I recently got a Fandyfire S3 (1x16340, XML-T6, here) and like it quite a bit except that it always turns on in the next mode. What I mean by this is that it doesn't matter how long the light was off, it doesn't remember the last mode used or always start from the same mode. I can shift from Hi > Med > Lo > Strobe > SOS easily, but if I turn it off in low mode, the next time I turn it on it comes on in Strobe. Am I right in understanding that this is controlled by the driver? If so, can someone explain to me how to find a replacement driver (ie. what specifications do I need to know?) that would either have mode memory or always come on in the same mode? It's the only thing keeping me from loving my first XML light.
What is driver diameter in that light? 16mm, 20mm or something else?
When you find that out, you can search for same-diameter AMC7135-based drivers on KaiDomain (for example), just make sure those are not buck or boost drivers (as with single Li-Ion neither of those would work).
Actually a buck wouldn't behave much differently in action than an AMC7135 based light. Once the cell drops below the Vf needed for the max current of high both will tail off and dim. It's a different way of getting similar results.
People drive boost circuits with single Li-ion all the time too. The 14500 in a AA light that's not designed for Li-ion and ends up brighter is the classic example. Above Vf on the LED the boost is like direct drive (as long as the driver in question doesn't fry passing the power through;) ) Brightness will then drop till cell voltage drops enough to regulate/boost the last chunk of the run. Multilevel drivers that use PWM instead of current control for the lows should still be multilevel; they just modulate the direct drive current making for brighter "lows." Boost with PWM would be my last choice though because I would rather have the diminishing brightness tail from a buck/7135 circuit.
A buck boost circuit is harder to find but is ideal for Li-ion which spends part of the time above and part below Vf for the typical high level. Those are more limited and I can't think of any that rate as budget offhand.
Nice one shadow. Still expensive compared to some of the non-buck/boost budget drivers but budget for it's class. I'll have to look around about the "low voltage protection" because the listing contradicts itself.
Not from Eastern Europe but have spent time there. I word in serbo-croatian that means both battery and flashlight was just too good to pass up as a name.