Cabinet Mod . . . . .LED

[int86]

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.

 

[john_the_ultimate]

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

 

[int86]

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.

 

[Rollercoaster]

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.

 

[int86]

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.

 

[Rollercoaster]

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...

 

[int86]

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

 

[samrulez]

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

 

[janitha]

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

No. "also known as"
__________

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/

 

[Rollercoaster]

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.
__________

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!
.
.

 

[int86]

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

 

[janitha]

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

 

[aku]

@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...

 

[int86]

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.

 

[janitha]

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.

 

[Rollercoaster]

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...

 

[john_the_ultimate]

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.

 

[janitha]

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.

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...

.

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.

 

[Rollercoaster]

@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.

 

[int86]

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.