I²C bus fuse

All I²C cards published so far in this magazine are normally powered by the 5 V supply in the PC via the 6-way DIN socket on the 12C PC insertion card. A drawback of this arrangement is that the 5 V supply in the PC is at risk of being short -circuited by a fault on any of the 12C cards connected. Since most pe power supplies are capable of supplying very high currents at the 5-V output (20+ A is typicall!) short-circuits can cause a lot of smoke and annoyance.