240W chargers were a thing even before that, for gaming laptops. The only difference here is that it goes through USB-C PD, instead of a large-ish barrel jack, right? 95% efficiency probably refers to the adapter itself, where it shouldn't matter that much. Additionally, GaN is now a thing, so efficiency should be better than what it was 10 years ago.
>> The company says it uses Weltrend WT6676F, ON Semi NCP1622, and JoulWatt JW1556 controllers, as well as GaN switching parts from both GaN Systems and Navitas “peaking at an amazing 93% efficiency” for this 180W adapter. Both those parts and Chicony’s assistance as a power supply manufacturer are obviously there for other companies to use as well.
So likely even less efficiency for the higher rating. I'm very interested to see how they're venting this heat passively.
The size of these kinds of high wattage passively cooled power adapters is dictated less by component density and more by what you can spread and dissipate through the enclosure with safe touch temperatures.
And with the new solid state cooling tech that is just now starting to be rolled out I imagine in a few years some power supplies will be actively cooled.
Apple's M1 in the MB Air is 10W TDP afaik. The PSU would be more constrained space-wise but it'd probably get somewhere about as hot as the passive cooled MBA at full load.
Is 12W meaningful heat? I mean, I have laptops that run 10-15W and it doesn't seem like much. I guess it feels hotter because it's a much smaller surface area, but not that much (laptop heat output is mostly over the CPU/mainboard anyways)
It doesn't get the chance to build up in a laptop because of the fan. A 20W phone fast charger gets much hotter than a laptop, even though they should only be wasting a couple of watts on heating, because they have no active cooling (and pretty poor passive cooling).