Patent ID: 7351485

Claim:
A power supply for supplying electric power to a device, the power supply comprising a power generation module, wherein the power generation module comprises: a power generation portion which generates power by using supplied power generation fuel; a plurality of fuel pack accommodating portions which accommodate a plurality of fuel packs including at least a first fuel pack and a second fuel pack to store the power generation fuel; and a control portion which controls fuel supplying such that, while the power generation fuel is supplied from one of the first and second fuel packs, the power generation fuel is not supplied from the other one of the first and second fuel packs accommodated in the fuel pack accommodating portions; wherein the control portion comprises a fuel pack locking portion which selectively locks the fuel packs in the fuel pack accommodating portions; wherein the control portion further comprises a fuel switching portion including a detection section for detecting an amount of the power generation fuel remaining in the first and second fuel packs accommodated in the fuel pack accommodating portions, and for supplying a detecting signal corresponding to the amount of the power generation fuel in the first and second fuel packs; and wherein the control portion: compares the amount of the power generation fuel in the first and second fuel packs based on the detecting signal, controls the fuel pack locking portion to lock one of the first and second fuel packs having a lower amount of the power generation fuel which is sufficient for a power generating operation, controls said one of the first and second fuel packs having the lower amount of the power generation fuel sufficient for the power generating operation to supply the power generation fuel therefrom to the power generation portion, unlocks said other one of the first and second fuel packs, judges when the amount of the power generation fuel remaining in said one of the first and second fuel packs, which is supplying the power generation fuel to the power generation portion, is less than an amount necessary for the power generating operation, based on the detecting signal, stops the supply of the power generation fuel from said one of the first and second fuel packs and unlocks said fuel pack when it is judged that the amount of the power generation fuel therein is less than the amount necessary for the power generating operation, and locks said other one of the first and second fuel packs and controls said other fuel pack to supply the power generation fuel therefrom to the power generation portion.