How to build circuit that would offer power by way of either a "wall-wart", or through batteries. Answered
How is the circuit built that would allow a device to be operated by either a power pack ("wall wart") or through batteries. Like in so many toys it would be either/ or. It would automatically switch between one or the other, like, say you're out of batteries and still need this device to work, you can find either the power pack, or even direct ac. I have a radio for example, which I'm sure is like so many other devices of this nature, that can be plugged in (120 volt ac), or will work on the batteries. As soon as I unplug, it automatically switches to the batteries. Is there a circuit internally that changes the 120 volt ac to "wall wart" / dc voltage? Does anyone have a schematic for such a circuit. I don't have any specifics, other than the batteries being maybe 4 D cell batteries at 1.5 volts each (6 v). Thank you.