Hello there,
What MisterT has posted in post #3 is what we here in America call an "RCA jack", but we do actually also call it a "Phono jack". We call it both here. So the thing that normally plugs into that we here can call either an "RCA plug" or a "Phono plug".
But what Eric posted in post #2 we call a "Phone jack". Note the 'e' at the end of 'Phone' not an 'o' as in 'Phono'. Of course the thing that normally plugs into that is called a "Phone plug".
So we have basically RCA=Phono here, and Phone is the different type.
But i agree a 'power connector' of some type is a better choice. The only problem we run into then is that there are so many different power connectors out there. First we have 5.5mm OD and 2.1mm ID, then we have 5.5mm OD and 2.3mm ID, then we have 5mm OD and 2.1mm ID, and the list goes on and on and on. I cant even remember all the different sizes.