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Thread: Scanner Fans: AC or DC?

  1. #1
    Join Date
    Dec 2006
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    Pflugerville, TX, USA
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    Default Scanner Fans: AC or DC?

    I am in the process of buying fans for my enclosure. I could run them from my laser power supply (5v) or from line voltage. The only downside I can think of to AC fans is that it adds more high voltage components to the scanner, which is a safety issue when messing around in it. Other than the safety issues, are there any pros and cons to AC / DC fans?

  2. #2
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    Charleston, SC
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    Cool

    I used DC fans because the only AC models I could find moved *way* more air than I needed to. A couple 12 volt DC, 80 mm PC case fans are enough for just about any solid state projector up to a watt or two.

    Adam

  3. #3
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    Aug 2008
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    Ohio USA
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    Default

    Im going to use DC fans also, and I found a Nice Backlight LCD with 3 temperature readings and 3 fan controllers, Alarm with time & date......
    Lasers, Lights, Music, Action!

  4. #4
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    Mar 2007
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    Rotorua New Zealand
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    Default

    Just a point on fans..

    Cheap isn't necessarily good in terms of noise..

    I have learn't the hard way that its real easy to make a "noisy" projector.

    When you first start the fan seems such a minor part but later when you start to use it in anger the noise is a pain in the butt.
    The real cheap fans also seem to get noisier in quite a short time.

    Suggest you look at low noise options with good bearings... may cost double the money but well worth it.
    I have to change several of mine already to get the "jetstream" under control.

    Cheers

    Ray
    NZ.

  5. #5
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    Ohio USA
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    Default

    hey pitts, can you post some pics of your fan setup? or anyone that has any nice shots they would like to share...
    Lasers, Lights, Music, Action!

  6. #6
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    Akron, Ohio USA
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    Default

    Ordinary muffin fans might not be the best thing to use in general.

    They work good in certain applications, but, if the air flow on either side of them is restricted, they just spin like a spoked wheel and don't do much good. They can not create a lot of pressure difference, so they can't push or pull air very well.

    Ducted squirrel cage fans or impellers are actually better at pumping air and if they are designed to be quiet, they can be nearly silent. Take a look at one of those old plug-in parlor air organs. You remember those goofy plastic things that sound like a harmonica, with the chord buttons?

    James.

  7. #7
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    Default

    I'm using two 12VDC 80mm fans on the lower left-rear corner set to inhale, and one 80mm fan (slightly higher CFM rating) on the lower right-forward corner set to exhale.

    I hope to find out in a week or two if that's going to be enough, but I'm pretty sure I'll be OK...I hope....because I REALLY hate cutting round circles in sheet metal...
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  8. #8
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    Delaware USA
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    Default

    Nothing like a hole saw.

  9. #9
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    Default

    Quote Originally Posted by ImageLight View Post
    Nothing like a hole saw.
    Yep - that's what I used; still not a lot of fun, though!

    Never realized sheet metal and thin plate aluminim could generate so many frickin' chips!!
    RR

    Metrologic HeNe 3.3mw Modulated laser, 2 Radio Shack motors, and a broken mirror.
    1979.
    Sweet.....

  10. #10
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    Dec 2006
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    Pflugerville, TX, USA
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    Default

    I have decided on using a couple of 60mm AC fans. To have decent DC fans I would have needed to add a extra power supply so AC is simpler.

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