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Thread: First Flexmod setup help

  1. #1
    Join Date
    Dec 2009
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    London UK
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    Default First Flexmod setup help

    I want to get this right so heres a few questions on setting up a Flexmod2.

    I will be using this on a dual LOC Red setup running them @ 400mah

    Going through the manual...

    1. Power supply, Is this ok? Do you know of anything better/cheaper? (eBay/Paypal) http://cgi.ebay.com/7-5V-DC-40A-350W...item5ad84cb035

    2. Choose modulation range.
    As I need 400mah I need to solder a wire between the Low Pad and the Mod+ Pad. Is this correct?

    3. Adjust the 0 Bias pot until you reach the desired standby current.
    I will be running this using analogue modulation so what do I need to set the standby current at?

    4. Apply 5V to the Mod+ input.
    Does this have to be exactly 5V? and...sorry if this sounds silly but how do I do this? do I take the + lead from the 5v supply and connect it to the mod+ pad/lead and take the - lead from the 5V and connect it to the mod- pad/lead ?

    I understand (I think!) al the bits inbetween these points.

    What do you guys use for insulating laser modules, drivers etc. from the boards? (ebay/paypal links please!)


    Thanks
    Jason

  2. #2
    Join Date
    Oct 2006
    Location
    Cleveland, Ohio
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    2,342

    Default

    Hi Jason,

    1) for a power supply just for the lasers that is outrageously overkill. I used one of these
    http://www.allelectronics.com/make-a...UPPLY/-/1.html
    for may last dual red.

    2) for the low range you solder a jumper from the low pad to the pad next to it that is not the high pad. Don't run a wire all the way to the mod+ through-hole pad.

    3) I'd set the standby current at about 30mA for this diode. That is enough below lasing threshold that the dot will be very dim.

    4) you can use a power supply or your DAC set to full ON (if it is capable of that).

    Included with the FlexMod is hardware that allows you to insulate the output transistor tab from the heatsink mounting point. Many people use thermal pads to insulate the diode casings from the mounts.

    Good Luck! It sounds like you are in very new territory to take it slow and don't follow the mistakes of others (don't short your un-insulated diode mount to the power supply case because your setup is loose on a table)

  3. #3
    Join Date
    Dec 2009
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    London UK
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    Default

    Cheers, I think i'll be ok for most of it now.

    Looking forward to this.

    Lovely little driver btw!

  4. #4
    Join Date
    Dec 2009
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    Default

    Need a little help setting the current.

    I have the low jumper set, I have the power/mod/output leads connected.

    Now first the low setting, I have shorted the mod leads together, at this point on all the previous drivers I have set (LM317 aka DDL drivers) I would place a 1ohm resistor across the output leads, set my multimeter to mV and measure the current across the resistor.

    Can I set this driver like that or do I have to venture my multimeter knob around to the amps setting? I have 10A, 200m, 20m, 200u on the amp side.

    If so how do I measure it (connect the output leads together?) and measure in series?

    Sorry for the nooby questions I just need to do this once and then I it will all be second nature!

  5. #5
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    Hi, either way is fine. Personally on this driver I use the 10A range and put the meter in series in between the + out and - out.

  6. #6
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    OK, I went with my old method of the 1ohm resistor and everything went well.
    Set Bias set @ 30mw

    Now when I applied 5v to the mod input the DMM read a couple of mw under the Bias setting but turning the Gain pot made no difference to the output. it stayed locked @ 28mw?

    Any ideas where I am going wrong?


    Thanks for the help.
    Jason

  7. #7
    Join Date
    Oct 2006
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    A few suggestions..

    Keep the power to the V+ and V- inputs during operation. Some people have mistaken the Mod+ and Mod- inputs as power inputs in the past. That are not, they are only signal inputs.

    Double check your solder bridge on the range setting by re-heating it.

  8. #8
    Join Date
    Dec 2009
    Location
    London UK
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    Default

    Cheers I will check it over.
    Probably the bridge as the power/mod input is ok.

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