On 29/01/2019 16:47, R D S wrote:
I'm looking for the wall wart for an exercise bike in my bin of such
things.
It needs 9v 0.5A and i've found one that's 9.6v 0.6A which (accepting
there's no danger of ever finding the original) is closer than I
expected to get.
But I have a 12v 1A with a longer cable, past experience tells me there
will be no bother using that but is it a problem? And if not when is it
likely to become one?

Depends on whether the bike has any regulation on its input. It probably
does (assuming this is just an electronic readout of speed / distance
etc). The 9.6V one would be the better bet.

And why do similar rated ones differ so much in bulk? Is this just a
build quality issue?

The main difference will usually be a light weight switch mode design vs
a older style linear supply. The older ones will have much heavier
transformers.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/