which I made myself.


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## int86 (Aug 27, 2006)

Jhon
how did u made a transparent cover.  I also plan to make one.


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## john_the_ultimate (Aug 28, 2006)

First of all the spelling of my name is "JOHN" and not JHON. Just wanted to clarify.
Now back to business...................about transparent cover just use PLEXIGLASS available at any glass shop.
Then a nice little (as big as u require) window and drill holes for the nut and bolts or u cud just glue it on with say...fevikwik (but I prefered nut and bolts because it is safer and also looks good) and attach the glass. Now u have a see-throught window. Or see this guide *www.aselabs.com/articles.php?id=42
Will post some pictures when I do complete my cabby mod.


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## Rollercoaster (Aug 28, 2006)

alright people. its done.

I tried with both 557 and 547 transisters. works fine with the ckt i have given. Though my LEDs were less brighter with 547 because it was faulty or something.

*Lets take a look at the ckt again*
*img168.imageshack.us/img168/5684/hddleddl0fl3.jpg

One thing to note is that my HDD activity LED was -ve driven. 
*Different mobos can have different polarity driven LEDs.*

The rule of thumb here would be:
*-ve driven:* when the +ve voltage is applied always and the -ve is applied and removed when the LED needs to be turned ON/OFF. *Use BC557*. Connect the point marked with *X* to -ve leg of HDD LED.

*+ve driven:* when the -ve voltage is applied always and the +ve is appled and removed when the LED needs to be turned ON/OFF. *USE BC547*. Connect the point marked with *X* to +ve leg of HDD LED.
__________
For the rest follow my previous post:


			
				Rollercoaster said:
			
		

> *VR1* - VR1 is a preset available for <10Rs. The view shown is the pic is *top view*. It is a variable resistance. Buy one. Connect it using the two pins marked by red dot eitherway. Now before power ON turn the dial on the preset fully to the right with a screw driver. Now power on. If ur LEDS dont glow then start turning the dial to the left slowly and keep turning untill u have max brightness. Stop turning when u have bright enough LEDS. Be Carefull not to turn more if the brightness stops increasing and start turning right now till u see the Brightness start to go down slightly. you are done. Now u are drawing the lowest possible power from the mobo. This circuit is completely safe.
> 
> And hey, do some 3-4GB data copy or run degragmenter to keep the HDD LED ON so that u can see the new added ones to light up.


__________
.
.
PS. John sorry for the spelling mistake 
.
.


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## XtraOrdinary (Aug 30, 2006)

OMG.. 
is this real or what??? has anyone tested it.. my pc wont go BOOM na!

i want to do this like i want to breath.. i did small project in school in electronics.
are these 557 things available?

this forum is hightech man. and i thought only amatures read digit. but i am stumped.

please tell if someone completer it?

rollercoaster- u r the guru. i am amazed at ur effort. what other modding have u made. anything with fans....


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## janitha (Aug 30, 2006)

XtraOrdinary said:
			
		

> OMG..
> is this real or what??? has anyone tested it.. my pc wont go BOOM na!
> 
> i want to do this like i want to breath.. i did small project in school in electronics.
> ...



First let me confess that I have not tried Rollercoaster's circuit due to shortage of time.

But in all possibility it is worth trying and the components are esaily avialable and very cheap.
I really admire him in the attempts.


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## Rollercoaster (Aug 31, 2006)

@xtraordinary: i can assure u that the above circuit works absolutely fine. still as this is elecronics, i will say try at your own risk. For this mod u should have some electronics unerstanding.

@int86: dude where did u go?

@janitha: thanks

@


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## int86 (Aug 31, 2006)

@roller
when u join irc
i was busy in ganesh puja. I got all stuff i have just to solder.


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## Rollercoaster (Sep 2, 2006)

ok guys here is a video of the HDD LED MOD.. sory i dont have a camcoder so will have to do with a very very low res mobile video. use quicktime to view. it is 3g2 format.

LINK (size ~550kb) : *rapidshare.de/files/31649785/LED_MOB_Rollercoaster.3g2.html

Please tell me your comments...


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## Rollercoaster (Sep 4, 2006)

Could use some feedback guys 

not many modders here at digit.


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## blackpearl (Sep 4, 2006)

I m also thinking about lighting up my cabinet using leds. I bought a couple of blue and white LEDs today. I plan to use a 555 in astable mode and connect the o/p to one group of blue LEDs. Then I will use the same o/p and connect it to another 555 in inverter mode and connect another group of white LEDs to the o/p of the 2nd 555 IC. The result will be that the blue and whilt LEDs will glow alternately. I will adjust the clock pulse of the 1st 555 IC to give about 0.8 sec width pulse. Will tell you when its finished.

P.S: My only concern now is upto how many LEDs can the 555 IC drive. I will download the datasheet of 555 first.


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