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Thread: maXYZmodules 150mW red module

  1. #11
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    Have you considered a closed loop TEC driver circuit? All it needs is
    literally a PIC, a thermsistor and the peltier element off a transistor.
    You PWM the peltier based on the what the thermistor (configured
    as a voltage bridge) returns on the AD input pin of the PIC...

    You should get zero condensation if you avoid "supercooling" the
    peltier. The rule of thumb is 4-6 degrees celsius below ambient
    is the max allowable threshold at 70% humidity. I'd personally
    lock the circuit to maintain ambient. Of course at more reasonable
    50% humidity you can go as far as 15 degrees below ambient.

    Also they sell "vapor barriers" for houses which might work
    for sealing your units in. It's basically a fabric that lets moisture
    only travel one way. It'd be cheaper than worrying about nitrogen fills.

  2. #12
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    Hi Yadda,
    Actually I have been looking at PICs
    I do like that Idea...
    I have worked with PICs in the past
    so,..maybe I'll do some searching for a good one.

    One circuit I have devised is a "bang-bang" PWM
    since we only need to go in one direction ..
    but it is somewhat combersome to use..
    It is a few op-amps and a MAX 1968 and a FET.
    Unless you already have a source for the program for the PIC
    that would be great

    It really needs to be small to fit in the module we use now...
    as there is not much room...however.
    I am about to combine a couple of diodes in my next
    experiment..
    And that will be in a different mount.

    Yes, keeping it just below ambient works ok..
    There is a need...Like -- Holography
    where the wavelength must be extremely stable.

    What we were wanting to do for the lasershow modules is---
    drop the temp way on down, and get the wavelength way down as well..
    It is very dificult to do without damage to the diodes..
    I have tried multiple times , Tests done on a SDL-820 controller
    show to make any real difference in brightness at least to my eyes
    it must go down at least to 10degress c ..from 30c
    this is the area where condensation starts to form
    no matter what you do..
    So, with that in mind we must enclose the whole assembly.

    I have talked to many engineers who have also been where I am at.
    And they agree.
    So, I've got some work ahead of me....

    There are a lot of days we get 90 percent humidity down here...argh.

    *^_^*
    "My signature has been taken, so Insert another here"
    http://repairfaq.ece.drexel.edu/sam/laserfaq.htm
    *^_^* aka PhiloUHF

  3. #13
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    I need a red laser right away, please PM with a quote for one of these units.. With blanking.. Thanks...

    I have not see them on ebay in a while..

  4. #14
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    Hi JayDC

    PM sent

    *^_^*
    "My signature has been taken, so Insert another here"
    http://repairfaq.ece.drexel.edu/sam/laserfaq.htm
    *^_^* aka PhiloUHF

  5. #15
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    thanks, and btw.. the TTL line is (0-5 VDC) correct, or is it (5-0 VDC)?

  6. #16
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    Hi JayDC

    Yes , It is ~ about +5 volts to (blank) or (off)
    (actually a litte over a volt turns it off)
    ~0 volts or nothing for (on)

    I guess you could call it "Inverted blanking"
    At least on my "Alpha" I have to use it that way...
    All our lasers use Inverted blanking because it is more universal that way!!
    Most peeps add another stage which reverses this ...
    Like the circuit Yadda came up with,,which also makes up for
    the different drive requirements by all the control boards out there!!

    If you need any help when you get to that stage of the game,,shout
    we'll help

    *^_^*
    "My signature has been taken, so Insert another here"
    http://repairfaq.ece.drexel.edu/sam/laserfaq.htm
    *^_^* aka PhiloUHF

  7. #17
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    Just got the laser today!.. Looks great, I powered it up, and it's nicely bright in the day time!.. Tonight I'll mount it into the projector, and mix it with green.

    2 things, is there anyway to adjust the power under the hood, and is it possible to focus the beam down a little more?..

  8. #18
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    Hiya jayDC

    So glad it got there for the weekend...

    And glad your happy with it too...

    Sorry, No under the hood adjustments...
    We had to make them this way so that they would last..

    As you know by now, They are extremely stable..
    The key to that is in the design of the diode driver circuit!!!
    The circuit senses the temperature and adjusts accordingly..
    It needs the room "power-wise" to do its job..

    Yeah , We could have made them to put out to the "Max"
    but the stability would suffer as well as lifetime.

    To make beam adjustments , you must use the focussing ring.
    this will make the beam size changes...
    Or , You may like to experiment with anamorphic prisms
    They will change the beam shape to a degree or two..

    If You want to get extreme with the lens experimentation..
    See thorlabs ..Look at the Aspheric lens selection they have...
    It is quite extensive...and Expensive..

    These are the lenses we use...THORLABS
    http://www.thorlabs.com/Nav.cfm?Guid...&Visual_ID=659

    You may try a few of the plastic ones these are cheap ..
    First---while figuring it all out ..
    Then after you get it figured out ...go for the glass
    I would get the glass as they will stand-up to cleaning...
    But your looking at 46 to 82 dollars for one..
    They have less speckle too...

    Just PM me for details if you need help here.

    ^*_^*
    "My signature has been taken, so Insert another here"
    http://repairfaq.ece.drexel.edu/sam/laserfaq.htm
    *^_^* aka PhiloUHF

  9. #19
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    So... how much to get one of those new red's with those lenses?

    Ivan left here drooling over the modules... they look way cuter in
    person than they do in the photos.

  10. #20
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    Hi Yadda,,

    It would add about 100.00 to each module...
    They really start to look "too expensive" that way and most
    dont understand why...

    This until we can find another suitable source for a nice lens..,Cheaper

    We are about to order some more of the Thorlabs glass ones to have around for those who want them.....WE really like them.
    The ones we chose are a direct replacement for the Thorlabs plastic ones.
    With a bit less speckle...lightly better beam profile.
    Sorry ..the line will still be there..its the diode's fault...

    They are a bit tricky to change as you might have to destroy the old
    lens first getting it out without breaking or damage (they are pressed in),.

    So , If you want a Thorlabs Glass Lens upgrade..send us back your laser
    We will send it back with a NEW THORLABS GLASS lens with new thread tape on the threads....SWEET

    These are nice lenses and will we increase the power a little bit too

    *^_^*
    "My signature has been taken, so Insert another here"
    http://repairfaq.ece.drexel.edu/sam/laserfaq.htm
    *^_^* aka PhiloUHF

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