Senior project, from washington!

[Justyhamby]

Hello! i joined this forum for help on my senior project for high school. its a requirement for all seniors to design and build a project, my project is to build a solar panel usb charger. I already have a design, i just need a mentor to assist on the technicals and to use as a example on my paper.
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This is what i have for design.
I just need someone that has experience in wiring and solar energy and willing to give advice.

[Sunking]

What is the resistor for? Let me make it real easy for you. You need a 6 volt 20 watt solar panel an LM7805 integrated circuit, and a USB hub connector. Stick a fork in it, done.

[Justyhamby]

thx, ive been useing this to base my design off of http://www.instructables.com/id/Sola...s-USB-Charger/ . my teacher said i needed a resistor, im not lookin for tips. I need a Mentor! someone certified with a degree!

[Naptown]

thx, ive been useing this to base my design off of http://www.instructables.com/id/Sola...s-USB-Charger/ . my teacher said i needed a resistor, im not lookin for tips. I need a Mentor! someone certified with a degree!

The only person to respond other than me has a masters in Electrical engineering and is a licensed professional electrical engineer. I think he knows what he is talking about. It is probably safe to say he knows a bit more than your teacher.

[SunEagle]

thx, ive been useing this to base my design off of http://www.instructables.com/id/Sola...s-USB-Charger/ . my teacher said i needed a resistor, im not lookin for tips. I need a Mentor! someone certified with a degree!

I did not see a resistor in the list of materials needed shown in that link for the Altoids Charger.

Maybe you mean the diode.

[Sunking]

OK let's try again. Here is the issue with your design. USB is 5 volts. Now look at the part list it is telling you to use a 4 volt panel. Do you see any thing wrong with that?

Here is the deal you need a panel of 6 volts or higher to charge a 5 volt device. The only real part you need is a LM7805 voltage regulator. It is a 3 pin IC With IN > OUT, GROUND. No other parts are needed except a USB Hub connector, a Altoid box if you want for a case, Solar Panel and some wire.

The 7805 is a 1-amp device. So you want a solar panel that has a minimum of 6 volts Vmp and 1 Amp Imp. So look for a 6 to 15 watt solar panel. All you need to look for is a panel no less than 6 volts up to 20 volts, and a current output of 1 amp. The 7805 is dirt cheap for $1 or less.

[Justyhamby]

Ok, i was just using that link as a overall design idea, i havnt decided how much power i want to make. I done only a little research, but 6v seems to be best to use. And yeah its diode, i think haha

[Sunking]

If you find a 6 volt panel and want to go cheap all you need is a single diode to charge 4 AA or AAA batteries.

[albert436]

I'll give young Hamby credit for sticking with this so far.

OK keep up the good work ! ! !

Keep us posted ! ! !