Originally Posted by
Tourist in MSN
I am not an electronic engineer, so I do not really understand this stuff. USB-A is 5 volt. USB-C appears to have at least two different voltages, with different wires in the cable, voltage as high as 20 volts.
USB-C can provide 5, 9, 15, or 20 volts. There is a protocol between the charger and the gadget so the gadget can request the voltage it wants. It might also be able to say how much current it wants. I don't know much, but I'm pretty sure what I wrote is correct.
I have some gadgets from 2020 or 2021 that charge with USB-C. If I give them more than 5 volts, they won't charge, so I need to use an old-style 5-volt charger with a A-to-C cable. Newer ones adapt to whatever the charger can deliver. My spouse just bought an iphone 15, Apple's first phone that charges by USB-C. It was interesting to see that it will take the (probably) 20 volts that a computer charger provides, and it works just fine.