Just a note before you post:
The primary intent of this thread is to assemble a focus group for hardware design and manufacturing and is specifically directed towards members interested in and capable of working together to solve this challenge. This is not meant to offer ideas of UI features, such as mode selections or voltage cut-off, etc. Please allow our pool of BLF extraordinary talent to colaberate. I ask that you withhold any unrelated comments to maintain focus… if that is even possible around here!
Designing a 17mm 3-6V +3A boost driver.
As most of us have been following along through several discussion threads during these past couple of years, the budget compact +3A 4.2V boost driver seems to have eluded us since the advent of XML. My thoughts are: that for such an affordable product to be successful and available to the masses, it must also be profitable for the vendor to produce in mass quantities. The idea of challenging a supplier to produce this specialty driver (with the promise of several more specialty drivers in the future) would guarantee their survival and provide us with a reliable vendor that is both capable and receptive in providing for our needs. Perhaps this is the wrong approach. It occurred to me that there might be several others that have tried but gave up with less than desirable results. Maybe they simply need a reminder and more encouragement to try again. The collaborative approach of open-source might be the added ingredient necessary to see this through. Or just perhaps the goal is unrealistic and impossible; given the budgetary and size constrains and other technical factors. Taking note of the larger driver sizes in most of todays name brand flashlights, perhaps the 17mm constraint needs to be re-examined. Does there even exist an off-the-shelf XML flashlight that boosts properly and efficiently @3A from a single 18650 cell? If so, maybe someone could examine that driver to provide the basis for a similar design.
Even if such a driver were to be produced (and given the capabilities of todays 18650-32650 cells) do you think there will be distinct advantages over the efficiency of 7135 based drivers or other similar offerings? -more specifically, towards the later half of cell depletion where boost will presumably become most effective. Of other concerns and considerations: efficiency and the amount of time while operated during the boost phase, as compared to the potentially higher efficiency of linear drivers before they drop below the curve. Its all speculative and maybe you can offer your expert opinions. In other words, what are the probable real benefits in run time with a noticeably brighter light via boost circuit throughout the discharge cycle, as opposed to the known high efficiencies of 7135 based drivers before the user (not the light meter) notices a significant drop-off? Im trying to explore the real world benefits through the eyes of the user to find if the boost driver justifies itself. Yeah… more speculation and maybe a waste of our time. Maybe this cant be answered until we have a driver to compare. Still, I had to ask…
I understand that no one wants to work for free and put forth a large effort, and then only to see someone else profit from their labors. But at the same time, I don’t think we will see any progress unless someone capable of prototyping such a design steps forward to donate their extraordinary talents… to later be copied and mass produced by our Chinese buddies across the pond. Is it even rational to think that such a device could be kept within the sub $7-10 realm if mass produced anywhere else? I doubt it. If anyone can design, manufacture and market this gadget on their own (below $10 delivered), more power to them! :bigsmile:
Basics or more?
Who doesnt want all the bells and whistles? I think everyone would love to see DrJones MCU of choice with his firmware flash, solderable stars to select output amperage and a user programmable UI. It comes as no surprise that we all have individual preferences and needs. If these can be added as part of the package, then more kudos goes to you! But at this phase, I think we will all be more than elated to simply have a working 3 or 4 mode boost driver.
Who will stand up?
Gentlemen, do we have any takers? Can a few of you collaborate and help support this design undertaking for the BLF group? Does the open-source approach sound feasible? At least then we/you would control the design, mcu, code and other variables. Other drivers could also be spawned if you are successful. Your help, opinions and collaboration are very much needed here.
If anything, perhaps we will all learn something through this exercise that might prove invaluable during a later phase. Im still not against contacting other vendors for the challenge, and everyone is free to do as they wish. But I think our internal opinion is more important at this time before choosing a direction to move forward. I feel that lessons have been learned from the other thread and a new approach is needed. Poor results most often occur where there is a lack of initiative, control, trust, communication and understanding.
Who? Not me!
Hey, if Im not the right guy as the proverbial “Project Manager” (now or later) I will gladly pass the torch along to someone else. I hold no title… Im just trying to help get this started and see it through. Like most of us, I simply want a good budget boost driver to become available to the masses. Speaking for the rest of us mortals, please help us make this become a reality. Its so far overdue!!
Thank you for reading and please post your ideas!