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Thread: Making a TTL laser analogue modulated ?

  1. #11
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    dont worry ill fit u in to my shedule somewhere

    yes i prefur to use a singel driver to although a seperate analog drive wil work just fine
    Do not look into laser with remaining eye
    Need laser repair contact me !!!!!!

  2. #12
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    I know ! I will just wait patiently, no worries, check my other topic about my 150mW green also, i fixed something !

  3. #13
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    I have had a few of these lasers... (Exact model number)

    Did 1 watt for about 10 hours then just got dimmer and dimmer....

    Bought another and got the original one repaired,,, Both did the same again !

    Then I did buy them via Ebay...LOL

  4. #14
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    I have one its analog, those are CNI mine has a 1w cni sticker and puts out 1.3 but yeah those are cni possibly overdriven to hit 1 watt. which is why they wont last...

  5. #15
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    My one did 988mW on a coherent meter (will check this weekend again when i get my LPM from Rob). So i thought " Hey 1000mW -> 988 mW not bad, since it's been used".
    Then i discovered PL and found out that new ones (from respectable companies, not LaserWorlds) output almost more than you pay for... so it probably is very old and has a lot of hours on it,,,, anyway 988 => 150mW so i bought it...

  6. #16
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    Hello everyone,

    I'm building a new ILDA controlled unit which will be used in a laser harp project. The scanners are a CW20K kit from eBay, and the lasers used are 50mW DPSS green, a 300mW 650nm red and a 250mw 405nm blue which will make up some nice white.

    Now, the driver board I got with the 50mW green DPSS is TTL blanking only. I haven't got any data on the module with regards to its current and lasing threshold, I might do some measurements in the future but I would like to use the existing board if possible.

    I was thinking of using a sawtooth generator and comparator circuit to convert the analog blanking on the ILDA connector to a PWM signal and use that for laser blanking. Would that work? If not, do I run the risk of frying my laser because I'm feeding it a pretty high frequency (10kHz) blanking signal? The green DPSS is the most expensive laser in my kit, so I don't like the thought of having to get a spare.

  7. #17
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    PWM would only work if the beam wasn't to be scanned. You will just end up scanning a row of dashes instead of a line.
    http://img62.imageshack.us/img62/3985/laser.gif

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  8. #18
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    Quote Originally Posted by Doc View Post
    PWM would only work if the beam wasn't to be scanned. You will just end up scanning a row of dashes instead of a line.
    That depends on the PWM frequency in relation to the scanning frequency. The base frequency of my sawtooth generator will be around 10-20kHz, which would result in a row of dashes only if you're blanking every other point or so.

    Theoretically, it would look like a row of dashes, but they're going to be tiny.

    Is there any software support for TTL units anyway? Running the laser as-is would be the most useful option for the time being, I'd want to try to convert it to analog but I'm a little concerned with damage.

    On the other hand, I can also pull a spare 200mW red diode from one of my DVD burners, and use that for testing.

  9. #19
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    Lightbulb

    Quote Originally Posted by Stoney3K View Post
    Is there any software support for TTL units anyway?
    I think all software suppot TTL blanking; some of them don't support analog.

  10. #20
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    Cool

    Quote Originally Posted by Stoney3K View Post
    The base frequency of my sawtooth generator will be around 10-20kHz, which would result in a row of dashes only if you're blanking every other point or so.
    The DPSS green laser will probably choke on a 20Khz modulation signal. DPSS designs don't do well with rapid modulation, which is why there aren't more people out there trying to use PWM to get analog-like performance out of a TTL-only unit. It's been tried before, and it just doesn't work.

    You'd be better off trying to replace the driver for the pump diode with something like a flex-mod driver, while leaving the original TEC driver intact. Not an optimal solution, but better than nothing.
    Is there any software support for TTL units anyway?
    Any software that supports analog modulation can be trained to use a laser that only supports TTL. You just won't get anything other than on or off with it, thus you color palette will suffer. But it will work.

    Then too, there are a few packages out there (Alphalite, Full Auto) that only support TTL color.
    I'd want to try to convert it to analog but I'm a little concerned with damage.
    Get in touch with Rob (Stanwax) when you're ready to try the conversion. He's done a few of them, and had considerable success. He can probably offer some very useful advice.

    Adam

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