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Simple LED Circut...need help confused

Discussion in 'LEDs and Optoelectronics' started by Rakivic, Jan 22, 2012.

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  1. Rakivic

    Rakivic

    11
    0
    Jan 22, 2012
    I am new here but I thought that someone here could help me with my simple project that has me flustered for over a week now.

    I would like to use a latching vandal switch to control 2X blue led's as well as the LED's on my fan for my upcoming computer build. The problem I have is that I don't know how I would wire it all up. I did a search online and ended up just making my self more confused the I already was. This is what I would like to run from/off the switch:

    2X Koolance dual ultra bright LED's with a single 4-pin Molex connector
    image here(this is my main sticking point I see no resistors in the circuit and wouldn't it blow running of 12 or even 5v?

    1X BitFenix Spectre LED Fan 230mm picture here the fan connector appears to just be a on/of not meant to carry voltage based on the fact if you jump it out the lights come on.

    The switch I plan on using is a Delrin Vandal Resistant Illuminated Switch from performance-pcs. connections diagram here


    Does anyone know how I would wire all that up? I am a computer tech not an electrician lol
     
  2. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    The pictures of the dual LED setup are not detailed enough to say what may be in the wiring splices. There may be a 330Ω 1/8W resistor in one of them
    Any motherboard contacts meant to drive LED's will already have a resistor on the M-b. A lighted fan would also contain a resistor for the purpose.
    It may not be trivial to use one switch to control two LED setups like that, unless you're able to trace the fan LED wires - or measure what they're connected to.
    Also, do you want the light in the switch to be on permanently or only when switched on?
     
  3. Rakivic

    Rakivic

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    0
    Jan 22, 2012
    I want the fans leds to work like a light switch on/off....the wiring is connected to the back of the fan looks like it's simply a switch poll and not meant to carry voltage as it's connected to the same terminal as the 12V molex input for the fan. I cant trace it back any further then that. I will get a picture a post when I return home later today.
     
  4. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    The important thing to find out is which wire is hardwired to which power supply polarity (negative or positive).
     
  5. Rakivic

    Rakivic

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    0
    Jan 22, 2012
    Here is a picture of the back of the fan showing all the connections.

    [​IMG]

    This is the LED wire with the jumper in...when I do this the lights come on with the fan and stay on.

    [​IMG]
     
  6. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    Yes? Which LED fan switch wire is connected to which power wire? I can't tell from the pictures..
     
  7. Raven Luni

    Raven Luni

    798
    8
    Oct 15, 2011
    From the pic, it looks like the LEDs run off 12V (the yellow wire in the PC power connector). My last case was full of these. You should be able to just plug them straight into the PSU without any problems.
     
  8. Rakivic

    Rakivic

    11
    0
    Jan 22, 2012
    I get what your asking me now.

    They are soldered on different contacts.... how ever the negative led wire is on the same circuit path as the red (center) molex wire is soldered to and I think that red wire carries 5V.

    Could be wrong on the voltage carried tho.
     
  9. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    Ok, if the FAN LED - is connected to the red center pin of the 3-pin Molex (which usually carries +12V) then the attached circuit diagram applies.
    If there's only 5V on the center pin for any reason then the two-LED series setup will not work and will need to be altered to a parallel setup.
     

    Attached Files:

  10. Rakivic

    Rakivic

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    0
    Jan 22, 2012
    Thanks if I were to use a regular 2X pole 12V switch would the same diagram apply?

    the leds have resisters build in the wiring I confirmed that by messaging the manuf. My concern is blowing the fan led's
     
  11. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    Yes.

    As long as the fan is made for 12V it should be ok. Each of the 4 LED's in it has its own resistor (I can't read their value through the plastic though).
    If you accidentaly swap the FAN LED + & - nothing bad will happen. The external LED's will then only light independently of the switch position.
     
  12. Rakivic

    Rakivic

    11
    0
    Jan 22, 2012
    I don't want to turn the fan of and on all I need to do is switch off/on the led's the fan is running directly of the power supply....if you connected the 12v line from the switch to the fan would that not blow it tho since it's getting it's voltage from the PSU and the switch wire is taking additional 12V.
     
  13. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    I wasn't referring to turning on & off the fan, but if the fan is made for 12V then so will the LED's be. If it's a 5V fan then the LED's will burn if 12V is applied.
    You connect only the fan to the power, and the switch will draw power from the fan (via the FAN LED contact) and deliver it to all the LED's.
     
  14. Rakivic

    Rakivic

    11
    0
    Jan 22, 2012
    Ok just wanted to be 100% sure, Thanks!
     
  15. Rakivic

    Rakivic

    11
    0
    Jan 22, 2012
    Dident work...

    The switch is connected to 12V directly from the power supply from that the LED's are connected (they have built in resistors) Connecting the fan's LEDs to the 12V switch blew them. They took 24V!! 12v from the fan (it's connected independently to the PSU) and 12V from the switch....only got one fan left to try any more ideas?

    A picture is worth 1000 words so here is what's going on.....it's not a "proper" circuit diagram but you should get what's happening here.
    [​IMG]
     
  16. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    I thought I clearly said that only the fan was supposed to receive power. You didn't wire it according to my diagram, but maybe my 12V reference label confused you.

    You don't get 24V from two +12V outlets, only if you wire in the negative 12V. I don't see how it would be possible to blow the LED's in the fan in any way.

    It's virtually impossible to understand what's going on in your drawing and exactly what happened or not, since the working's in the details.

    I've expanded my diagram to include the fan, and boxed in the parts. Hopefully it's a little easier to understand for a layman now.
     

    Attached Files:

    Last edited: Jan 24, 2012
  17. Rakivic

    Rakivic

    11
    0
    Jan 22, 2012
    I see what's going on now but I am just using a normal 2X pole switch so in that case I would need to omit the resistor going to the switch led correct?
     
  18. Resqueline

    Resqueline

    2,848
    2
    Jul 31, 2009
    The switch LED refers to the one inside the tamper-proof switch. You can of course omit both this LED & its resistor.
    You can connect any other LED (up to 3 in series) in there like that (but it has to have a resistor or else it blows).
    If the fan was made for 5V it would have 100 ohm LED resistors. If 12V is applied to this a current of 80mA will flow (4 x normal) and the LED will soon die.
     
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