Help with circuit to use either batteries OR a DC "wall wart" power pack. Answered
I would like help with the type of circuit used in devices that can use either batteries, or a "wall wart"(AC to DC), or possibly even an AC cord if I decide to go that route (like a battery/ AC powered radio). I have a basic knowledge of electronics, but need help with this one. Is it very complicated? I'm not sure of specifics at this point, such as how many and what types of batteries (AA, AAA, 9V) what voltage, etc., just need to know how to build a circuit for this purpose. My project will use a single bright L.E.D, or possibly more, (maybe 3 watts each) and I would like to have the ability to plug it up if someone either doesn't have the batteries, or would just prefer to plug it up at all times. How does the device switch between battery and plug in? Thanks for anyone's time and help! I really do appreciate it.