Kinda new to the forums, and i just started school in dec for electrical engineering so im not to far into studies yet. So i got a basic understanding of the basic laws, i can read a plan sorta, do basic formulas, and learn quick. So anyways on to what i need some help with. I am trying to build a portable sound system I have plans for a Digital volume control http://www.eleccircuit.com/digital-volume-control-by-ds1669/ a tone control http://www.zen22142.zen.co.uk/Circuits/Audio/t-ctrl.htm and the amp http://www.zen22142.zen.co.uk/Circuits/Audio/150wmp3.htm . I plan on powering it with a 12v rechargeable battery. What i want to do is add a usb power supply, solar recharge panels, and the option to run it off ac power while its charging the battery. So to clarify a bit on what i need help with is how to create a circuit that will take power from the battery to the main board, a 5v branch for the digital volume control and usb, and recharge the battery via a solar panel array and an ac source. I was planning on doing it on one or two of the large solder-able bread boards. I havent chosen a battery yet as i havent calculated my current needs yet. Any help is appreceatied if i missed anything let me know. Help, questions, comments, concerns, criticism all welcome. Thanks.