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Electronics QT11x Question

Discussion in 'Modding' started by Astaroth125, 1 Jun 2005.

  1. Astaroth125

    Astaroth125 What's a Dremel?

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    First of all, I'm borrwing this schematic from Coorz, sicne I'm using that as a reference. If there's a problem, please let me know, and I'll take this down and make my own.

    [​IMG]

    My apologies to Coorz, was being absentminded and didn't think of you're bandwidth, now hosted through me.

    I also apoligize for my newb-ness of the questions, I'm just starting to get this stuff figured out, and want to make sure I understand it. I've spent the past few hours searching the forums and trying to make sure I understand, but I want to make sure I'm understanding it right.

    In this schematic, the electrode is connected to both SNS1 and SNS2, with a .1uF capacitor after the split between the wires for SNS1 & SNS2 but before going into SNS1. Here's a capacitor I believe would work: Link Here

    OUT goes into the motherboard power header (along with a ground), and VDD comes from the +5vSB. Now, OPT1, OPT2, OUT, and VDD are all connected through a wire.

    Am I reading this right?

    Also, would that capacitor be okay to use?

    And, lastly, this is very similar to a diagram I came up with earlier (before I found this schematic) and I was pondering pulling the +5vSB from the PSU. It occured to me, that the two pins on the motherboard power switch header must be +5vSB and a ground/sense pin. When you short them, the ground/sense pin detects the voltages/completes the circuit.

    By that logic, I would run a wire from the +5vSB motherboard power switch header to the VDD input on the QT11x, and run the OUT wire to the ground/sense pin on the motherboard power header.

    I'm ordering the parts for this tonight, I just wanted to perhaps get an educated opinion before I start soldering all this together.

    Thanks for the help and advice in advance.

    Astaroth


    EDIT: Figured a working link to the capacitor might help...
     
    Last edited: 1 Jun 2005
  2. g0th

    g0th What's a Dremel?

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  3. Astaroth125

    Astaroth125 What's a Dremel?

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    Heh, please ignore my misplaced decimal place. :D
    I might order it from Digikey with the QT11's, I was just using radioshack site because I'm familiar with it.

    Out of curiosity, if one pin is sense and one is ground, and on a standard momentary switch, one lead is connected to each pin, where does the voltage come from to trigger the sense wire? I am 99% positive the switch I pulled off this case had 2 connectors, both running to the M/B header, so I would theorize one would have to provide voltage. Also, jumping the headers with a jumper or screwdriver shouldn't work if one doesn't provide voltage. (Keep in mind, this is based off my limited understanding of these components, please correct me if I'm wrong.)

    I'll check the WOL feature on the board.

    Astaroth
     
  4. whypick1

    whypick1 The über-Pick

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    Echoing g0th, RadioShack is such a ripoff, please please please please don't use them again unless it's a life-threatening emergency, and even then don't :D.

    Motherboards kick on by shorting out the two wires that are connected to the switch. One of them is ground, and the other is the sense wire. When the sense wire gets a rising signal (i.e. ground to positive voltage), the power-on circuit latches, which ties the green power-on wire on the ATX connector to ground, turning on the computer.

    All you really need to do is tie the output of the QT110 to the ungrounded pin on the power header. The way coorz setup the QT110, the output will momentarily change from high to low, creating the rising action that the switch does to power on the system. Note, however, that you NEED the QT110, not the QT110H. If you were to do this with the QT110H, you'd have a problem, as holding down the power switch for more than 4 seconds turns off the computer, so you'd have your computer on for a whole 4 seconds before it kicked off. If you can't get the QT110, you can still use the QT110H, you'd just need to setup a regular old NPN transistor as an inverter so that when the QT110H is high, the output of the transistor is low.
     
  5. Astaroth125

    Astaroth125 What's a Dremel?

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    Then I assume I'd pull the 5vSB for the QT110 from the PSU directly? (Perhaps off the ATX connector).

    Also, is this the QT110, not the QT110H? Just wanted to make sure.

    Thanks,
    Astaroth

    P.S. I'll order the capacitor from DigiKey, can anyone recommend a good brand of capacitor?
     
    Last edited: 1 Jun 2005
  6. g0th

    g0th What's a Dremel?

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    From the ATX connector, usually the purple wire, or from somewhere on the motherboard like a WOL/WOM connector
     
  7. Astaroth125

    Astaroth125 What's a Dremel?

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    While I'm at it, I'm planning to use two of these switches, one for power and one for reset, there wouldn't be a problem with that, would there?

    Thanks for all the help,

    Astaroth
     
  8. g0th

    g0th What's a Dremel?

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    Should be fine.
     
  9. Astaroth125

    Astaroth125 What's a Dremel?

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    Thanks for the help, g0th and whypick, I ordered the parts for the switches a few hours ago, the rest of the parts should come tomorrow, so I'll be continuing work on my case tomorrow. I'll post a project log style gallery when I'm done.

    Astaroth
     
  10. Kickn

    Kickn What's a Dremel?

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    I use the QT110 as a touch sensitive power switch and find that the 5VStandby off the PSU/ATX power supply is the best source - and just wire it using the motherboard header power button + and any ground you can find.
     
  11. coorz

    coorz Miffed

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    Is that a wise move to make a touch-sensitve reset button :D
     
  12. Astaroth125

    Astaroth125 What's a Dremel?

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    Not really sure. :p Depends on the sensitivity, hopefully I won't be pawing at my case constantly. Figured for $1.80 I'd try it out. :D

    One question I did have, I was going to study the data sheets to try and figure it out, would I really connect OPT1, OPT2, OUT, and +5vSB together with a wire? Or is it OPT1 tied to OPT2, OUT only to motherboard, and +5vSB only to Vdd?

    Thanks in advance,

    Astaroth
     
  13. coorz

    coorz Miffed

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    opt1, opt2, and Vdd all go to +5Vsb. And err look good; the OUT goes to the mobo power header, NOT 5Vsb.
    Forget about the reset switch, build an eject button, much more fun :)
     
  14. Astaroth125

    Astaroth125 What's a Dremel?

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    Heh, this will be my first dive into anything more complex than adding a resistor, can you tell? :D Got it now.

    Thanks for the help.

    Astaroth
     
  15. One~Zero

    One~Zero What's a Dremel?

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    If you really wanted to get a good idea of how it works, get the demo kit for the QT11x sensor. It comes with a couple of the different sensors in that series, and a premade board to play with. Really cool (already have one) and pretty cheap. They sell those at digikey as well.
     

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