Patent ID: 8035323

Claim:
A linear motor which includes a fixed primary that is divided into a number of sections, the sections being categorized into three groups, being a first group of representative sections, a second group of representative sections and a third group of ordinary sections; a translating secondary that has an operative length that is longer than any two adjacent sections of the primary; and a connecting means for connecting only those sections of the primary that are covered by the secondary to a power supply; the connecting means including an independently operable switch for each section and a control means for controlling opening and closing of the switches; the control means having a position determining means for determining which of the sections are covered by the secondary; and the control means having a current measuring means for measuring the current in the first and second representative sections with the position determining means being responsive thereto, in which the first and second representative sections alternate with at least one ordinary section from the third croup between them; and the number of ordinary sections between a first representative section and the next second representative section is the same as that between that second representative section and the next first representative section.