okay, dumbass electrical question time
why is USB like a standardized thing but none of your shit charges when it's plugged into a computer versus a wall plug with a USB port
also is it like a different voltage or amperage or what
is it safe to just plug whatever power into your phone or
@kat Different current (colloquially called amperage); the voltage is always the same 5 V (except for things using Qualcomm quickcharge or USB-PD)
-F
@Felthry so you can just plug any current into a smartphone and it's fine??
@kat it's a voltage source, not a current source--the voltage is decided by the power supply but (up to the supply's limits) the current is decided by the phone
if it's a 2 amp power supply and your phone only needs 1 amp it'll only draw 1 amp
-F
@Felthry but if amperage is decided partly by voltage, isn't a higher voltage power source going to create higher current?
@kat yes, but all USB power supplies are 5 V (except for quickcharge and USB-PD, which start at 5 V and can increase that but only if the phone sends a special signal asking for higher voltage)
-F
@Felthry but like it doesn't matter how much current there is because it's always going to get limited by the phone which doesn't have to do anything to do that?? i'm kind of lost
@kat the current listed on the power supply is the maximum it can provide
the phone does have to do something to limit the current, but it doesn't require any communication between the phone and the power supply. there's a dedicated charger IC inside the phone that makes sure the battery is charged correctly (think of it as a chip that intelligently changes its own resistance, sort of--this is an extreme oversimplification but easy to understand, i hope)
-F
