Kestrel
Flashaholic
I have a question on an appropriate configuration for the XM-L emitter for my particular application: obtaining a (second) low output level w/ a low-voltage condition upon activation of an inline resistor.
In the past, it has been easy to obtain relatively-low-current configurations which dim considerably under a significantly lower voltage - the Malkoff M60/M61 and the McC2S tailcap being one popular example. I am thinking along the lines of obtaining a low level via a resistored configuration i.e. the SureFire L1/L2 10-ohm tailcaps.
It appears as though the commonly-available XML-appropriate drivers (i.e. which drive the emitter @ 2.8-3.1 amps) will cut out completely below ~2.8 volts or so. This will not work for my application - a SureFire L1 (or L2) with the low output level obtainable via the 10-ohm resistored tailcap.
It would be ideal if I could obtain a buck driver capable of ~3 amps with a operating voltage input range of 0-5 volts, but I doubt that something like this exists. I have even recently exchanged a few e-mails with Gene Malkoff (who is working on his own XM-L dropin driver design), to no avail.
I have read through Nailbender's thread and have the impression that my driver options are slim-to-none. I have tried very hard to review all other applicable recent threads on this, including most if not all XM-L threads currently running on CPF and I feel like I have a reasonable grasp of the strengths and limitations of this emitter.
At this point, I am thinking of giving up on finding a suitable driver configuration and just trying out a DD XM-L configuration. My application will be in a (longer LuxIII) SureFire L1 bored through to accept an AW 17670. I understand that the LiCo 17670 will be discharging at something like ~3C, with correspondingly increased long-term risk and considerably decreased cycle life. (From posts by AW, I understand that the protection circuit in the 17670 will permit currents of ~5A before triggering, so fighting the high-current cutout in that protected cell is not one of my major short-term concerns).
The DD solution will enable a convenient low level with the two-level resistored tailcap in the SF L1, which does not appear to be compatible with any existing high-current driver due to their low-voltage cutouts. Unfortunately runtime on 'high' will be sorely lacking and continuous runs will not be possible due to excessive heat generation. Furthermore, this solution would essentially prohibit a usable 2xCR123 backup configuration.
Any suggestions as to how to use an XM-L @ ~3 amps with a single 17670 and obtaining a low level via the L1's 10-ohm resistored tailcap would be most helpful. Trying to come up with a good solution to this has taken a considerable amount of time, although it has been an interesting topic to think about.
Thank you,
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Edit: Replies lost due to the crash. Thanks CPF. :-/
In the past, it has been easy to obtain relatively-low-current configurations which dim considerably under a significantly lower voltage - the Malkoff M60/M61 and the McC2S tailcap being one popular example. I am thinking along the lines of obtaining a low level via a resistored configuration i.e. the SureFire L1/L2 10-ohm tailcaps.
It appears as though the commonly-available XML-appropriate drivers (i.e. which drive the emitter @ 2.8-3.1 amps) will cut out completely below ~2.8 volts or so. This will not work for my application - a SureFire L1 (or L2) with the low output level obtainable via the 10-ohm resistored tailcap.
It would be ideal if I could obtain a buck driver capable of ~3 amps with a operating voltage input range of 0-5 volts, but I doubt that something like this exists. I have even recently exchanged a few e-mails with Gene Malkoff (who is working on his own XM-L dropin driver design), to no avail.
I have read through Nailbender's thread and have the impression that my driver options are slim-to-none. I have tried very hard to review all other applicable recent threads on this, including most if not all XM-L threads currently running on CPF and I feel like I have a reasonable grasp of the strengths and limitations of this emitter.
At this point, I am thinking of giving up on finding a suitable driver configuration and just trying out a DD XM-L configuration. My application will be in a (longer LuxIII) SureFire L1 bored through to accept an AW 17670. I understand that the LiCo 17670 will be discharging at something like ~3C, with correspondingly increased long-term risk and considerably decreased cycle life. (From posts by AW, I understand that the protection circuit in the 17670 will permit currents of ~5A before triggering, so fighting the high-current cutout in that protected cell is not one of my major short-term concerns).
The DD solution will enable a convenient low level with the two-level resistored tailcap in the SF L1, which does not appear to be compatible with any existing high-current driver due to their low-voltage cutouts. Unfortunately runtime on 'high' will be sorely lacking and continuous runs will not be possible due to excessive heat generation. Furthermore, this solution would essentially prohibit a usable 2xCR123 backup configuration.
Any suggestions as to how to use an XM-L @ ~3 amps with a single 17670 and obtaining a low level via the L1's 10-ohm resistored tailcap would be most helpful. Trying to come up with a good solution to this has taken a considerable amount of time, although it has been an interesting topic to think about.
Thank you,
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Edit: Replies lost due to the crash. Thanks CPF. :-/
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