Acer S2W 3300U Service Manual - Page 33

Scanner 3300U CCD Board. 5.6 Line Motor Driver Figure 5-6 The Line Motor is drived by the 2003, a unipolar motor driver. Given the clock pulses and the necessary power, it is very easy to interface with the bipolar stepping motor. 5.7 Sensor Elements The home sensor: a photo-interrupter is mounted on the CCD board to do the home positioning job, when the Scanner 4300U is calibrating or returning after finishing a scan.