solar panel usb
Trying to drop across a solar panel on my math right?
Ok I have one of those cheap kind of load your car battery solar panels. I want to drop the voltage from 15V to 5V for charging USB devices. I have not tried it yet, but the package says 1.8W at 15V for 1.8W/15V = 0.12 Amps 5V/0.12Amps = 41.66 Ohms Therefore, a resistance of 42 Ohm should get me where I need to be? I figure if I break it I can only use a USB hub. I do plan to install a switch so you can switch between 15V to charge the batteries and the USB standard.
The easiest way to do this and still have all those that currently exist, would be to use a PIN of 7805 three regulators. It would circuitry and would not allow 15VDC available all the time to do the work of others. The connection is very easy and will be responsible for all streams you have available. Available output pins ar Radio Shack, as would be the regulator.
