On 02/01/2020 08:56, polygonum_on_google wrote:
On Wednesday, 1 January 2020 22:36:07 UTC, wrote:
On Wednesday, 1 January 2020 12:01:19 UTC, polygonum_on_google wrote:

Just looking at monitors and keep seeing wattages that are questionable.

For example, a monitor rated at 30W. But which has a USB-C power delivery rated at 65W.

Simplistically, you'd add 30 + 65 and rate it at 95W. But that doesn't allow for inefficiencies. Also, if you were looking at the specs to decide whether it would run from your UPS or some other low-capacity source, you'd want to know the maximum load it could impose.

There are bound to be rules about such things. Anyone know what they are? I'd have hoped there might be a dual rating - first, with no power delivery and second, with maximum power delivery.

The nameplate power rating is the max power a device consumes. It must be ignoring any usb load, regarding that as some other appliance's consumption.


NT

Agreed - that does appear to be the case. But should it be allowed? It is like a power supply being rated at zero (or, maybe, an allowance for losses).


ITYWF there are rules - and different ones for different purposes. So it
might help if you were more precise about where this 30W figure appears.
Eg EU-mandated Energy Efficiency labels are meant to convey typical
consumption. So 30W on such a label would (as I understand it) ignore
the fact that a monitor might be charging a laptop or whatever - and IMO
quite rightly do so.

--
Robin
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