a linear actuator comprising a spindle , a spindle nut , a transmission , an electrical motor , and an actuation element , is arranged to linearly move the actuation element by means of an interaction of the spindle and the spindle nut , which interaction is being driven by the electrical motor through the transmission . a position of the actuation element , the relative position between spindle and spindle nut , is determined by means of an absolute rotary position sensor and a counter . the counter keeps track of the number of under - flows and over - flows the absolute rotary position sensor generates during movement of the actuation element . a combination of a value from the absolute rotary position sensor and a count from the counter determines the position .