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Thread: Cheap 473nM

  1. #21
    Join Date
    Jun 2006
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    Charlotte, NC
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    1,125

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    My CNI 50mw outputs 68mw on startup and 75mw after 10min warm up. It came with ir filter

    Quote Originally Posted by JimBo
    No problem mate
    I'm just really disappointed with the 50mW that I got from CNI, itwas showing >180mW but it didn't have the IR filter on it.
    They sent me one and now it is showing 38mW
    They are refunding me some of the money though.

    Jim

  2. #22
    Join Date
    Jan 2007
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    142

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    Quote Originally Posted by Spec
    Aijii: These power supplies are "newer/updated". I bitched for a long time about modulation depth/recovery issues and apparently they listened. The board is denser(component) wise than the ones I received a few months ago and a simple oscilloscope test confirms the circuit is a lot snappier with recovery, output when feeding a 0-5v square wave @ 30khz is marginally higher and there appears to be far less ringing in the circuit.

    Granted, its a far-far cry from Marconi's amazing diode modulation system or any AOM but anything is better than the crap we have been fed in recent years.

    But these mods which you speak of: I would love a copy. Seriously.

    Litease: Yes you should. If you are catering to the laserist arena you best be sure 2 things meet their specifications: Rated output in the desired frequency, not useless IR and that the modulation circuit lives up to whatever claims are being made. To Laserists who make their living with these things: almost everything else is trivial. Think of it as Function over form.

    There are a few ways to test that are trivial, a *real* signal generator and a fast oscilloscope with cursors/memory for one. But what I am interested in is controlling the thermal envelope in the optical cavity to make whatever modulation circuit used actually work.

    *FAST* TEC control per crystal, better TEC's on diodes with proper feedback(optical and thermal). All of this is within the realm of technical ability, its just more expensive. Though I would venture a guess and say it is quite cheaper than the cost of the diode and crystals you are trying to control/protect.

    Yes, this is a complex design, but I ask you this: Would you accept a car from a manufacturer that only turned left and had inflated gas economy ratings?

    Food for thought.
    Hi guys laserists and hobbiests! Nice to see you!

    I am David. May i interrupt to say something about modulation on the blue lasers? We have received complanations on the mod. issue. We test with signal generator and oscilloscope. When we test the green lasers, we got a smooth curve close to the input 0-5V 10khz. We can do 30khz though the brightness comes down. But when it comes to the blue lasers, combined to the smooth curve is small curves, so the curve looks like saw-teeth. :cry: You know Lasever uses only one TEC in the laser to control the diode and crystal as a whole. So we also think it is the cause. You know the famous manufacturer in China uses two TEC's. We test it. The result is worse, also saw-teeth. If we draw a curve through the middle of the saw-teeth, Lasever gets a curve similar to the input but the other gets a sharp peak. Maybe it happens to a failure laser. Will who used their lasers esp. the blue to share us your experiences?

    This is Blue Problem :evil: We now find the reason, but it is a huge task to make the modulation of the blue same to that of the green. :roll: In fact only AOM can make it. But you use the lasers. You know what is important for laser projectoer, what can be ignored.

    Thank you everyone to provide comments and suggestions to push or kick Lasever ahead!

    David

  3. #23
    Join Date
    Oct 2005
    Location
    Melbourne, Australia
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    678

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    David,

    Thanks for replying. The modulation issues we have experienced with our own Lasever blue (200mw) definetly CANNOT be ignored!!!

    I apologise, but people (both our customers, and others) are spending a lot of money on these lasers and are expecting them to perform within the specifications that you publish.

    Your explanation definetly does not explain why, on our Lasever blue, we notice the following:

    - when scanning a pattern that is hardly blanked, we notice that half of the "blue" dissappears, and re-appears, every few seconds. This co-incides with a red light on the PSU illumating, when the blue parts of the image dissappear.

    Why is this behaviour not constant ? It appears as though the PSU is "switching" into some sort of mode whereby you heavily filter the modulation, causing this to occur, and it means our RGB laser cannot be used for graphics, because it is not acceptable in our culture to provide customers "half" of a lasershow... (if this explanation doesn't make sense, i can take a video of it...)
    Now proudly stocking and offering the best deals on laser-wave

    www.lasershowparts.com
    http://stores.ebay.com.au/Lasershow-Parts

  4. #24
    Join Date
    Jan 2005
    Location
    USA
    Posts
    457

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    The red light is supposedly thermal, but that rarely triggers correctly.

    Check for a floating ground and run an ohm meter on the laser housing and the shell of the power supply.

    Ive been able to blank a lasever unit by shorting the housing to the power supply housing, or shorting two lasever heads together with an ohmmeter. Not good.

    If you haven't setup isolated grounds and electrically isolated the individual lasers: do it now. It's good practice and will save you some serious headaches in the future.

  5. #25
    Join Date
    Jan 2007
    Posts
    142

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    Quote Originally Posted by aijii
    David,

    Thanks for replying. The modulation issues we have experienced with our own Lasever blue (200mw) definetly CANNOT be ignored!!!

