When a device was originally designed to take batterys and you want it to be wall powered I thought all you have to do was get a DC adapter with the correct voltage, (for example if it took 2 AA you would get a 3v adapter or if it took 8 AA you would get a 12v adapter) and make sure the adapter had enough amperage and it would be fine.
It turns out I don't know very much about electricity considering I have damaged 2 different devices attempting this. So what additional information do I need to account for in order to actually accomplish this task?
Yes, in theory, you get an adapter with the same voltage, *but*, many adaptors that claim X volts actually put out many volts higher, especially if not under full load. Always measure the voltage of the adaptor with it connected to nothing. The newer lightweight small adaptors are more likely to output the claimed voltage, since they use switching power supplies which are inherently regulated.
Current-wise, a 500 mA should be sufficient. It's OK if it has a higher rating. If the rating is too low for the device, the voltage will drop below the rated output, or the transformer will get hot.
And some devices might have multiple taps to the batteries, not just at the far ends of the series connection. That's usually fairly easy to tell by looking at the contacts.
I once powered a portable CD player like this, using a slick little adapting device made of tape and aluminum foil. I took a piece of clear tape, put a foil strip down the center, then put more tape on the other side, except the end where some of the foil was exposed on the battery contact side. I did the same for the two battery contacts, then ran that super-thin conductor out and connected power, with batteries in the compartment to press the foil ends to the contacts (but with no contact with the batteries). Just an idea if it's hard to fit wires, as it was in this case.
OK, that makes sense. I will check the voltage myself next time to avoid more cooked circuits. thanks