Hey djozz, check out the short inductor mod I did above to get the boost driver to fit. Maybe you can use those 12V LEDs afterall.
I missed your post somehow, so thanks! I will look into that and may try it. :+1:
I was going to take the lights on their first trail ride but the trails were unexpectedly closed. Instead I did a street ride to get an idea of the temperatures they’d get to. Ambient temperature was 80F. Had the lights on high for about 12 minutes, but the temperatures seemed to have equilibrated probably about 5 minutes in. SST40 light head temperature was between 120F and 125F, and the XHP70 light was between 110F and 115F depending on how fast I was riding and any breeze. Temperature was measured with a little IR thermometer.
80F is probably the hottest ambient temperature the lights would be used in, so they should be fine as long as I don’t stop for too long.
I swapped out the LED with SST-20 4000k FA3 bin from Intl-Outdoor. The reflector works great with this LED and makes a well defined spot and an even spill.
I agree with this. The reflector is a really good match for a domed SST20. Creates a broad (for this emitter/throw capability) and clean hotspot. I’ve swapped in a 5000K LH351D from MTN, and solder bridged the sense resistors. Running about 5.3A on a fully charged ‘Tesla’ Vapcell IIRC. I gotta say I just don’t like it as much with this emitter. Probably going to swap an SST20 back in it eventually. The girlfriend currently has this light hostage though…
Awesome host though! Well done and for the ~12 dollars that I paid for it, EASILY the best value I’ve ever gotten.
Thanks for that info. The modes still work the same?
It seems like there is some regulation going on. This comment is about the SD1 but I assume the drivers are similar. I’ve not seen any regulation/runtime graphs except for a short one in flashaholics review video that shows what looks like a timed turbo stepdown.
I have (had?) a video of the light connected to DC supply and sweeping through 2.8-4.2V or so. I don’t remember it being regulated. The driver sure is weird though. Mode spacing stayed reasonable, though did get a bit tighter visually. Meaning it’s now medium high turbo IMO. This really helped the tint of the sst20 though.
I’ll see if I can find the any notes I had from the modding.
My measurements for throw were something like 27kcd with the resistor modded sst20 and 16kcd with the lh351. I’m going to try slicing the 351 if I ever get it back lol
Edit: posted a first impressions/review a while back…
I see, thanks. So it looks like those are just current limiting resistors, as djozz suspected. Good to know you can just bridge them and at least get a decent FET driver.
Sd2 (stock) turbo voltage sweep Sd2 (stock) turbo voltage sweep - Album on Imgur
Here is that video…
very interesting light, build and use case. thanks for sharing it with us…
This light is currently on FLASHSale at BG… FYI
Could someone please point out the sense resistors to me?
They are the resistors marked R9 and R10 in the picture of the PCB shown in the OP.
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Is it better than Convoy’s buck 8A driver?
No. I didn’t know that when I ordered it but it’s ok. I think it’s a linear driver and Kaidomain said it has 4 groups but the explanation of how to switch between them doesn’t work …or I haven’t figured it out yet.
The driver isn’t on their site anymore but it’s still found on the AliExpress store.
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Tkank you. I’ve noticed this driver on KD but thought it would be far worse than Convoy’s. KD stuff also tends to exaggerate specs (even when tested with mains power supply) so I’m not sure if it can really reach 8A.
But thank you for the input. Maybe there are other advantages of this driver. Keep on testing 
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I swear I measured 7A+ last night but I can only see up to 6.6A with a fresh Molicel P42A, prime grade 50E or a Lii-40A and a clamp meter. I did reposition the press fit driver ring and that may have affected the ground connection.
Anyway, my goal was to avoid a fitting issue due to the shallow driver pocket but attain higher amperage than the stock driver. I have 2 so I’ll bridge the sense resistors on the other one.
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