BLF17DD Info Thread - Reference

I guess I should experiment with the different sized nozzles. I’ve only ever done one component at at time, and hold it in place with tweezers. With full air, it’s soldered down in seconds.

Turn the fan down and the heat up. I use the fan on around #4 and the temp at 310-330, I don't know what the actual temp is but nothing melts but the solder and nothing gets blown off.

Are you still using the YIHUA like mine?

Yes, 858D.

2008D

Ohh - I do all parts on a side at once. I use gentle circular patterns with the heat gun, until all solder contacts turn nice and shiny. This embossing heat gun is very simple - I've even used it for LED reflows. Think he bought it at Michaels, here: michaels.com/surebonder-proheater-tool, but it's labeled different now.

I have the 858D as well…I set mine at 300, lowest air setting, when I start I start farther back, let the heat soften the flux in the solder, it makes it tacky and the components don’t blow off the pads, once nice and warm close in to reflow the individual components

I like to make sure the FET is placed towards the center, trying to allow the positive lead some room to be away from the edge of the board. I know this can lead to issues with the FET being too close to the ATiny to allow a re-flash, but I’ve trimmed that side of my clip to make it skinny to facilitate this. I don’t usually flash on the board anyway, but like to allow the possibility to change firmware later

By keeping that positive LED pad clear it’s easier to keep it from grounding out on a pill. I also like to cut away the shelf in that area on the pill to make sure it doesn’t still contact the actual pad. I do NOT want a 30A capable cell shorting out in my light!

I’ve used about 25 of these FET drivers so far and am loving the power level they bring to the table. The hot cells like a 20R or C4 give full blown output, control can be found through use of PF’s or other less potent cell chemistry, enabling the user to limit a 6A+ light to 4A or so through proper cell selection. Simple as changing batteries. :wink:

One last thing I’ve started doing is to apply coverage of critical components with a coating of Arctic Alumina Thermal Adhesive. This is like extending the silicone sleeve to ensure contact cannot be made, thus further easing my mind on possible shorts and adding some support to the LED leads on the board. A very thin layer of AATA is easy insurance anywhere something might possibly touch.

All good points Dale! Yes - I tried to position the FET more to the left and up (in the pics), but it slid downward when the solder paste liquified - probably should hand solder the FET to better control it's final set position... I gotta incorporate all of these points in the OP somewhere... Thanx!

You may have done the most qty of these boards than anybody, including Richard.

You need to watch out for a short from LED+ to the pad under the FET, too. Not worth it to protect against a short in one spot if it causes one in another. I make sure the FET has the pad well covered and then solder the LED+ wire right up against the FET body, if the edge of the pad on the board and the edge of the pad on the FET line up that leaves plenty of clear space out to the + pad.

edit: and if the pill needs work for clearance to the + wire's solder pad, then the pill needs work. Lots of pills have a far wider step that is needed.

I mount my FET all the way to the right to allow room for the clip, I just finished up 10 of these and I think this method is about the best (the best I’ve found so far anyway), the 17dd is siliconed in place so theres no chance of a short to the host board from the components on the bottom, power and ground are pulled threw the connections on the top there.


Ignore the extra wire there, its for hooking up a power supply for testing and is removed before buttoning it up. I cant wait to run out of these old 17’s and order the new revision to make it easier to hook up the switch wire. Also note how I do the GND connection with a piece of braid directly to the FET source leg, I also scrape away the mask around the leg so its got more copper to solder to.

Richard has made far more than I have, FAR more!

Yeah Comfy, valid point there. By moving the FET away from the positive LED pad it also ensures the LED negative out that covers a large portion of the bottom of the FET cannot touch the positive pad. Lot of high amperage bits on this small board!

CK, all good points there as well for piggybacking. When I piggyback these I like to use Teflon coated wires for the power to the BLF board and double Teflon wires for ground. This gives me 3 very sturdy legs holding the BLF board away from contact, allowing it to float as it were. With the double wires attaching ground, it’s ground supply is ample. I’ll make note of using the ground leg of the FET though, good point that.

Edit: By the way Tom, in the pics above the FET needs to move to the Right and up, towards the MCU and away from the LED + pad. Sometimes I re-flow this side of the board using a solder paste mask from Texas Pyro. Then hand solder the other side. While I always use the mask for the FET side, sometimes I just use the soldering iron to make the contacts one at a time in order to not have to use the stove top in the kitchen for one driver. I have a 6” round 1/8” thick 304SS plate that I put on the glass induction element, re-flow on top of that at a 4 1/2 setting then remove to a 3” cube of 6061 for quick cooling. The tiny diode and the capacitor are the most tedious when soldering with an iron, but then I’m using the big round/oval bevel tip as well. lol And no magnification.

I've read and looked at the OP now a couple of times. The way you have laid out your pictures the content in them along with parts lists and a little description on whats being done has really given me the urge to give this a go. There are lots of other threads similar to this out there but this just seems right. Thanks Tom E.

Thanks for making the thread Tom E.

Have anyone found a way to get rid of the whine in the middle modes now? Ive just been using STAR firmware that you get from RMM. I thought comfychair had found a way to get rid of the whine on the SRK BLF DD driver, but there is a jungle of information out there about these drivers now.

If these could become 100% silent in all modes that would be great. Id even take low/slow PWM over whine.

Use fast-PWM. There's no reason to use phase correct anymore.

Thanks. Got the stuff to program, just have not tried it yet. Ill get to it since I now have a reason to do some tweaks.

What have changed since you now can use fast PWM? And why isn't Richard selling these with fast PWM?

Ohhh - I'm still using phase correct but these ol ears can't hear it.. Hhmm - gonna have to change. Forgot details how to convert and not sure of side effects - still can use low PWM value of 1?

Previously DrJones was the only one doing FW for momentary drivers, and the 'sleep' method he uses means the LEDs do not turn off completely in the 0% mode (that's the only way to turn off a momentary driver since the +/- remains connected at all times). Jonny does something different in his code (which of course I don't understand) that fully puts the MCU to sleep after the button is released. None of that matters or has ever affected the clicky drivers.

OP updated with latest BLF17DD board link and parts list. Added links and post #'s to get ref info from the gi-normous OSHPark thread.

Awesome info and tutorial. Thank you Tom E.