Results 1 to 4 of 4

Thread: RGB laser blocks with a TTL/Analog driver, problems, and safe laser temp

  1. #1
    Join Date
    Nov 2014
    Location
    mid michigan
    Posts
    792

    Default RGB laser blocks with a TTL/Analog driver, problems, and safe laser temp

    Hello
    I don't know if this has been covered so forgive me if this has been talked about.
    I decided to make a projector using a ghostbusters ghost trap lunch box and has very little space inside so I ordered an RGB block from golden star laser and ran into a problem with the included all in one driver that has TTL and Analog modes and well it did not work as expected, I could not get a good color range and the laser was not cutting off the beam when needed so it left trails and poor response so I pulled it and switched to the simpledrive V2500 for each laser and works great so I started digging in to why the stock driver did not work right in analog mode, when i switched quick show and laserOS back to a TTL setting it worked so that got me thinking and looked up the specs of the drivers and found that the bandwidth for the original driver was 30khz while the Simpledrive has a bandwidth of 100khz, I was not expecting such a huge difference and I think that was the problem so I am now wondering if the combo TTL/Analog drivers from china are all like that.
    Has any one else ran into this problem?
    I know for some of the beginning people building projectors from these types of drivers know of this difference as it made a large impact on the quality of the displayed images
    are there combo drivers that have a wider bandwidth? It's nice not wasting as much power in heat for a compact build but if it can't display a parrot correctly "from quickshow" then they seem some what useless unless your just after simple stuff like a beam show or Lumia effects.
    I want to slip in a second question on what most of you guys would consider a safe operating temp range for the lasers, running a complex image i am seeing an internal heat of about 47C and that is with a cooling fan

    Thanks
    Draco
    Polk SDA SRS, Parasound HCA 3500, Luxman M117, Onkyo 504, 7.62X39, sometimes a ball on a string is the greatest of toys for us nonhuman types. oh and some lasers, lots of lasers

  2. #2
    Join Date
    Nov 2014
    Location
    mid michigan
    Posts
    792

    Default

    I still have the question on the laser operating temp, since I don't have the data on the brand/model of the laser it's self I don't want to push it, the diodes seem to be able to take at a max temp of 70C i think i am safe but if i use the sensor on the V2500 that kicks out at 45C

    Thanks Draco
    Polk SDA SRS, Parasound HCA 3500, Luxman M117, Onkyo 504, 7.62X39, sometimes a ball on a string is the greatest of toys for us nonhuman types. oh and some lasers, lots of lasers

  3. #3
    Join Date
    Jan 2006
    Location
    Charleston, SC
    Posts
    2,147,489,091

    Default

    47 degrees C does sound a bit high, but it's well within the acceptable range for a diode. I'm assuming you've got the module mounted on an appropriate heatsink or baseplate, yes?

    I had some 8 watt RGB modules from Goldenstar several years ago that generated an amazing amount of waste heat. I suspect that they had the TECs running wide open, rather than regulating them based on temperature, but if you didn't heat-sink those modules properly they would rapidly overheat and trip out on thermal overload. The cut-off point was around 70 degrees C, and in the early days working with those modules I tripped that overload circuit lots of times. Never damaged any of the diodes though. (The final thermal solution involved a heatsink/baseplate with 2" deep cooling fins and a pair of 24 volt fans on a variable-speed thermal circuit. Managed to keep everything at 40 degrees C or less during a 2-hr stress test with +5 volts DC connected to all 3 modulation inputs.)

    Bottom line, I think you'll be fine at 47 degrees, unless you plan to use it outside in the blazing sun or something.

    Adam

  4. #4
    Join Date
    Nov 2014
    Location
    mid michigan
    Posts
    792

    Default

    Quote Originally Posted by buffo View Post
    47 degrees C does sound a bit high, but it's well within the acceptable range for a diode. I'm assuming you've got the module mounted on an appropriate heatsink or baseplate, yes?

    I had some 8 watt RGB modules from Goldenstar several years ago that generated an amazing amount of waste heat. I suspect that they had the TECs running wide open, rather than regulating them based on temperature, but if you didn't heat-sink those modules properly they would rapidly overheat and trip out on thermal overload. The cut-off point was around 70 degrees C, and in the early days working with those modules I tripped that overload circuit lots of times. Never damaged any of the diodes though. (The final thermal solution involved a heatsink/baseplate with 2" deep cooling fins and a pair of 24 volt fans on a variable-speed thermal circuit. Managed to keep everything at 40 degrees C or less during a 2-hr stress test with +5 volts DC connected to all 3 modulation inputs.)

    Bottom line, I think you'll be fine at 47 degrees, unless you plan to use it outside in the blazing sun or something.

    Adam

    Thanks,
    I have it on a base plate with a heat sink fins under that with a fan, so what I think I may do now is sub the AC supply for the galvo's with two DC-DC converters, that should free up enough space to use a heat sink with longer fins, The DT-40's are on the same base plate so that's more heat.
    I started to have more of a thermal problem when i could not use the OEM driver for the laser block, so 3 analog drivers got me to that temp, but they will start tripping out at i think 42C so I disconnected the NTC for that.
    30khz on the OEM driver's bandwidth and it's impact an an image was a surprise I thought it would have been better since it's an all diode block.
    Polk SDA SRS, Parasound HCA 3500, Luxman M117, Onkyo 504, 7.62X39, sometimes a ball on a string is the greatest of toys for us nonhuman types. oh and some lasers, lots of lasers

Posting Permissions

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