Added Charging Circuit(for modding lights with charging) OP Updated ME4057

Adafruit’s MCP73833 open source Eagle .brd and .sch files GitHub - adafruit/Adafruit_MCP73833_PCB: USB LiIon/LiPoly charger

Honestly it wouldn’t be hard to do, the hard part will be making a generic driver/charge combo board that will work in multiple hosts. The OP looks like a separate little charger board that you would stack on an existing driver, which might be the best route. (definitely the most versatile.)

Ok, I misunderstood. A combination driver/charger is what I thought the target was here. I thought the design in the OP was meant to just be a starting place for design.

I agree, that would be awesome, it’s just more specialized than generic. Using EagleEye as an example, If we made a board that fit the driver pocket and charger cutout/port in an X6R (which we sorta did), it wouldn’t work at all in an X5R, and vice versa.

Looking into the MCP73833

As a result of the feedback on the above circuit I redesigned a board using the ME4057 charger. This IC has solid specs and includes reverse polarity protection, recharge, and overtemp protection. The new design is below. Please give me your feedback!

I would like to bring a design to oshpark but i am unsure how to do so. In fact, what you see below is as far as I have learned of the design software DipTrace. I do not know how to prepare the design for printing. I don’t know what to do with the different layers such as silk mask or even how they are edited. So I’ll be studying up on that if anyone wants to give some pointers.

Anyway, here is the new design. It is on a 17mm board but could be sanded to 16mm without trouble to the circuit.





It looks good! (Says the guy who doesn’t know anything about what he’s looking at :person_facepalming: ) You should contact Texas_Ace about using Diptrace and uploading to OSH Park. He uses Diptrace for all of his designs.

Don’t worry. I pretty much feel the same way. I have to say I was a bit embarrassed/nervous to post this considering. :slight_smile:

I’m working on trying to edit the silk screen labels now

Anyone have a link to a good tutorial for uploading to oshpark?

Sorry, no Oshpark experience to help you out.

But a question: if I think about a light with build-in charging that I would like to upgrade, I think of the Supfire A2 (bad UI, low PWM). And in that light I would think of another approach: I would leave the stock board in, but cleared from components except for the micro-USB socket. That way the socket is fixed in its original correct position and I start with a big worry less. What I then need is an upgraded driver (a 17mm bistro driver would fit easily) and a minimised charging board that can be attached to the socket with wires, and looking at the number of components needed, that can easily be 10mm diameter (it does not even need to be round). Yet another approach could be starting from a one-sided driver (could be a bistro driver again, why not?) and add the charging components on the underside (it will be used floating so the battery side is not in use).

Just thinking out loud without the skills to contribute anything to an actual design :innocent:

Those are great observations! I have a couple a2s and feel the same way. I’ll look at it more and see if an fet +1 single sided version of TAs boards might hold this circuit. Also, certain lights that do not have charging, such as vg10, might be able to hold a board with a dremeled hole for the charge port. Lights without charging stock might be better candidates for the board as it is above. So I’ll also put together a board without the micro USB. This way it could be wired to any charging port desired.

I think I’ve found a way to use the stock charging circuit on the a2. It will add 16ua standby current in addition to the TA driver with Narsil. Not sure if that’s a big deal or not. I think I’m going to try it though.

Cool! Let us know!

I finished building the TA driver. I will flash it tonight and then hopefully tomorrow I can test it with the charging circuit from the a2. I’m not sure what implications it will have on the software. I’m not even sure if it will work at all but I’m going to find out:)

The driver is flashed with narsil triple. Narsil triple doesn’t have an indicator led support so it will only use the onboard leds when plugged in and charging. Tomorrow I need to remove the switch from the stock driver, isolate it from the contacts, and replace it with arctic silver or maybe epoxy. Idk? That way I can use the stock switch without turning the stock driver on when pressed. I am hoping that this will allow the stock driver to remain in standby mode only used for charging. All other functions will run from narsil.

All testing is a success aside from one issue.
You can see here they that the charging circuit works with the TA driver connected.

In fact the TA driver has full functionality while plugged into the charger. With it hooked up this way the MCU on the stock board never turns on. It runs in standby of only 16ua of battery drain. Now what I didn’t expect was the high standby current of the TA driver by its self, connected or on its own it draws 4.6mA of standby current. Now I did not expect this.

Is this normal for Narsil to draw this much power? Or did I compile/flash the firmware incorrectly? I’ll be looking into this now.

Well, I have found out that Narsil triple does indeed have a standby current of 5ma. This is quite dissapointing. I was excited about this build but now I’m unsure. Maybe I will try building another driver and use standard fet+1 Narsil. But all I have are triple channel boards and it would be a pain trying to rearrange the pin orders so I might put this one on hold for now. I know the pin arrangements can be altered in the firmware. In fact I’ve done it before but I forget quickly. It’s a pain having to constantly relearn things. I used to be quite sharp but I’ve lost my edge. Well even a dull bit can cut through wood if you push hard enough. Eh?

Edit: removed unnecessary personal issues.

I think I I have a way to easily convert the triple channel TA driver to use standard Narsil. I’ll give it a try

It looks like you’re a bit on your own in this thread, but I’m still listening :slight_smile: , it is crusades like yours, trying out stuff in a thought-over way, that brings modding inventions.

I’m still watching too. But, I can’t help either. Sorry! :blush: