On 30/11/2015 19:46, Danny D. wrote:
Bob F wrote, on Mon, 30 Nov 2015 11:43:06 -0800:

It looks to me like it says "maximum power" 40 w.
It doess not say that is output power.

This is true that the package says "maximum power 40W"
which "could" be input power (but nobody cares about
input power - so why would they list it)?
https://i.imgur.com/30qxupn.jpg

The unit says the input is 100-240V at 800mA maximum,
but that doesn't calculate anywhere near 40 Watts.
https://i.imgur.com/8bl7ypU.jpg

100 volts (RMS) times 800mA is about 80 VA (aka Watts).

So, if the 40 Watts is input power, it's under reported
by 50% at 80 Watts actual.

If the 40 Watts is output power, it's over reported
by 15% at 34 Watts actual.

I don't think it's input wattage though, because that
would be reported in volt-amperes anyway (VA).


They could give specify VA, watts or both. Whatever they felt like
putting in the spec. The VA figure can be higher than the wattage if the
current draw in from the mains supply isn't in phase with the voltage.

--

Brian Gregory (in the UK).
To email me please remove all the letter vee from my email address.