Patent ID: 8040643

Claim:
Power supply switching apparatus comprising: an output switch for supplying power from a power supply to a load connected to an output terminal; a driver for controlling turn-on of said output switch; and a control signal generator for controlling said driver to produce a desired progressive turn-on characteristic, said control signal generator including an overload detection circuit responsive to a parameter of the load relative to a reference signal to provide a first fault signal in case of detection of an overload condition after a turn-on phase of said output switch, wherein said control signal generator is responsive to said reference signal to activate said overload detection circuit to respond to an overload condition at said load and provide a second fault signal at least during said turn-on phase of said output switch even in presence of a severe overload condition at the output terminal, wherein said overload detection circuit comprises a first detector activated at a first voltage for detecting resistive overload and a second detector activated at a second voltage different from said first voltage for detecting the severe overload.