[LINK] Australian energy efficiency standards for personalcomputers and monitors

[jim birch]

> Also is the selection of a USB plug actually a good idea?   What if
> <insert clueless user> sticks one of these plugs into a USB port
> rather than a USB power port?

USB gender changers are not common so the plugs themselves provide an
implicit correct connection.  The plug itself comes in a few sizes so
can fit anything that requires a modest level of power.  As an added
bonus, it provides a standard communication mechanism.

I bet some Chinese engineer has figured the number of power stations
this initiative will save, not to mention the amount of manufacture of
different wallwarts avoided.  I'd expect some serious numbers.

from Wikipedia:

The USB specification provides a 5 V (volts) supply on a single wire
from which connected USB devices may draw power. The specification
provides for no more than 5.25 V and no less than 4.75 V (5 V±5%)
between the positive and negative bus power lines.[9] Initially, a
device is only allowed to draw 100 mA. It may request more current
from the upstream device in units of 100 mA up to a maximum of 500 mA.

If a bus-powered hub is used, the devices downstream may only use a
total of four units — 400 mA (i.e. 2 watts) — of current. This limits
compliant bus-powered hubs to 4 ports. The host operating system
typically keeps track of the power requirements of the USB network and
may warn the computer's operator when a given segment requires more
power than is available.

Some USB devices draw more power than is permitted by the
specification for a single port. This is a common requirement of
external hard and optical disc drives and other devices with motors or
lamps. Such devices can be used with an external power supply of
adequate rating; some external hubs may, in practice, supply
sufficient power. For portable devices where external power is not
available, but not more than 1 A is required at 5 V, devices may have
connectors to allow the use of two USB cables, doubling available
power but reducing the number of USB ports available to other devices.

A number of devices use the 5 V power supply without participating in
a proper USB network. These are usually referred to as USB
decorations. The typical example is a USB-powered reading light; fans,
mug heaters, battery chargers (particularly for mobile telephones) and
even miniature vacuum cleaners are available. In most cases, these
items contain no digitally based circuitry, and thus are not proper
USB devices at all.