The lack of solder mask on the edges is for heat sinking. Particularly at 2s voltages the 7135’s need as good of a thermal path to the flashlight body as possible in order to work properly.
I do not like solder blobbing the driver as it will wear the battery wrapper over time and could cause a short. Blobbing the battery does not cause this issue.
You are talking about the silk screen or the actual pads? The silk screen is a mistake, I added the logo at the last minute and it covered up the silk screen.
Ok then soldermask only need to battery side. On that side the driver not contacted with body so no heatsinking problem there. Other things Ok. I mean the text next to battery pads which shows me which is the positive and negative.
TA-Zy-T08-multicell - This is a driver custom made for the Zy-T08
This driver was requested as an easy way to convert the ZY-T08 to 2S operation for conversion to an XHP or MT-G2 LED.
The driver must be aligned with the cells with the body fully screwed on. Button top cells are required, solder blobbing the driver is not recommended, blob the cells instead.
The tailcap PCB MUST be modified to remove all connection to the body of the flashlight by cutting the traces. A Dremel works great for this.
The zener must be installed or you will fry the driver.
The R1 resistor will also need to be changed out to a 2S setup, 36K is popular. You will most likely need to recalibrate low voltage protection.
All the other parts are the same as a normal Texas Avenger.
TA, I would like to ask you if the new revised bistro with ~30 modes is going to be disponible in the near future. My TA drivers are anxiously waiting this new firmware.
I am waiting for TK to get finished with the updates to compact the firmware to allow for said 30 modes. I am already well over the space allowed and can’t do anything more until I get the code back from her. She has been real busy with the Convoy firmware recently and I don’t want to bug her for this.
As soon as she finishes working her magic I should be able to knock out my changes to the modes ect in a few days.
The biggest thing I need is for people to let me know if there are any other special mode groups that they need/want before I fill up the rest with slight variations on the existing mode groups. Once I have the mode groups set I don’t plan to change them so that the manual for the firmware will remain valid for an extended period of time.
Although I might leave a few modes “blank” at the end for later updates.
I suppose we could move to tiny85’s but I prefer the 25 if it all fits on it, it is easier to fit on the boards and program on board.
The only other features I want to add before releasing a “final” version is get the internal voltage reference code implemented as a definable option for the 15mm boards and any thing that it might be needed later with.
Can’t wait for TK to finish this bistro revision.
Toykeeper and Tom E really brings a revolution in the firmware development. I really admire the work and dedication of then.
Got my first batch of the 15 mm triples in today . Wow, that was like 4 major designs back in this thread, here: Post #318 and here where ordered: Post #325.
Still wanna order those D01 boards too. Also by Friday, I should be receiving the Mouser order I placed for the full set of parts, including SIR400DP's and all the parts in 0603 size.
Yeah, I knocked out a few of the last things I wanted to do pretty quick. Now just waiting for TK to have time to finish up the bistro updates so I can release a final firmware version and I think I can wrap this project up till something new comes along.
The set of parts from Mauser elements includes LDO (MC78LC50NTRG) that does not have reverse polarity protection. MIC5235-5.0YM5 such protection is built-in.
Oh crap! Now I have to track back as to why I ordered those - thought there was a direct link/reference. Maybe I got the part# wrong. I really had no clue how to pick one...
Thanks for checking it out!
Edit: found one reference here: https://budgetlightforum.com/t/-/31955 by RMM in the OP. Thought these were the ones Richard uses in general, not just this buck driver... Hhmmm.
I have two LDO parts at home. One came directly from Richard, the other I think I ordered from Mouser earlier - that's probably why I ordered these, though I never tried either one as of yet.
Can I beg you guys to come visit a thread and explain how these LDO drivers work? I’m familiar with voltage regulators, but there may be a benefit to explaining those as well. Are different output levels achieved by PWM?
The reason I ask is: Would it be possible to replace the sense resistor in the regulator circuit with a digital potentiometer? Assuming that the LDO regulator is set up in constant current mode, sweeping the value of the sense resistor should sweep the current level accordingly, avoiding the need for PWM entirely. Add a FET for Turbo and it’s done.
BUT, I’m jaded enough to be pretty sure that if this was a good idea, someone else would have done it already, so I assume that I don’t understand how the circuit works well enough to know better.
Huh? Did you post this in the right thread? There is no sense resistor on triples. triples are single 7135, bank of 7135's, and a FET. The LDO replaces the functionality of a zener diode, to reduce the voltage of 2S or higher cells down to 5V or below to operate the MCU within spec.
Actually though, if 7135's were to get 8V or higher, don't think they will work well or last very long. So .... I'd probably not populate the 7135's - maybe the single - I think it survives for a low output - written somewhere on BLF, dunno...
Years back before FET drivers the only way to drive an MT-G2 was with a zener modded 105c. So I am going to say that the 7135’s handle 2s voltage, be it with more heat.
Now 4S voltage would only be for moon mode for sure.
True. Richard's zener mod kit was intended for the 105C driver, and that's what we were doing at the time. Don't think that lasted long before we started doing the comfy style FET mods to 105C's.
I really dunno - don't think there were any long term tests, either for longer run times or longevity of hours of use.
Yeah, the 7135’s seem to hold up fine for 2s voltage when I was researching them, even on those badly heat sinked 105c’s.
Now they might drop the current down when they get hot but they should still work. I figure there is room for them, so why not have them there. If they don’t work it is easy enough to simply not populate them.
. Wow, that was like 4 major designs back in this thread, here: