Techjunkie
Enlightened
I've been modding a lot of lights with XM-L emitters lately. This is one that I've prepared to receive an XM-L, but as I ran out of them, it for the moment has a de-domed SST-50 in it. I've never had a flood to throw light before 'cause I thought they were kinda hokey, but I think this one is really unique and kind of impressive.
I started the receipie looking for the most compact flood to throw light that I could fit an IMR 22650 in. (Not 26650, but 22650). The SacredFire NF-08 was perfect. Same size lens as almost all other flood to throw lights, but no wasted space in the bezel diameter. The whole light has the same diameter from head to tail which really appealed to me for keeping in the coat pocket. The tube, intended for 3AAA carrier is not much fatter than 18650 flood to throw lights, which despite having narrower tubes, for some reason mostly have larger heads when the same lens is used.
The second ingrediant obviously is the LiMn 22650 battery, which was the inspiration for the project. I wanted to be able to run an XM-L to the edge and stay in regulation for as long as possible. The extra capacity gives the light the power headroom I wanted without dramatically increasing the size like a 26650 or 26500 cell would.
Here's a pic of the light next to this oddball battery on the charger:
From the front, you can see the de-domed SST-50 LED with phosphor damage in two of the corners:
You might notice the tail boot is kind of pointy. To handle the current and provide forward action, I replaced the stock switch with a KD fwd click switch. There wasn't much boot stub to cut out to make room for the taller plunger, so the boot now protrudes a bit more than before. No biggie.
The final and most complicated ingredient was a driver sandwich. For the base, I'm using a 17mm multimode 8*7135 board that lets you select the modes available by soldering stars on the ground ring. (I got this one from KD, but I think ShiningBeam has the same or similar item.) For the available modes, I chose Hi-lo-strobe. In EDC lights, I like to have the strobe handy to point at the ground to get drivers attention if necessary while crossing an unlit street at night.
Two 15mm 3*7135 boards are slaved from it for a total of 4.8A regulated output in hi mode. It was a real challenge getting everything to fit in the pill, and I used the wires supplied with the 2.8A board instead of my usual 20 awg copper. I think they might account for additional resistance causing hi mode to top out at 4.2A measured at the tail. (Either that or maybe one or two of the 14 7135's aren't connected.)
I used kaptan tape to isolate the boards from each other in case things shifted during installation.
Hi is really high, with a steady climb to 4.2A. Low is really low, starting off at 50mA and settling in at 40mA. Strobe is hi fast strobe ~1.4A average RMS draw.
And finally, the beam shots. Same camera settings for each. ISO 400, 0.4sec, F3.5 IIRC. White balance set to Daylight 5200K. Between the de-doming of the cool white emitter and the aspheric lens, it has a very nice neutral tint now.
Flood Low:
Flood Hi:
Zoom low (notice you can see that the damaged phosphor areas projected in the image, but they still light up):
Zoom hi:
I'm looking forwatd to seeing this light get even more powerful at the same drive current with an XM-L emitter installed.
Oh, by the way, prior to installing the driver sandwich I had set up the SST-50 for direct drive and measured up to 6.0A at the tail through an in-line DMM as the emitter heated up. An AW IMR18650 only direct drove this same emitter to 3.5-4A in similar sized light (UltrFire C8-A1), but thermal management in that light was much more robust. The KD switch adds more resistance than the DMM does, but after a minute or two at whatever reduced current that provided, the battery didn't get warm, but the front of this light got quite hot. I'm hoping the XM-L and the 4.2A regulation will allow me to run it for 10-15 minutes at a time without overheating. I sure don't want to modify that driver sandwich again if I can avoid it.
I started the receipie looking for the most compact flood to throw light that I could fit an IMR 22650 in. (Not 26650, but 22650). The SacredFire NF-08 was perfect. Same size lens as almost all other flood to throw lights, but no wasted space in the bezel diameter. The whole light has the same diameter from head to tail which really appealed to me for keeping in the coat pocket. The tube, intended for 3AAA carrier is not much fatter than 18650 flood to throw lights, which despite having narrower tubes, for some reason mostly have larger heads when the same lens is used.
The second ingrediant obviously is the LiMn 22650 battery, which was the inspiration for the project. I wanted to be able to run an XM-L to the edge and stay in regulation for as long as possible. The extra capacity gives the light the power headroom I wanted without dramatically increasing the size like a 26650 or 26500 cell would.
Here's a pic of the light next to this oddball battery on the charger:
From the front, you can see the de-domed SST-50 LED with phosphor damage in two of the corners:
You might notice the tail boot is kind of pointy. To handle the current and provide forward action, I replaced the stock switch with a KD fwd click switch. There wasn't much boot stub to cut out to make room for the taller plunger, so the boot now protrudes a bit more than before. No biggie.
The final and most complicated ingredient was a driver sandwich. For the base, I'm using a 17mm multimode 8*7135 board that lets you select the modes available by soldering stars on the ground ring. (I got this one from KD, but I think ShiningBeam has the same or similar item.) For the available modes, I chose Hi-lo-strobe. In EDC lights, I like to have the strobe handy to point at the ground to get drivers attention if necessary while crossing an unlit street at night.
Two 15mm 3*7135 boards are slaved from it for a total of 4.8A regulated output in hi mode. It was a real challenge getting everything to fit in the pill, and I used the wires supplied with the 2.8A board instead of my usual 20 awg copper. I think they might account for additional resistance causing hi mode to top out at 4.2A measured at the tail. (Either that or maybe one or two of the 14 7135's aren't connected.)
I used kaptan tape to isolate the boards from each other in case things shifted during installation.
Hi is really high, with a steady climb to 4.2A. Low is really low, starting off at 50mA and settling in at 40mA. Strobe is hi fast strobe ~1.4A average RMS draw.
And finally, the beam shots. Same camera settings for each. ISO 400, 0.4sec, F3.5 IIRC. White balance set to Daylight 5200K. Between the de-doming of the cool white emitter and the aspheric lens, it has a very nice neutral tint now.
Flood Low:
Flood Hi:
Zoom low (notice you can see that the damaged phosphor areas projected in the image, but they still light up):
Zoom hi:
I'm looking forwatd to seeing this light get even more powerful at the same drive current with an XM-L emitter installed.
Oh, by the way, prior to installing the driver sandwich I had set up the SST-50 for direct drive and measured up to 6.0A at the tail through an in-line DMM as the emitter heated up. An AW IMR18650 only direct drove this same emitter to 3.5-4A in similar sized light (UltrFire C8-A1), but thermal management in that light was much more robust. The KD switch adds more resistance than the DMM does, but after a minute or two at whatever reduced current that provided, the battery didn't get warm, but the front of this light got quite hot. I'm hoping the XM-L and the 4.2A regulation will allow me to run it for 10-15 minutes at a time without overheating. I sure don't want to modify that driver sandwich again if I can avoid it.
