Results 1 to 8 of 8

Thread: GM20 Question

  1. #1
    Join Date
    Dec 2008
    Location
    Chicago, IL
    Posts
    193

    Default GM20 Question

    I'm using a GM20 (Actually a GM20 Clone from OSLS) as a safety shutter. My question is how hot do these normally run under continuos operation? I'm driving it at 12 VDC and it only seems to be drawing .75A but after about 10 minutes the GM20 case gets up to about 150°F.

    Is this normal?

  2. #2
    Join Date
    Jul 2007
    Location
    Knoxville, TN, USA
    Posts
    3,154

    Default

    Try 5 volts - I believe that's what a lot of folks here are using.
    You might need to use a transistor driver circuit, but it will work, and should run cooler.
    RR

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

  3. #3
    Join Date
    Dec 2008
    Location
    Chicago, IL
    Posts
    193

    Default

    Thanks Stuka,

    Sorry I should have said this earlier. I started at 5VDC with a driver but the shaft only rotated about 2 degrees I thought I might have a problem with my circuit but confirmed the same with my bench supply.

    I found the following http://www.onestoplasershop.com/info.htm on OSLS's website which said it required 12-18 VDC. That did give the rotation I expected but it runs hot.


  4. #4
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Drive it with a pull in current and then relax to a holding current. Once pulled in it will stay with much less energy.

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

  5. #5
    Join Date
    Nov 2007
    Location
    Bend Oregon USA
    Posts
    3,350

    Default

    Steve. Get off the freakin computer and rest!
    Pat B

    laserman532 on ebay

    Been there, done that, got the t-shirt & selling it in a garage sale.

  6. #6
    Join Date
    Dec 2008
    Location
    Chicago, IL
    Posts
    193

    Default

    I have a few hours today and will go back to the 5V driver.

    Many thanks.
    Jim

  7. #7
    Join Date
    Jun 2007
    Location
    Lake Geneva, WI.
    Posts
    2,704

  8. #8
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
    Infinitus Excellentia Ion Laser Dominatus
    Join Date
    May 2007
    Location
    A lab with some dripping water on the floor.
    Posts
    9,890

    Default

    Quote Originally Posted by 300EVIL View Post
    Just remember its input requires active pulldown using a resistor or a TTL buffer or inverter, as another PL member found out, and other then that it works great, ie you leave the input floating and it triggers.

    I'm the one who helped the other guy use it.

    Steve
    Qui habet Christos, habet Vitam!
    I should have rented the space under my name for advertising.
    When I still could have...

Posting Permissions

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