On Fri, Jul 03, 2026 at 05:49:51PM -0400, D. Hugh Redelmeier via Talk wrote:
(Confusingly, USB C is a connector, not a protocol or set of protocols. But the use of a USB C connector hints are supporting modern protocols.)
Yeah Thunderbolt is using the connector too and isn't USB. Some of the USB-C ports on my laptop have a lightning bolt next to them, so they are thunderbolt ports too. Some of them have a 5 as well which I think means thunderbolt 5 so up to 80Gbps. I wonder what devices can use that.
Not exactly. There are so many PD specs that you need to make sure that your power supply conforms to one that will feed your computer enough power. PD 3.2 is the latest in this article: <https://en.wikipedia.org/wiki/USB_hardware#USB_Power_Delivery>
Note: not all USB C cables support all PD modes.
Certainly true. The thinkpad one I got says it does 28 and 20V at 5A and 15, 9 and 5V at 3A. But it does mean if you do get one good PD supply it can cover everything. The little one I use for my phone says 5, 9, 15 and 20V, with up to 3A but max 30W (so 1.5A at 20V). I have one I use for my soldering iron which does up to 65W (20V 3.25A) as well as 5, 9, 12, 15 and 20V, both PD and QC 3.0. It apparently also has a 10W wireless charge pad on top. I never noticed that before.
And then there are proprietary extensions to PD -- Qualcomm QC, for example. <https://en.wikipedia.org/wiki/USB_hardware#Faster-charging_standards>
QC 4.0 (which is the USB-C version is a superset of PD and QC 4.0 power supplies are also PD compatible). QC 3.0 and older which were USB-A were definitely their own standard.
So: we went from a stupid diversity of connectors, easily visible, to an almost invisible set of compatibility requirements. I think that they are safe: mistakes won't catch fire.
-- Len Sorensen