integrated battery charger

[tnnelectro]

Hi,
I have to make a circuit that can load up to 8 mobile devices (apple, android ...)

I wanted to know if there is an integrated that simplifies my life, which indicates even when the device is in charge ....

thank you in advance.

 

[dave9]

The devices have their own charge circuit, only needing the same voltage and sufficient current supply as specified (or included with the product).

All such devices that use Li-Ion batteries must have this to protect themselves and the rest of the world from battery damage which can result in fire.

If you mean that you need a single power supply to charge all 8 simultaneously, if they happen to all be 5V there are ready made USB power banks for this. The device itself will show if it is charging.

Perhaps there is a language translation issue, if the above does not address what you meant then can you elaborate?

 

[tnnelectro]

thanks for your answer,
in fact I thought to use an LM7805 for each output ...
the only thing I do not know how to put a led that tells me when the device is charging ???

 

[dave9]

I don't understand a reason or purpose for what you're suggesting. You'd need a bulk power source anyway in order to have a higher DC voltage to drop voltage down to 5V with LM7805 but LM7805 is a lossy, low efficiency linear regulator so that makes your bulk power source need be all that much higher in voltage capacity which raises build cost in addition to the power bill and heat management and sheer size of the assembly to deal with heatsinking and/or a fan.

Plus some mobile devices charge faster with a little higher than 5.0V. USB chargers are a dime a dozen these days, I probably have a half dozen spares in my junk drawer and don't see any reason to build such a circuit and mostly negatives in doing so even if it were free from scavenged parts.

What is the specific need you have that is not met with existing, higher efficiency ready to use products?

If you were instead looking to charge Li-Ion batteries directly without them being in the portable devices, then there are existing charge controllers dirt cheap on eBay that will do this, but that seems like a big hassle because you still need to fabricate a charging bay for them which would take many hours to make to exacting size and with springed battery contacts in just the right place, and needing a different one for every different battery.

 

[tnnelectro]

Hi,

I wanted an opinion on the attached circuit to charge the battery of any mobile phone and tablet ...

thank you.

 

[dave9]

The question is why you need this, what you plan to put it in, why you can't just use a standard USB charger product?

It doesn't eliminate needing a power supply in front of it and that PSU could just be a regulated 5V. Remember the products themselves have charge controllers in them.

Also some ready built charger products might support Qualcomm quickcharge #(n) (or whatever other quick charging standards there might be now) which can speed up charging for devices that support it.

 

[tnnelectro]

Ok all the considerations ...

but an aid to make this circuit work just for the pleasure of making it happen?

and if I wanted to add a led that tells me that the device is connected and charging ???