Apologies for the vague-ery, and basic Q's below. I will do my best to clarify and research further where necessary.
tldr; can I "safely" replace a 6v pack (4 AAs) with a 8.4v pack (2s lipo) in my toy? If I let the smoke out of something, will it be a cheap something I can replace myself.
[Solved]: yes I can. 2s is fine for these toys.
Brief background
I'm using arduino nanos as general helpers in a few Nerf projects. Things like controlling motors, adding displays, adding addressable lighting etc.
I've now got my grubby paws on some Nerf laser ops blasters.
The toys
The laser ops blasters work like most other laser tag toys, emitting / collecting IR (they have already been decoded on this very forum). They also have BT functionality to connect to an app.
There is very little to the electronics save for the collecter, emitter, a BT module and some kind of uC. That said the bigger, higher voltage, toy has two 130 motors to power some gimmicks.
What I want to do
The bigger blaster, called a DeltaPoint, is powered by 6AAs (9v). I intend to run it off an RC car 2s lipo pack (8.4v) because all my AAs seem to be in my daughter's four furbies. I'm sure it'll do just fine.
The smaller one, called a AlphaPoint, is powered by 4 AAs (6v). Although I see 4 AAs replaced with 2s packs in other hobbies (in RC TXs) I am slightly nervous about the 2.4v increase.
Research so far
Internals pics show what seems to be a very similar, but not identical PCBs.
Questions
Is it safe to assume the visually "similar" design of the PCBs means they will run at similar (max) voltages?
Should I just stop wasting your time and mine, and stick a 2s pack in there to test? - These toys are under £5 each?
If I blow something up, will it be a cap, or resistor or something that I could replace?
Where I work we have boards (not Arduino) that run from 5V. They have an on-board voltage regulator so the customer can use a higher voltage, or there is a jumper plug (AKA "shunt") to bypass the regulator to run from a 5V supply.
During our tests the regulator is not (supposed to be) bypassed and I run them at about 7V. But, sometimes the jumper is accidentally in the wrong place so the components are "over-voltaged". I've NEVER seen damage from ~2V extra.
However, 12V will ALWAYS kill the RAM, and sometimes one or two other chips.
I'm not surprised. RAM has the highest percentage of the smallest critical dimension on the die. In other words: it's finicky, thin, sensitive stuff if you'd study it under the microscope. No wonder it's the first to go.
It's a lot better, but still not good enough;)
The main thing I'd be looking for is the power input part of the circuit. It's likely this consists of essentially a linear regulator and some filter caps, and not much more. At least that's what the photos you posted suggest; I see something that might very well be an LT1117 regulator. In this case, it's a matter of determining if the same regulator is present on both types of PCB's and what its maximum ratings and output voltage are. There's a good chance that in the fancy product the motors etc run directly from battery power and the rest of the electronics run at 5V or 3.3V supplies through the regulator, and that this part of the system is more or less the same in both types of product. But again, good photos of the internals of both products would be required.
Frankly, in your place I'd just drop the 5 quid a piece and start hacking
Have fun!
So I opened one of these up today to install a 3d printed part (that didn't go well, see below).
I've taken some better pics of one board (I don't have the other yet) because I'll no doubt need them anyway. Apologies for the rotation etc. Couldn't work that out in Imgur.
As for the printed part. This evidences how much of a dufus I am: I printed a tacti-cool rail attachment from thingiverse. Only to find it replaces the translucent light cover for the team/hit etc LEDs. What colour did I print it in? Black, of course!
Lesson learned: don't mess with toys you haven't seen in the flesh yet!
(1) I can put out a PSA to the nerf community, as many nerfers who may be interested in the Laser Ops series will have lots of lipos lying about for their dart-shooting guns;
(2) I can get on with:
(2a) my arduino projects I had planned for these; and
(2b) designing an appropriate replacement battery tray to 3d print.
