Protecting circuit against short-circuit of output terminal of AC adapter

Abstract

A protecting circuit against short-circuit of an output terminal of an AC adapter, includes a current output switching transistor in which a power source is connected to an emitter thereof and an output terminal is connected to a collector thereof, a first switching transistor which is turned on when a controlled constant-voltage is over an available range of a voltage difference between a voltage of said power source and an output voltage, a second switching transistor which is connected to be turned on when the first switching transistor is turned on, a switch control amplifier which controls a switching operation so that the current output switching transistor is turned off when a voltage of the power source is a predetermined voltage or less, and a constant-current control amplifier which controls a constant current when the second switching transistor is turned on and enters a protecting operation state.

Dependencies are inferred from the claim text.