I’m working on a wired home automation platform and I’m using ethernet cables to connect devices to it. Each cable is supplied with power for the remote device but if someone connects a bad device which somehow connects the power pins to the mains, the power would go to the automation system base and propagate to every connected device, likely destroying the entire system.
How can I isolate the power source for each port so that if a surge of power will only destroy that one port? (Note: I’m already using optoisolators for the data pins, this is just about the power source.)