PSU : prices and differences

[irving2008]

Fun fact #3: the actual voltage you get will depend on how far you are from the substation, further away will be lower, and will drop during ad breaks on tv :)

[njhussey]

I shall be watching this with interest as I'll be wanting to make a power supply for my router and am not very electrically minded.

All I know is you can't smell it (unless after and there's that burning smell...) you can't see it and that if (when you're small) your toy train set doesn't work don't go testing your shiny new mains transformer like you used to with your 9V battery controlled one (to see if the batteries were on their way out) and lick the wires........