    I apologise, but people (both our customers, and others) are spending a lot of money on these lasers and are expecting them to perform within the specifications that you publish.

    Your explanation definetly does not explain why, on our Lasever blue, we notice the following:

    - when scanning a pattern that is hardly blanked, we notice that half of the "blue" dissappears, and re-appears, every few seconds. This co-incides with a red light on the PSU illumating, when the blue parts of the image dissappear.

    Why is this behaviour not constant ? It appears as though the PSU is "switching" into some sort of mode whereby you heavily filter the modulation, causing this to occur, and it means our RGB laser cannot be used for graphics, because it is not acceptable in our culture to provide customers "half" of a lasershow... (if this explanation doesn't make sense, i can take a video of it...)
    Hello,
    I sent you an email about your problem. The problem can be corrected by adjusting one pot. The red led is designed for overhot protect. Once the red led turns on, the laser turns off. It is not the modulation issue i discuss here. The Blue Problem appears to be: you got say 100mW by input 3V, but you got 70mW by 3.5V; then 120mW by 4V, 90mW by 4.5V...saw-teeth like this. I will post the ossciliscope graphic to show it. But it seems you didnot notice this issue.


    David

  6. #26
    Join Date
    Aug 2006
    Location
    North West England
    Posts
    1,148

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    Dream Beamz,
    How much did you pay for yours and where from?
    My first CNI 50mW blue came from Extremelasers and certainly looked brighter than this one, it also had an IR filter, I didn't have a lasercheck to test it before I killed it though.

    Lasever Dave,
    How much are your blueys?

    Jim

  7. #27
    Join Date
    Oct 2005
    Location
    Melbourne, Australia
    Posts
    678

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    Quote Originally Posted by Lasever
    Hello,
    I sent you an email about your problem. The problem can be corrected by adjusting one pot. The red led is designed for overhot protect. Once the red led turns on, the laser turns off. It is not the modulation issue i discuss here. The Blue Problem appears to be: you got say 100mW by input 3V, but you got 70mW by 3.5V; then 120mW by 4V, 90mW by 4.5V...saw-teeth like this. I will post the ossciliscope graphic to show it. But it seems you didnot notice this issue.


    David
    Thanks for that.

    Which pot is it ? Can you post a picture please ? And what should we be careful of when adjusting ?

    We haven't noticed non-linear issue, because of the "thermal" issue. Ie, if the laser is cutting out for half of a lasershow frame, then thats going to get our attention over any other issues

    I will adjust the pot soon, and report to everyone here with my results.
    Now proudly stocking and offering the best deals on laser-wave

    www.lasershowparts.com
    http://stores.ebay.com.au/Lasershow-Parts

  8. #28
    Join Date
    May 2006
    Location
    Native Floridian
    Posts
    3,127

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    Lasever wrote:

    Hello,
    I sent you an email about your problem. The problem can be corrected by adjusting one pot. The red led is designed for overhot protect. Once the red led turns on, the laser turns off. It is not the modulation issue i discuss here. The Blue Problem appears to be: you got say 100mW by input 3V, but you got 70mW by 3.5V; then 120mW by 4V, 90mW by 4.5V...saw-teeth like this. I will post the ossciliscope graphic to show it. But it seems you didnot notice this issue.


    David


    Thanks for that. Which pot is it ? And what should we be careful of when adjusting ?

    We haven't noticed that issue, because of the "thermal" issue. Ie, if the laser is cutting out for half of a lasershow frame, then thats going to get our attention over any other issues

    I will adjust the pot soon, and report to everyone here with my results.
    I originally had an issue when my 3 lasever units were mounted to the same plate and using the supplied switching power supplies, quite often they would go to no output and the red light would be on a for a few seconds. I solved this by changing over to a single 5V 20amp supply that I use to run the 3 lasers, shutter and some support circuitry. So far, I have not had the red light come on since. All 3 seem quite stable after a good 10-15 minute warm up. The red doesn't really seem to need much of a warmup, it is usually quite stable from the beginning. The green needs a few minutes and the blue seems to need the most time. When running a show the blue seems to be maybe 75% of full brightness during the first few minutes, then after that it looks great. Kinda hard to notice any type of stability issues when a show is running anyway...


    David

  9. #29
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    Oct 2005
    Location
    Melbourne, Australia
    Posts
    678

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    Lasever:

    So which pot do we adjust ? what is the "adjustment" procedure for adjusting this pot ? I am still awaiting your reply...
    Now proudly stocking and offering the best deals on laser-wave

    www.lasershowparts.com
    http://stores.ebay.com.au/Lasershow-Parts

  10. #30
    Join Date
    Jan 2007
    Location
    Florida
    Posts
    4,382

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    Spec,
    Do you sell any 50-75mW blue 473nm from time to time? Funds are low now but I will be looking for one in a few months...
    Thanx
    Steve

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