Having problem figuring out how to know when a USB type c is disconnected from a phone. Need an alarm to go off when it is disconnected. Once a usb c is disconnected there’s no power in the connector to alarm the rest of the phone/circuit. If anyone has any ideas it would be a great help. Thank you.
Welcome to the forum.
Detecting the loss of input power in a battery powered device is most often accomplished with a simple voltage comparator circuit.
yes Paul that could get them what they want I was thinking an a App, Battery Charging Monitor you could down load however I have not seen one that has an alarm.
How would that work without sensing current.
When USB is connected the power input is at 5V when disconnected it is at 0V.
Just thought of a possible complication, USB OTG (On The Go).
Many, maybe most, phones have USB OTG which allows them to switch between working as a USB device and host.
I know very little about USB OTG, it may be that some, or all, OTG phones have 5V on VBUS all the time whether connected to a power source or not. If that’s the case a simple voltage comparator circuit won’t work.
Thank you. Just trying to figure out how it may work without using any current now.