My name is Renato and this is my first post in this forum so I'd like to apologize in case it's the wrong place to add some doubt about the subject.
It's not strictly about Arduino but searching all around I didn't find better place...
I'd like to build a portable music player based in these chineses MP3, BT, FM and USB players for the signal and a PAM8403 amplifier.
Studying the player, despite of the manual information (this needs 7v to 12v) I've discovered that there is an regulator 7805 type before all the circuit, soldered in this board. So I've jumped the IN and the OUT pins and the player works fine with 5v. The same manual says it takes kind of 200mA.
The amplifier, based in PAM8403 chip, deliver 3w@4ohm x 2 (stereo) and uses 5v. It's eficiency, as the datasheet says, can be near 80%, what means that in low volume it can take, say, 1A. But what if somebody likes louder sound? This gadget probably will end in my grandaughter's hand, rs...
To feed both circuits I've build a real 5v/3w PSU. But it doesn't makes my gadget portable. So I thought I could use a 18650 Li-ion battery that promisses 8.800mAh. And now I have to recharge this battery. I've found a circuit based in TP4056 to manage the charging. And as this battery says it deliver 3.7v, I thought using a XL6009 stepup mini board between the battery and the sound set (player + PAM8403).
Finally (excuse if this posts became bigger), I thought I could double all the power source schema, as can be seen below, to prevent overloads. Every device, except the amplifier, works, as far I understood, near 1A.
1 - Can I, at the same time, charge the batteries and use the sound set? Won't that overload the charger manager (TP4056)? Or, at least, get the charging manager "a little confused"?
2 - Can I build an output after the batteries to charge a cell phone via USB? In another words, can this gadget works as a power bank and yet playing music?
3 - What if I put an capacitor, say 1000uF/16v, between the power and the sound sets. I ask this because this batteries, as long as I know, are made for continuos uses like lighters to hunt and the amp could ask the batteries for instantaneous current.
Any other comment or suggestion will be very appreciated, as I'm just starting electronic as a hobby.
P.S.: Excuse my not-too-good English.
P.S.2: As I've clicked "preview", I don't see the picture I'm uploading to show you what I say. But I'm sure it's attached. If you can't see the too, please ask and I'll try to show in another way. Tks.