Page 2 of 2 FirstFirst 12
Results 11 to 13 of 13

Thread: Chinese Galvos

  1. #11
    Join Date
    Jan 2005
    Location
    USA
    Posts
    457

    Default

    The DAC is in the shop. I bew it up. again.

    Soon. very soon.

  2. #12
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,446

    Default

    Spec;

    Glad to meet someone else with a set of these new Chinese DT-40 galvos! I just ordered a set myself. They'll be my first closed-loop set, so I'm understandably a bit nervous about the whole deal, but I've heard a lot of good things about them, and they sure fit my budget! (Cambridge units were out of the question.) I'll be very interested to hear what you have to say about them. Likewise, when I get my set I'll be sure to post comments on their operation...

    As to liteglow's question about the heat, I think there's more to it than that. Galvos want to be at a constant temperature. As the magnets heat up, they can loose efficiency, and at some critical temperature they will be permanently damaged. However, as the magent warms up the strength of the field changes slightly. I seem to recall older galvo setups actually including "heater" strips that wrapped around the galvo housing and switched on and off automatically to maintain the galvo at a constant temperature. I don't remember what that temp was, but it was pretty warm.

    The idea was that when you first switch them on, they are cold and will perform differently than when they're warmed up. So these little "electric blanket" things would heat up the galvo and keep it hot in-between shows so that the magnetic response was always the same. Of course, if you were doing a show then the I-squared-R losses through the coil would be enough to keep them warm.

    I don't know if that's still done these days or not. The galvos that I've seen with the heaters were pretty large compared to, say, a set of 6800's...

    Maybe these units have the large heat sinks on them because it's cheaper to maintain a cool temperature vs a warm one?

    Adam

  3. #13
    Join Date
    Apr 2006
    Location
    Wirral, UK
    Posts
    191

    Default

    Hi Spec, Buffo

    I too am in the DT-40 club.
    They test good :-)

    http://www.die4laser.com/projector/index.htm

    Regards,
    Robin.

Posting Permissions

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