Patent ID: 8169755

Claim:
A power supply system comprising: a generator which is driven by an internal combustion engine or other power source; a generator controller which controls an amount of electric power generated by said generator based on an output voltage from said generator; a first power source apparatus which is charged by the electric power generated by said generator; a DC converter which converts the electric power generated by said generator; a second power source apparatus which is charged by the electric power converted by said DC converter; an electric load which is operated by the electric power converted at said DC converter; an input/output short-circuit detector which detects a short-circuit between an input of said DC converter and an output of said DC converter due to a fault in an internal part of said DC converter; and an open-circuit fault detector which detects an open-circuit fault at a positive pole or negative pole of said first power source apparatus, wherein said second power source apparatus and said electric load comprise a load circuit arrangement, wherein when said input/output short-circuit detector detects a fault of said DC converter, said input/output short-circuit detector instructs said generator controller such that said generator is switched to generate power at a predetermined constant voltage which is determined based on a voltage of said load circuit arrangement, and wherein when said open-circuit fault detector detects a fault of said first power source apparatus, said open-circuit fault detector instructs said generator controller such that said generator is switched to generate power at a predetermined constant voltage which is determined based on a voltage of said load circuit arrangement.