"Dantanna" <(E-Mail Removed)> wrote in message news:...
> Lol - Thank you so much for that very detailed reply Fritz! This should
be
> a FAQ or added to the faq.
>
> Thanks again - .
>
>
> "Fritz Schlunder" <(E-Mail Removed)> wrote in message
> news:(E-Mail Removed)...
> >
> > "Dantanna" <(E-Mail Removed)> wrote in message
> > news:WE%1e.21637$(E-Mail Removed)...
> > > The main point of my question is to get a general idea on what kind of
> > power
> > > usage AC power adapters consume when plugged into a household outlet.
> > Why?
> > > Because even if you have nothing feeding off of the walwart it is
still
> > warm
> > > to the touch and that would indicate that it is wasting electricity
and
> > > costing money.
> >
> >
> > Indeed most wall cubes do waste a not totally negligible amount of
energy
> > when idleing. Exactly how much depends on the size and design of the
wall
> > cube, but an estimate of something around 2-4 watts while idleing isn't
> too
> > unreasonable for normally sized wall cubes. If in your house you have
30
> of
> > these cubes all plugged in 24/7 each taking say 3W, and you pay 10 cents
a
> > killowatt hour that amounts to around $6.50 a month down the trapper.
> Most
> > equipment you purchase will often specifically recommend you unplug the
> wall
> > cube when you are not using the product (somewhere in the manual, but
who
> > reads or follows those?).
> >
> >
> > > For example - I have a Sony Clie which is a rechargeable version of a
> Palm
> > > Pilot. I noticed that the adapter is rated to output 5.2V at 2000mA.
> My
> > > first thought was wow! What does a Palm Pilot need 2 Amps for??? So
> does
> > > the output rating with the Palm Pilot out of its cradle mean that the
> > > walwart is burning up my AC putting out a constant 5V/2000mA?
> >
> > Surely the Sony Clie doesn't need 10.4W during normal use, the high
> current
> > is surely needed for recharging the battery. If you want to charge the
> > battery in a reasonably short amout of time it takes a relatively high
> > current. I don't have a Sony Clie, but it probably uses a switching
power
> > supply type of wall cube instead of the standard transformer + rectifier
+
> > capacitor arrangement. Switching power supply wall cubes can (although
it
> > doesn't mean they have to be) be designed to use much less power while
> > sitting around at idle. These types of wall cubes usually do have
higher
> > efficiency while under load as well. Unfortunately they cost more, so
low
> > end cheap consumer products won't normally use them. Fortunately high
> tech
> > products like cell phones normally include them these days.
> >
> >
> > > Are they putting out a steady voltage and only providing current when
> > > current is called for? Or is the current also measurable even with
the
> > > device absent?
> >
> > Indeed a 5.2V 2000mA rated wall cube won't likely waste 10.4W when at
> idle.
> > They only supply 2000mA if the load wants that much. On the other hand
> most
> > wall cubes will waste something while idleing, and the current flow is
> > measureable. Although measureable, it isn't guaranteed that simple
> > power=current*voltage formula can be used to accuratly measure the
wasted
> > power. An idleing transformer is an inductive device and therefore will
> not
> > have unity power factor when at idle. Additionally capacitive loads fed
> > through a rectifier don't draw current in a nice sinusoidal pattern, and
> > they too lower the power factor (although this mainly only applies when
> the
> > wall cube is loaded).
> >
> >
> > > Bottom line is if these things are consuming power in idle mode - they
> > need
> > > to be updated to be intelligent enough to turn off when the downstream
> > > device is off or removed.
> >
> >
> > Well that would cost more and make things more complicated. If you like
> you
> > could go out and replace all of your standard mains frequency
transformer
> > based wall cubes with switching power supply ones, and assuming you get
> well
> > designed ones this may make the idle power consumption negligible as
well
> as
> > improve the efficiency while under load.
> >
> > But if you really are concerned about waste make sure not to buy fuel
> > wasting vehicles.
> >
> >
>
>
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