I got a new phone with a brick "Samsung Adaptive Fast Charging (AFC)". The Samsung AFC chargers support up to 15W (5V/2A, 9V/1.67A).
The picture comes from https://switchchargers.com/what-... with some more information.
Previously I used a 5V brick to supply power to all kinds of evaluations boards with microUSB.
As both chargers have the same USB-A it is possible to use the fast charger with old microUSB cable that was intended for 5V.
My question is: is it safe to use this fastcharger for 5V boards?
If yes, how does it work? How is guaranteed that the 5V board is not oversupplied with 9V? Or is 9V supply in stead of 5V "considered not harmfull"?
"an Orzly cable that used a 10k ohm resistor instead of the 56k ohm resistor that the USB spec demands. (These resistors don't actually meter the flow of electricity, they just tell the phone how much energy is safe to pull."
I would like to see some explanation of this resistor. May be there is something to think about if we design a board with "5V" USB supply?