dcsimg
Results 1 to 9 of 9

Thread: [RESOLVED] Help with LEDs for power and hard disk access.

  1. #1

    Thread Starter
    Cumbrian Milk's Avatar
    Join Date
    Jan 2007
    Location
    0xDEADBEEF
    Posts
    2,448

    Resolved [RESOLVED] Help with LEDs for power and hard disk access.

    I am building a custom case and I want to use one of these bulgin switches for the power switch. They come in single and dual LED flavours and I would like to use a dual version but I'm a bit unsure if they are compatible with my system panel connectors.

    The literature does not clearly indicate the terminal layout of the dual versions. I think they use a common ground .

    There is circuit a diagram provided...
    Name:  Bulgin switch led circuit.png
Views: 214
Size:  2.8 KB

    My mobo manual does not give much away...
    Name:  system panel diagram.PNG
Views: 238
Size:  12.3 KB
    I understand the voltage is 5v and I won't need an inline resistor in the circuit. Does that sound right?

    Cheers folks.



    EDIT: I did not really ask a question there.

    Is it possible to wire the switch to indicate power and hard drive activity if it does indeed use a common ground?
    Last edited by Milk; Sep 22nd, 2013 at 11:16 AM.
    W o t . S i g

  2. #2
    PowerPoster
    Join Date
    Feb 2006
    Posts
    20,922

    Re: Help with LEDs for power and hard disk access.

    The diagram means you have a bi-polar 2-color LED, or 2 LEDs lashed up to work like one. These need to be driven by a circuit designed for them.

  3. #3

    Thread Starter
    Cumbrian Milk's Avatar
    Join Date
    Jan 2007
    Location
    0xDEADBEEF
    Posts
    2,448

    Re: Help with LEDs for power and hard disk access.

    Appreciated

    In which case I think I will get the single LED version and use a separate indicator for the HDD.

    Can you confirm whether I should use an inline resistor or not. I am led (pun intended) to believe my mobo will sort that out with its black smoke.
    W o t . S i g

  4. #4
    PowerPoster
    Join Date
    Feb 2006
    Posts
    20,922

    Re: Help with LEDs for power and hard disk access.

    You need to look at the voltage of the signal and the type of LED. LEDs vary in voltage by color, it's just how they work. Usually a case LED already incorporates the necessary voltage dropping resistor or a slightly more complicated driver circuit.

    That spec sheet for example mentions which models have a resistor built in and others where you must supply one.

    See Choosing The Resistor To Use With LEDs

  5. #5

    Thread Starter
    Cumbrian Milk's Avatar
    Join Date
    Jan 2007
    Location
    0xDEADBEEF
    Posts
    2,448

    Re: Help with LEDs for power and hard disk access.

    I've been thinking about using the bipolar LEDs again.

    I found an example circuit for driving bipolar LEDs which seems okay here.

    Combining the above with google, the gimp and my lack of electrical knowledge I came up with this...

    Name:  bipolar circuit 2.PNG
Views: 216
Size:  15.4 KB

    which shows the HDD circuit on the left and the PWR circuit on the right.

    Am I on the right lines? I have enough information from the article to work out the resistors.

    W o t . S i g

  6. #6
    PowerPoster
    Join Date
    Feb 2006
    Posts
    20,922

    Re: Help with LEDs for power and hard disk access.

    You might even find such a thing for sale as a driver IC in a small package. Looks about right to me though.

  7. #7
    coder. Lord Orwell's Avatar
    Join Date
    Feb 2001
    Location
    Elberfeld, IN
    Posts
    7,590

    Re: Help with LEDs for power and hard disk access.

    if i were building this, i would use a led with three pins. they allow individual color control but you can still use a simple circuit to control both like this image shows.
    http://www.scienceprog.com/wp-conten...a_inverter.PNG in any case, all you really need is one tri-pin led and two resistors although you would have to be aware that the hard drive color would become the color the led is with both colors turned on. Be also aware that most bi-color leds will only accept positive voltage on one of the two color pins at a time.

  8. #8

    Thread Starter
    Cumbrian Milk's Avatar
    Join Date
    Jan 2007
    Location
    0xDEADBEEF
    Posts
    2,448

    Re: Help with LEDs for power and hard disk access.

    Cheers.

    I've gone and bought the components now for the above bipolar circuit, it is a little over the top for a flashing light but I'm enjoying learning about it.

    I'm using a opto mosfet thingy for the relay. I'll post the result when I get round to sticking it all together.
    W o t . S i g

  9. #9

    Thread Starter
    Cumbrian Milk's Avatar
    Join Date
    Jan 2007
    Location
    0xDEADBEEF
    Posts
    2,448

    Re: Help with LEDs for power and hard disk access.

    Job done.

    Name:  finished circuit sml.jpg
Views: 136
Size:  38.5 KB

    Thanks for the input chaps.
    W o t . S i g

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  



Featured


Click Here to Expand Forum to Full Width