A ball screw with a dust-proof and lubricating device comprises: a screw, a nut, a plurality of balls, an oil-absorbing member, a return unit, and two dust-proof members. The method combines the one or more desired characteristics with other preset characteristics of the transformer or the integrated circuit. Additionally, positions of the graphical representations of the consumer products relative to each other are based on multiple attributes of the products. The stacked-layer structure comprises a first coil and second coil, wherein the first coil is coupled to the second coil to suppress the common mode noise. The two contact pieces are provided in the casing and abut the two contact pieces, thereby controlling the two contact pieces to extend into the connecting positions selectively. Both of these circuits are designed to minimize demands on the signal processing engines incorporated within the voice processor, and account for very little of the on-chip circuitry.