Amplifier architectures are provided for current sensing applications. The integrated services digital network private branch exchange comprises a plurality of trunk chips, a plurality of subscribe chips, and a plurality of priority selection circuits. The fan assembly includes an enclosure defining a chamber and an opening at a side wall thereof, along with a blower received in the chamber. This assembly is provided to the user. A micromachine having a complicated member such as a diagram which is made of a single-crystalline material can be easily manufactured through no junction. The first and second conveyers are operable to drive main drive rollers provided at start ends of the conveyers by bringing the rollers into abutment against side surfaces of rearmost pallets in the advancing direction, thereby urging and collectively driving a plurality of pallets which are connected together forwardly of the rearmost pallets in a state in contact with the rearmost pallets.