On Mon, 14 Sep 2009, Andrew Errington wrote:
On Mon, September 14, 2009 08:40, Nick Rout wrote:
<snip>
Good point which I suppose explains why the supplied one is rated
double the minimum...
Yes, but you don't know if the manufacturer has added a safety margin too...
True. As they say, you get what you pay for... its just that you have
no idea exactly what you paid for! :-)
Some devices assume the power supply will be crap, hence they must
scrub it, or the output signal will be noisy.
Other devices are just charging a battery so don't give a
darn whether the input line is noisy... just so long as it doesn't
burst into flames!
And other devices place the bulk, weight and expense of scrubbing the
power supply on the power supply unit.
And then, as I'm certain is with most cases, nobody actually
expended two brain cycles of thought on the problem...and everyone
wonders why there is this humming noise....
John Carter Phone : (64)(3) 358 6639
Tait Electronics Fax : (64)(3) 359 4632
PO Box 1645 Christchurch Email : [email protected]
New Zealand
