DIY Driver East-092 style (AMC7135 and DMG6968U)

Hi Scotty,

Option B. It’s a DIY project and would like to share this to whoever are interested. Like an open source software. :slight_smile:
:beer:

Hi Werner,

1. I think he’s using Allegro but I’ll double check when I get back to work.
2. I used Zilog MCU as I’m familiar with it and like to do it myself(DIY). I was reading the forum when Ohaya ask me if can take a look at the East-092 problem they were seeing and did some experiments as posted in the OP. I’ll post here a video of the actual testing.
3. D2 was in the original East-092 and carried it over in the circuit. Discussion about this diode here.
4. Good one on the gate pulldown. I’ll add that to the circuit and re-layout the PCB.
5. Not sure what you meant by testing the MCU output direct to the LED.
6. Yes it works in moonlight mode. See original post.

:beer:

Here’s a video of the testing I did for the OP. I’m just showing here the changing modes from 3% > 35% > 100%.

The idea of building a driver like this has been a fantasy of mine for quite a while. I say fantasy because I have no idea how to start. Please, keep up the good work and post an instructional for how to do it when you have it dialed in.

not to go off topic but when finished as a open source software would anyone no where to send to get made ? id like to get some made and for u guys as well ?

Awesome stuff. Sadly, if this is DIY I’ll never get one. I just don’t have those skills.

if i find time to do some research and with the creator permeation ill try to find a company to make the board and just sell to who ever ?

My skills are fledgling but I figure that as long as I can get parts and a diagram or set of instructions usefull to a non-electrical engineer- then I will get better with each build. After a few burns and some less than ideal builds I’ll get it. I think it would be really something to assemble all on my own.

dct33, I’ll bet you have more skills than you let on.

I thought a direct connection from another mcu leg to the led, so that the mcu can drive the led by itself with some mA. That’s because the LEDs will see very short spikes of full current maybe 6A or so in moonlight. Which is not optimal and often these tiny controllers have more legs than we need so it came to my mind.

Thanks for the link with explanation of the anti parallel diode, I doubt it is necessary but as it is an additional protection it is quite nice.

What is with a battery protection?
Just a voltage divider, read out by the mcus adc like on the nanjg boards?

The FET with the smallest Ron I could find was the irl3803.

I talked with pilot last week and he too uses allegro, I have also the plan/wish to learn how to use this’s one day.

Nitro,

That would be great. Yes I can provide the bill of materials and procedure on how to program.

:beer:

tivo i sent u a pm about your driver

Any chance of somebody collecting all the assorted parts and selling them in kit form? Assembly is easy - smear some paste around, drop parts into place, hit it with some hot air - ordering small quantities of the parts that only cost so little from all over, seems like one person doing the ordering then reselling everything together would be much more efficient. ;)

once i hear back from tivo i might hear back on a quote on some boards :slight_smile:

If you’re just using paste and hot air then shoot, I’d be in for a couple kits if available. But I’m looking for 2x18650 drivers mostly.

Yes, really easy. I use a butane soldering iron with no tip installed, it has a catalyst honeycomb thing inside that burns the butane so no flame comes out the end. Apply paste to all the pads with a toothpick (and in most cases it doesn't have to be precise, surface tension when it melts will pull the solder onto the pads and off anything on the board that isn't a pad), plop the components in place, then move the hot air around evenly over the board, components and everything, and when it gets hot enough the solder melts. Surface tension will snap the components into place on the pads, so alignment there doesn't have to be perfect either. Really neat to watch, the melting flashes across the board like a shockwave when it goes.

Shockwave? Sounds pretty cool! I’ve used hot air to clear boards before, but this sounds even better. Now that I think of it, I could re-flow emitters with the heat gun too. Probably run the heat from the bottom though. Then again, I might miss sharing the flashlight experience with my wife and her frying pan. :smiley:

It's actually easier to put stuff together with hot air than it is to salvage stuff off a used PCB with hot air. Much easier. I think mostly because factory-made stuff uses lead free solder that needs way more heat, scorching can be an issue. Even flooding with flux and melting in some leaded solder before starting with the hot air doesn't always make it go smoothly.

The gate doesn’t need a pull-down if the processor output pin is driving he gate low (i.e. not an open-drain output).

In Eagle, you draw the board outline on the DIMENSION layer. You can make it any shape you want. Draw it with a .001” wide line so any confusion about routing the board to the inside/enter/outside of the line is of no consequence.

ThanksTexaspyro. Yes it’s not an open drain output. I think the purpose of the pull down is to quickly turn off the FET. But since I don’t see any problem including the moonlight mode we may not need the pull down resistor. :beer:

The chip should be able to drive the gate off faster than any reasonable sized pull-down… also a heavy pulldown resistor would limit the turn-on of the FET.