Patent ID: 8884627

Claim:
An apparatus for detecting a short-circuit of output diode in a converter, used in a power-supply system that comprises first and second converters capable of stepping up an input direct-current voltage from a direct-current power supply to output a post-step-up voltage via an output diode, wherein the output ends of the first and second converters are connected in parallel to each other, the apparatus comprising: a first voltage monitoring unit configured to monitor input direct-current voltage of the first converter; a second voltage monitoring unit configured to monitor a post-step-up voltage of the second converter; and a judgment control unit configured to judge that an output diode of the first converter is short-circuited, when the input direct-current voltage monitored by the first voltage monitoring unit rises up to the post-step-up voltage stepped up by the second converter during a step-up operation of the second converter, measured by the second voltage monitoring unit.