Yet Another Solar Charger

Hi,

I've read some posts about charging batteries with a solar panel to be used with Arduino. But none of them (at least, none I've read) fits what I need. So I designed a simple circuit.

Before building it, I'd like to have some advice if it'll work properly. The schematics is attached. I will run a software on Arduino that reads A0 and when the voltage is 5v it sends a HIGH signal to 0. That is meant to stop the charging process of the 9v battery.

So what do you think of this design. Is it ok?

Thanks in advance,
Eduardo

Now it goes the schematics.

Eduardo

So what do you think of this design. Is it ok?

Powering a 5volt chip with a 9 volt battery will destroy the chip, no?

Lefty

Hi Lefty,

Actually, 9 volts is perfectly OK. The Arduino uses a voltage regulator. So, you can plug up to a 12v battery (see http://arduino.cc/en/Main/ArduinoBoardUno , for example).

Regards,
Eduardo

Actually, 9 volts is perfectly OK. The Arduino uses a voltage regulator.

I certainly know that (I am a God member, ;D).

However your drawing shows the 9vdc battery wired to the 5v pin, which would smoke the chip.

Lots of different ways to power an Arduino. Lots of people power their arduino boards directly via the 5vdc pin, using batteries or external regulated power supplies, however they must not exceed recommended 5.5vdc maximum voltage to this pin.

Lefty

Lefty,

I see. Sorry for the confusion. I should have put Arduino and not AVR on my schematics.

But, what do you think of the rest of my design?

Eduardo

But, what do you think of the rest of my design?

Looks practical and pretty simple. You would need to test it out and of course the software would have to be tested and voltage switching values worked out.

I should have put Arduino and not AVR on my schematics.

No, you should have the pin named Vin, not 5V.

Lefty