Techjunkie
Enlightened
(White-wall beamshot comparisons in post #8)
A while back, I experimented a bit with different direct drive solutions for an SST-90 emitter. In the process, I had created a Mag 2D with a very low resistance, high current capable 4s2p AA configuration. Eight AA Duraloops providing 4.8V in that torch proved to be too much power to direct drive the SST-90 with, driving it to more than 14 Amps.
Since then, I've been collecting the pieces to build something new from that host. First, I needed an inexpensive regulator that could fully drive an SST-90 from 4.8v input and fit in a small space. Enter three single-mode 2.8A 8xAMC7135 regulators (cheap ones from KD).
I also wanted to use the 40mm deep SMO Mag Rebel reflector, which is just awesome. It wont focus anything north of the top of the Mag tube, so recessing the SST-90 into the neck was necessary. I asked another, VERY KIND CPF'er if he'd turn a bit of Aluminum stock into a plain flat heatsink for me, and several days later, one arrived in the mail! :twothumbslovecpf What a good fit too! I really had to apply force to fit it in the neck after greasing it with Arctic Silver. He even cut a relief into the bottom for me to fit a driver, and it was a good thing too, 'cause I ended up needing that space.
Here's a pic of the heasink after I drilled and tapped six holes by hand, and the three regulators after I prepped them with 20awg stranded copper:
I used thicker 18awg stranded copper to connect the combined regulator leads to the switch and to the emitter's star.
I mounted the bare emitter onto a standard 20mm CREE XR-E star using solder paste and a frying pan. (Delicate work that I'm not too fond of.)
In the end, I had not recessed the heatsink enough to entirely fit the whole depth of the Mag Rebel reflector and still screw the bezel/head passed their gaskets. I solved that problem by cutting off the top lip of the reflector and then slid the reflector through that ring-shaped piece to give it something to hang from. In effect, I moved the lip 1-2mm down the reflector. (I also trimmed 1.5mm more than necessary from the bottom, but that doesn't appear to have affected focus.) You might see a very slim black ring around the reflector in the pics. That's the exposed edge of the cut reflector. I used a black sharpie to hide the raw blue plastic.
(Current draw shown in pic above is just the sudden in-rush at first touch of the DMM leads. It instantly settles down to ~8.4A. I just couldn't juggle the leads and the camera to snap off another in-focus shot.)
I might redo the reflector and cut 1.5mm less of the cam off, although the fact that it doesn't directly contact the brass screws that hold down the star might be the only thing keeping its bottom from melting.
I might also do some green glow around the emitter, although the screws and wires would still be visible 'cause they're taller than the emitter base.
I might just not mess with it again and call it done...yeah, right, like I have that will power.
A while back, I experimented a bit with different direct drive solutions for an SST-90 emitter. In the process, I had created a Mag 2D with a very low resistance, high current capable 4s2p AA configuration. Eight AA Duraloops providing 4.8V in that torch proved to be too much power to direct drive the SST-90 with, driving it to more than 14 Amps.
Since then, I've been collecting the pieces to build something new from that host. First, I needed an inexpensive regulator that could fully drive an SST-90 from 4.8v input and fit in a small space. Enter three single-mode 2.8A 8xAMC7135 regulators (cheap ones from KD).
I also wanted to use the 40mm deep SMO Mag Rebel reflector, which is just awesome. It wont focus anything north of the top of the Mag tube, so recessing the SST-90 into the neck was necessary. I asked another, VERY KIND CPF'er if he'd turn a bit of Aluminum stock into a plain flat heatsink for me, and several days later, one arrived in the mail! :twothumbslovecpf What a good fit too! I really had to apply force to fit it in the neck after greasing it with Arctic Silver. He even cut a relief into the bottom for me to fit a driver, and it was a good thing too, 'cause I ended up needing that space.
Here's a pic of the heasink after I drilled and tapped six holes by hand, and the three regulators after I prepped them with 20awg stranded copper:
I used thicker 18awg stranded copper to connect the combined regulator leads to the switch and to the emitter's star.
I mounted the bare emitter onto a standard 20mm CREE XR-E star using solder paste and a frying pan. (Delicate work that I'm not too fond of.)
In the end, I had not recessed the heatsink enough to entirely fit the whole depth of the Mag Rebel reflector and still screw the bezel/head passed their gaskets. I solved that problem by cutting off the top lip of the reflector and then slid the reflector through that ring-shaped piece to give it something to hang from. In effect, I moved the lip 1-2mm down the reflector. (I also trimmed 1.5mm more than necessary from the bottom, but that doesn't appear to have affected focus.) You might see a very slim black ring around the reflector in the pics. That's the exposed edge of the cut reflector. I used a black sharpie to hide the raw blue plastic.
(Current draw shown in pic above is just the sudden in-rush at first touch of the DMM leads. It instantly settles down to ~8.4A. I just couldn't juggle the leads and the camera to snap off another in-focus shot.)
I might redo the reflector and cut 1.5mm less of the cam off, although the fact that it doesn't directly contact the brass screws that hold down the star might be the only thing keeping its bottom from melting.
I might also do some green glow around the emitter, although the screws and wires would still be visible 'cause they're taller than the emitter base.
I might just not mess with it again and call it done...yeah, right, like I have that will power.
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I saw your YouTube video of the aspheric SST-90 and the clamp meter. Have you been able to make any direct comparison between the Rebel reflector and the more common incandescent reflector? How long can you run it at full power before shutting down? Beamshots?
