Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 26

Thread: Lasever

  1. #11
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Cool Replacement laser is here!

    Well, I normally wouldn't reply to my own post, but this news merits it...

    My replacement laser from Lasever arrived today! (sounds of cheering)

    I unpacked it and immediately hooked it up. Oh no! Divergence is awfull. Spot on the wall just 15 feet away is larger than an inch in diameter! (sounds of crying and gnashing of teeth...)

    But wait! the lens on the front is adjustable. (yeah, he sent me another MR series head, not the U series head that he originally said he would be sending.) So I carefully adjust the forward lens, and after about 3 full turns the divergence is back to a more reasonable level. (sounds of cheering again)

    So it looks like Lasever wasn't out to scam me - they were just busy and forgot to send the laser. I will of course do a detailed set of tests on this new laser before I install it in my projector, though those tests will have to wait until I have some more free time. Maybe later this week. I'll keep you posted.

    Adam

  2. #12
    Join Date
    Oct 2006
    Location
    Central Florida
    Posts
    7,067

    Thumbs up

    Awesome Adam. It is always a good day when you get a laser in the mail. Lookin forward to your results. A shame about not getting the U series.

  3. #13
    Join Date
    Feb 2005
    Location
    Switzerland
    Posts
    1,410

    Default

    Good news Now we are just waiting on an sign of life from David...

    About the MR heads, I think the thermal mass is not a problem if you attach them to a big enough heatsink. My lasers never get warm even after long time of full power.
    But the TEC itself can be not enough powerful to properly cool the diode (due to its small size, I think max 20x20mm). For example at my work, we have a laser which use a 12W 808nm pump diode. There is 2x 40mm TEC side by side to cool the diode, and a veeery big heatsink (100x100x120mm) with a big fan to remove the heat from the TEC (but ok it's a 12W diode, not a 2-3W like in the Lasever, but it's to give an idea).

    Another problem is the one-TEC design : the crystal get the heat necessary to its correct operation from the diode, instead having a TEC which warm it. So its exact temperature cannot be controlled. But this cannot cause a failure, just instability and not the best efficiency.
    But now, maybe the diode isn't enough cooled (intentionally) to get enough heat to the crystals...

    Anyway, if David comes back here it will be positive, because we can try to help him to figure out the problem (some german laserfreaks are already working with him if I understand well)...

  4. #14
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Smile

    Aaron;

    Once again you have proved that you are the king of the smileys! And actually I don't mind getting the MR head vs the larger U series head. So long as the laser works I'm happy.

    SBK:

    My old MR head (the one that failed) never even got warm to the touch, much less hot. It was mounted on an aluminum base plate the entire time.

    The idea of using just one TEC for the entire head (rather than having two separate TEC's, one for the diode and one for the crystal) may be part of the problem, but I haven't been able to prove that they are ini fact only using a single TEC. (Looking at the driver board seems to suggest that they are, but I'm not certain.) Either way though, it's good to know that folks on the laserfreak forum are also aware of the issues and are working to help solve them.

    Adam

  5. #15
    Join Date
    Feb 2005
    Location
    Switzerland
    Posts
    1,410

    Default

    If they were using 2 TEC, they would be 2 connections pair of "+ and - TEC" and "thermistor" on the connector, not? And I see only one pair
    But I think it's not the problem. A one-TEC design is used for almost all 532nm DPSS modules below a certain output power (I think <400mW) and it works without problems... But now, crystals used to generate 473nm are more sensitive to temperature for sure.

    Sebastien

  6. #16
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Cool

    Hi Sebastien;

    The lasever MR series head uses a 9-pin connection to link the head to the driver. So if you use a common ground for the TEC's you can run two of them, plus thermistor leads, plus the leads to the pump diode itself, and not run out of connections.

    The reason people think there is only one TEC is because of the arrangement of the adjustment potentiometers on the driver board. The diode drive circuit has an absolute limit pot and a current setpoint pot. Assuming the TEC circuit has the same thing, then if there are two TEC's there should be 6 total pots. (2 for the diode, and 4 for the TECs.) But the driver board only has 4 pots. We know that two of them are for the diode, so that leaves just two for the TEC(s). In theory you can run a DPSS blue with just one TEC, but everyone I've talked to about it has said that it's an engineering nightmare. Much better off using two separate TECs. (As you mentioned, 473 nm is a lot more tricky than 532 nm.)

    Adam

  7. #17
    Join Date
    Jan 2007
    Posts
    142

    Default Greetings from Lasever

    Hello friends on the Forum!
    First I appologize for the troubles our lasers brought to you! The reason is now mostly cleared. Lasever treasures the reputation in the industry. We will return lasers to you in two to three weeks.
    Thank you all for criticizing and supervising us!
    David
    Professional manufacturer for High Power DPSS and Diode Lasers.
    1~8W 638nm Red
    1~8W 520nm Green
    1~20W 445/465nm Blue
    3~10W RGB laser
    http://www.lasever.com/
    Email: sales@lasever.com

  8. #18
    Join Date
    Feb 2005
    Location
    Switzerland
    Posts
    1,410

    Default

    Hello David,

    Nice to know that you are alive
    And nice too that you find the reason of the failures. I hope Lasever will return to the quality level to which we were accustomed.

    Sebastien

  9. #19
    Join Date
    Jul 2005
    Location
    Flying over a town near you
    Posts
    1,404

    Default

    Somehow I knew that he would come through. This is what makes a good business.
    You are the only one that can make your dreams come true....and the only one that can stop them...A.M. Dietrich

  10. #20
    Join Date
    Feb 2005
    Location
    Switzerland
    Posts
    1,410

    Default

    He comes back just after I sent him a mail with a link to this thread
    But he didn't answer me personaly by mail, so I didn't know how to do with my defective laser

Posting Permissions

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