Faust - 12 hours ago »
grahamlthompson - 4 hours ago »
Faust - 53 minutes ago »
gomezz - 1 hour ago »
I think regulations only impose a limit for standby power usage on such devices but not restrictions for when in use.
It used to be the case that just about every electrical product would quote the power usage, many still do. Humax used to do until not that long ago.
Yet another example of treating the consumer as a mushroom.
You can only quote a maximum power which would indicate a max of 30W. We know the 4000/5000T powers down unused tuners to save power so it will depend on what the box is doing.
There's no point in stating the power requirement of a box with an external power supply as the max is obvious.
Well given your former career Graham I expect it is obvious to you.
However, I suspect if you took a click board round to your local shopping centre, stopped people and asked them what the power draw for said external power brick was you would get almost 100% blank stares.
Well most O level kids would know that power in a DC circuit is volts x amps. It gets more complicated with ac as phase angle between voltage and current affects the power (you have to add the Cosine of the angle to volts x amps)
A pure capacitance has a phase angle of 90 degrees (current leads voltage) and a pure inductance also has a phase angle of 90 degrees (voltage leads current). Cosine 90 is zero so in both cases power is zero regardless of voltage and current.
The power drawn from the mains will be a bit higher anyway as nothing is 100% efficient, transformers can be in the high 90% though.
| Tue 27 Mar 2018 9:48:54
#8 |
