[WIP] 17mm DD+single-7135 driver / single sided / Dual-PWM

Hmm I don’t suppose you have a parts list/shopping cart for it?
.
I might just wait till someone smarter than me tests it

Exactly the same cart as the A17DD-SO8, plus a single 7135. :slight_smile: Refer to page 2 of the AxxDD-SO8 thread for the cart links.

Nice. All of the different FET types flying around has got my brain in knots.
Sharing = Simplicty

I forgot to mention that those vias are extremely close the the edge of the board. If there was a problem, that’s where I’d expect it to be. That’s something I expect to tweak. I don’t think that OSH Park will fail to plate the vias, but the GND vias do not meet OSH Park’s design rules. Assuming that the vias are drilled and plated this could result in only partial plating of the through-hole itself. It will certainly result in the vias not being entirely surrounded by copper on at least one side of the PCB (the bottom side). I expect the line to cut directly through the middle of the vias. What I expect is to see something like what led4power gets over here (but slightly worse): FS: LD-1 driver (5Amp pwm-less linear)-SOLD

Nice…single 7135 for low modes and a FET for DA POWAH!

Awesome build wight…good job!

12 Ordered, oh boy, maybe I get to do a batch at one time again!

Which reminds me, stencil….

Wight, for whatever reason the board outline doesn’t line up with the components when uploaded to OSHStencils.com. Really doesn’t matter as the actual cut out’s will be aligned with the pads to use it, just thought you’d like to know something is off somewhere.

I don’t understand it, just use it and report it. :wink:

Very nice wight, feels very balanced with the max POWAH and battery saving lows, i can’t wait to see someone build it,
Would these work just like a A17DD-SO8 if the 7135 pad is not populated?

It would be very interesting to see a comparison on run times for the FET on low from a A17DD-SO8 and this one.

EDIT
And Happy New Year :party: guys

I got 5 of those fancy mosfets, I think I’ll try em on these drivers and see how they work out.

(That would be the SIR800DP)

Are the moon/low modes on the usual FET drivers really that bad?

Around 4-5 lumens. A lot of folks don’t consider that to be a moon…it needs to be sub lumen for that.

If you’re going for truly low then the range of battery voltage from fresh to empty is an issue. PWM levels which barely light an LED on a full cell (~4v) will not light an LED with an empty cell (3.0v to 3.5v). The 7135 should help with that.

Thanks WarHawk-AVG! I’m not sure that we can’t do better. I’d love to see it get a little more symetrical if possible and shrink a little tiny bit so that the GND ring vias can move inward.

Thanks cajampa! Again, the actually cramming all of this onto one PCB wasn’t something that I thought could be done before I watched RMM do it.

Yes, these will function like an A17DD-SO8 unless you do something to make use of the extra hardware.

We’ve seen this before, it’s not really clear to me why it happens. I did change CAM jobs, but I don’t know whether that is related. If I remember maybe we’ll try a different CAM and see if it does the same thing.

I look forward to see the result of this, i know we can’t hope for much more, but for me who just got in to this game and still dream of more lumens :slight_smile: the possibility is exiting.
And now we suddenly have the possibility of more max and lower low with proper long runtime if i understand things right.
All in a single sided easier to make driver.

And i would think that if there is less resistance in the driver with this more expensive FET it should get less hot also.

wight
Yeah i saw RMM thread but i don’t know if he released any ospark project for it and he said it was untested, anyway that is what i so enjoy about this place, the unrestrained intuition that runs in and out in these threads, where so many ideas are an iteration of something before.

Does the FET get shut of when it is using the 7135 for lower modes?

So theres really no reason to buy both boards right (except for Zener option)? I can just buy multiples of this one and use it for either driver?

Less resistance in the driver just allows higher current when the cell is fresh. The heat comes from the led so more current would mean more heat not less.

Oh Boy! More heat! Bring it!

That’s what I’m always looking for, hotter, brighter, whiter… a dragon slaying cell munching annihilator of a light! :slight_smile:

My son want’s to know the difference between disintegrate and vaporize. :bigsmile:

I meant that the driver should get less hot or is that never an issue on the FET drivers? i thought it was recommended to at least use a silicon cube on them.
I know the led would get more current thats what i am hoping will happen.

Pretty much.

  • The A17DD-SO8 is easier overall to hand-build than this driver.
  • One difference that stands out to me is the way LED+ bypasses are done on both boards. This PCB should be reasonably friendly to drilling a hole between C1 and the MCU without interfering with an SOIC clip much. The A17DD-SO8 can be drilled in the center of the PCB and hopefully not interfere with an SOIC clip.
  • I don’t think that there is space for an LDO on this design, so I do not expect to produce a 17mm LDO version for momentary usage like I did for the A17DD-SO8.

I give all of that a big meh. I’ve already made it clear in the AxxDD-SO8 thread that I don’t think lowering MOSFET resistance further will result in much/any more current. I’ll be happy to eat my words, but I would recommend against getting excited. I also agree with RBD: AFAIK the MOSFET isn’t producing a significant amount of heat. It should be stone cold.

EDIT:

The silicone cube is for a linear driver’s FET, not a DD driver’s FET. FETs don’t really produce heat when they are on or off, only when they are in between on and off. The linear driver purposefully keeps the FET in this “between on and off” region in order to regulate current. Doing so produces a lot of heat, but that only applies to linear drivers.

Thanks wight for clearing up my confusion, you are correct i had confused the two.
And now i know that a DD’s FET driver is stone cold, i had thought heat could be a problem nice that it is not.

Is it possible to make a linear driver with this kind of FET and the attiny? or is that another animal altogether :slight_smile: