Patent ID: 7224562

Claim:
A short-circuit protective circuit comprising: a regulator having an input terminal connected to a specific power-supply line among a plurality of power-supply lines, an output terminal for outputting a constant voltage and an output control terminal for turning on or off the output of said regulator; a plurality of constant-voltage circuits connected to each power-supply line other than said specific power-supply line, each of said constant-voltage circuits supplying a constant voltage for each power-supply line based on the constant voltage supplied from said output terminal of said regulator; a plurality of voltage detection circuits connected to each power-supply line other than said specific power-supply line for detecting a voltage drop at any output side thereof and outputting a detection signal; and an operation circuit connected to said output control terminal of said regulator for stopping the output voltages of said constant-voltage circuits all at once, by stopping the output voltage from said regulator in response to said detection signal outputted from said voltage detection circuit.