An apparatus is disclosed incorporating a plurality of light sources, such as a plurality of lighting emitting diodes, and a beam altering mechanism for altering the light projected by the plurality of light sources. Thus, the CPU and the peripheral device is operated in the maximum performance mode when the portable computer receives the power from the external fuel tank, and operated in the low power consuming mode when receiving the power from the fuel cartridge in the fuel cell, thereby enabling maximum use time of the fuel cell. The control circuit determines if lock is achieved according to the count.