On Wednesday, 1 January 2020 13:57:13 UTC, Dave Plowman (News) wrote:
Search DC power plug. Are you sure it is 6mm? Common is 5.5mm

Yes ... this page

https://myvolts.co.uk/product.php/10...r_power_supply

says that 5.5mm is OK for Type A.

Actually I've just compared the two. i can't tell the difference in the outer diameter between 4.4 and 6mm, but the inner hole is much thinner on the 5B supply and I think the pin is larger on the 5A. Hence (AFAICS) a 5A supply can be used on a 5B hub, but not the other way around.

The hole on a 5A supply looks larger than 2.1mm.

Owain