Ok so it seems that there’s several different drivers you can buy for the SRK now, along with the tons of crappy ones that come stock in the lights. Someone suggested earlier today that each driver get it’s own thread for discussion. So if you need advice, have tips, have questions, want to post performance specs, or just want to say you did it right the first time, post here. I purchased one and have been unsuccessful in getting it working so far. It was suggested there was a short or that I need to now upgrade the LEDs that were working fine before I did the mod. Although I don’t have the time to discuss all the specifics with it right now, I’ll definitely post my queries later.
Anyway feel free to post anything you’d like in this thread as long as it’s tangentially related to the specific BLF designed driver made for Sky Ray King flashlights. The FET driver now available probably needs a whole other thread.
the one ready and tested. I did not have a stock pile of 7135s or the other parts needed. I have theses parts on order for another build as now tested fine.
From MTN ET,
Required Parts:
•(32) AMC7135 chips (can use less if less peak current is wanted)
•D1: SOD-323 Schottky diode
•C1: 10 uF 0805 MLC capacitor
•R1: 19.1K, 1% 0805 resistor
•R2: 4.7K, 1% 0805 resistor
•UI: ATTINY13A MCU (SSH or SSU pinout) …this may not be flashed?
parts kit on the way for the lazy, unwashed, with limited time as myself and without a way to flash tiny 13 ATM.
The driver blows my stock 6 amp board away thanks to the work of the BLF! Measured 11.2 amps from PS direct to driver using heavy gauge cable.
All these Oshpark boards are thinner than the original SRK boards, so it's possible for the driver to end up sunk too far into the head for the ground ring on the driver to contact the front surface of the battery tube. I use an old SRK driver to set the limiter on the drill press, add some big solder blobs to the new board, and then mill them down to the same total thickness as the original drivers. You can do the same with a hand file, it just requires a little more fiddling & measuring as you go.
Add the solder blobs AFTER soldering all the other components, otherwise the heat from reflowing will mess up your carefully machined spacers.
If you have a light with spotty anodizing on the threads in the head/battery tube, and the new driver is grounded to the head, you'll no longer be able to lock out the light by loosening the head. The driver ONLY needs to make an electrical connection with the front of the battery tube, there's no need for the head to be grounded, the driver handles all that. So, if you can prevent the driver from grounding inside the head, using a thin ring of plastic, or by filing down the upper ground ring surface on the driver so that it clears the step in the head, it won't matter if you lose some anodizing in the threads. Any time the head is unscrewed far enough to break contact between the battery tube & driver, the light will be fully locked out.
I also use a round file to make a notch, for easy removal later with a 90* scribe or other homemade tool.
I’ll try your idea with the solder blobs. I tried to flow a thick ring of solder around the entire driver, but it may have still not been making good contact. I went ahead and ordered some new noctigons and some wire… so when that comes in I’ll see what that gives me. Mine sure won’t be as pretty as your though. I might have just bought an M6 to begin with because now I’m nearly $60 into this Sky Ray king, and that does not include the original $45 I spent on it. Or the $25 for batteries. Jeeze.
Ok folks, so I finally got the Noctigons in. I added some solder blobs to the top battery ring to make the driver thicker, but that still didn’t do the trick. Looking closer at my SRK, the interior of the head where the top of the driver would make contact was anodized… so I wondered if that was even my issue. I would occasionally get some flickering and once it lit up all the way. The only thing in this light that hadn’t been changed were the wires to the switch. I replaced those with much thicker wires, and bingo. That was it. It was the switch wires. I don’t know if there was a break in the middle of them somewhere, but sometimes it would work.
The driver works great, as does the nice warm 7B tint. The light now screams. The UI was a little strange at first. No mode memory. It starts at low and goes through the modes, and turns off after high. It sounds kind of sucky… but you have the option to go forward or backwards in the UI. Short presses take you forward and long presses take you backward. Also from off low is a single press and high is a long press. I actually like this UI, after I figured it out.
Your electronic switch wires carry little current and can stay small AWG, but as you found, they need continuity and not shorted.
The (-) return path is thru the battery barrel, the bare end, direct to top of driver board on outer ring. Inner ring is (+). Driver thickness is the issue so check out comfy’s post. No need to scrape anything but assure when barrel tightened down, the end makes solid contact with driver board. I used four point soldered wire braid to lock board into place and return path contacts. I messed up and took a little too much off when sanding the edges down. If you have flicker when bumped, then current path is intermittent.
I use button top batteries, flat top (+) may have contact issues with driver board inner ring.
I like memory mode firmware but SRK Special still way nicer than the original 5 mode clone firmware/software.
