Update Oct 3: PD68 TripleDown/TripleStack - Tri-Channel Driver

Well I build my first driver for good or for worst… Now I’m trying to sort through bistro triple down so I can flash it to this driver. This is the version optimized for two less, but I’m going to use all three channels on one xpl hi.

I know it’s late but none of my driver boards should need the Zener for single-cell.

I hope it works out for you!

Pilotdog68, under the 7135 on the top of the board is the trace that can be cut to separate the 7135s on the back from the fet on the front. The trace is small, would that small trace carry the current ok? It’s probably common, but I never thought about how much current goes through these traces til now.

Ahh man… This is hard! I have so many questions :confounded:
I just realized I need to change the pin layout in tks bistro tripledown firmware. The layouts between board versions are a bit different. Do I just start changing pin labels in the attiny.h file?

You would probably need to change a few lines in tk-attiny.h in the section about “TRIPLEDOWN_LAYOUT”.

It may help to have the attiny reference manual open, to see which pins have which internal names.

Also note that the PWM on pins 5/6 works a bit differently than on pins 2/3, so you may also need to edit the first page of main() if you move any parts from one of those groups to the other.

Ok. I wil give it a try. Thanks! :slight_smile:

So… In the attiny.h file do I need to mess with the output compare register if I change the pins? All three pins need changing. FET is on pin6, 8x7135s on pin5, and 1x7135 is on pin3.

And also, In the .c file, do I need to mess with the PWM counter in some way?

Let’s see… I think you can just rotate the assignment of names to values like this…

#define PWM_PIN     PB0     // pin 5, 6x7135 PWM
#define PWM_LVL     OCR0A   // OCR0B is the output compare register for PB0
#define ALT_PWM_PIN PB4     // pin 3, 1x7135 PWM
#define ALT_PWM_LVL OCR1B   // OCR0A is the output compare register for PB4
#define FET_PWM_PIN PB1     // pin 6
#define FET_PWM_LVL OCR0B   // output compare register for PB1

… and then I think it should work. But with 1x7135 on pin 3 (second PWM counter), your moon mode is probably going to suck. IIRC, that channel is locked at 31 kHz but moon usually needs to be significantly slower than that. If the lowest PWM level is too low, you’ll need to recalculate the ramps. And the lowest levels will probably still be more voltage-sensitive due to the short pulse time.

Thank you TK! I will give it a try.

Introducing the TripleStack.

I am getting tired of springs not fitting on the little pad in the middle of the 17mm drivers, so I’m going to give this a try.

It’s basically a TripleDown Rev1 with some of the parts/configuration added that DEL has found give greater stability. It’s also only 15.5mm wide, which should fit inside the pill of a light that takes a 17mm driver (as long as the pill is tall enough too). The idea is that you then use a 17mm contact board, which is also linked below, allowing a normal sized spring to be used. Building it will be tight, but I was able to keep the components as all 0805 size. You should order the driver board in the 2oz/0.8mm option.


I’m also copying the info for my X2R adaptation from the other thread:

Interesting idea. I have had some slave boards for awhile that I have considered using in place of the backside 7135’s but never actually tried it yet.

Nice PD68!! Soon to be ordered

I should add, there are non-ground pads very close to the edge, so before inserting in a pill you will probably want to wrap some kapton around the circumference

Wow, I’ve missed out on a great thread thread. Guess I’ve been avoiding drivers and FW for quite some time now.

EDIT: 7135’s like to be kept cool. Especially, on fresh cells. You may want to think about moving them to the top of the bottom board where they will have a better heat sink path.

Good tip, but that would mean i addition to the two batt+ wires and grnd wire, I would have to run two pwm wires too….
I think I’ll try it like this for now and see what happens. What I really should do is source some of those square brass pins for a more stable stack.

How many solid header pins do you think it would take to carry the same current as 18awg stranded wire?

Edit: one standard 0.025”header pin is the equivalent of a 21awg. So for those of you that would actually use this, is it better to have a big hole to feed some silicone wire through, or 2-3 holes for these pins? This is for the ground connection between driver and contact board.

My thought is that the pins will give it better heat management. It would also provide a good structure for a potted driver.

I should have been more specific. Only the large set of 7135’s should be moved down to the bottom board. One or two on the top board should be able to dissipate their heat via the surface area of the upper driver and through the copper wires connecting to the bottom board. The bottom board doesn’t need a Batt. You can just run Batt straight from the spring to the top board/LED. Both the top and bottom board need Batt~~. So that wire would remain. All you need in addition to that is PWM feed and LED~~. So 3 wires total.

Oh.
Normally I try to make my drivers as useful as they can be for people other than myself, but I thought I would be the only one who liked the idea of the pins. So I did it “my way”. This involved reducing the driver size by 0.5mm (15mm now), removing 2 of the 7135’s (I usually only use 3 anyways), and removing the FET pulldown resistor (I’ve yet to need one, and they’re easy to stack on the FET pins themselves) . You can use just about any 0.025” header pins you want, but I ordered these just now.

Why did you have to remove the 7135s? You could split the placement of the three pins. 1 or2 where they are now. 1 at the via for r2. And one at the via for the bleeder resistor. You would need to move the bleeder via and the fet output just a bit to make that happen. The ground ring on the bottom of the driver board should be enough to carry the signal. What do you think?