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Thread: need help with ttl laser driver

  1. #1
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    Default need help with ttl laser driver

    hi im new at this and i have a ttl laser driver that i would like to learn about and posibly use. it has vcc power + and a ground wich i have conected 3vdc to.at the other end there is a ld + and a ld - wich is where im putting my diode or at this point my voltmeter.(the voltage is 3vdc at this point like the whole thing aint even there. and i havnt been able to figured out how to use the modulation wich is to be 0 vdc = off and 2.5 vdc = on. this is what im after, i want the laser off till it reaches 2.5 volts dc on that modulation input. can any one help me? i sure am missing something i hope i have added the pic right. it is a two sided pcb and the pic is showing both sides
    Attached Thumbnails Attached Thumbnails ttl laser driver.jpg  


  2. #2
    mixedgas's Avatar
    mixedgas is offline Creaky Old Award Winning Bastard Technologist
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    [QUOTE=mixedgas;172983]First question, What kind/type of diode do you wish to use with it?

    Keep in mind its mission is to provide a constant current when the TTL input is high, and a low or zero current output when the TTL input is low. laser Diodes, are current driven devices, if you place a battery across them without current limiting, the diode will, in most cases, fry itself. The driver is thus a current limiter. We need to know what type of diode you are using, so we can help you set the correct current.

    There will almost always be a voltage at the output, it is, however, the amount of current that counts.

    Second,
    Does your voltmeter have a way of measuring current?

    We need to set the current before you do this, but if you connect the TTL input to the + side of your 3 volts, the driver will switch on, in most cases. There are some other things on the checklist, such as making sure the diode is heat sinked first.



    Third, are there files on line some place for this driver?

    Also, where are you located? PL members tend to help each other out in person.


    Steve
    Attached Thumbnails Attached Thumbnails Mysterydriver.bmp  

    Last edited by mixedgas; 11-26-2010 at 17:56.

  3. #3
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    i have a 445 blue laser that im trying to use with my setup that uses a sound dac that has a allways on voltage of about 1.9vdc and it has i believe the flexmod3 driver on it.(analouge)and i need the laser to turn off at under a voltage like 2.5 vdc and on at a voltage of over 2.5 vdc. i know this can be done cuz i have a green laser that does this at 1.0 vdc. i bought this laser by mistake not knowing it was wrong kind of modulation for me but now im thinking of putting this driver in front of or onto the modulation of the flexmod.i probly way off base with that. if i have to get another diode then ok but i want to know im on a line of reasoning that might work
    my multimeter has a 25ma scale and a 250ma scale if that measures current.

    can i test with a laser pointer that they sell for 2.99 to play with the cat?

    thanx for the replay its a great help

  4. #4
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    Jul 2010
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    Default its an aixiz lasers driver

    not really any more info about it than what you see in the pic i put up but its from aixiz lasers and i found it under accesories. i am also in porland oregon usa. just to tell ya more about my system,...the sound dac is a usb 6 channel with channels 1and 2 running the scanners and they are in the front speaker output in the dac. and then channel 3 is the red laser that just runs of the sound card voltage(two wires + and -)the slider for that channel increases and decreases voltage from about 3.6 all up to 1.9 all down. the red laser turns on and off at 3.0vdc. the dac will fluctuate the voltage a little and this creates the blanking and color.then i have a green laser that works the same way but it uses too much power for the sound card to supply so it has its own power input of 3 to 5vdc and two wires for the sound dac channel to go to.the laser turns on at over 1.0 vdc and off at under 1.0vdc. i have used switching diodes (radio shack 4148) to get the voltage down to the right voltage to get the laser to blank and color correctly. the thing works perfectly to this point...........my blue is a 445nm 400mw laser with i believe a flexmod3 driver and its 0vdc off and analouge to 5vdc full on. so my sound dac turns it on to about 3/4 power and it never blanks. my question is can i get that laser and driver to do what i need? or should i save it for a futer build? if i cant use what i have then what am i looking for in a blue laser.

  5. #5
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    Feb 2010
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    Here's how they work,in my experience.
    Most info on them is incorrect,,,

    THIS hookup works great for me,,,

    With an input of 3v it will NOT give advertised output of 500ma.
    0v ttl input is laser off.
    Tie +input thru any resistor to ttl/mod and it will work.
    Using 6v in I run a long die open can LPC-815 diode at 390ma @277mw reliably with minimal heat from driver or diode for intermittent use-1min. on etc.
    Turning the trimpot clockwise increases current out.
    I have built and sold a few of these and are still going.
    Mike

  6. #6
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    Jul 2010
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    thank you guys so much! the pic that mixed gas drew for me made that driver work on the front end of the blue laser! i just love you guys for what you do.....i would not have got it on my own.
    the diode was and maybe is a little dim cuz the analog driver is only getting 2.5 volts rather than 5.0 but i took hd58phd's idea and turned up the gain on that and it seems a little brighter to me.(i just hope to remember to turn it back befor applying full voltage again).
    anyway i now have a working laser projector as far as the electronics,mirrors,and lasers goes and now i can build my enclosure.

    Thanks Again
    numpskulls

    i cant wait to build my own now

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