This description describes wagering game systems that include docking stations. The certifier device includes a scanner for scanning the original document to generate a true copy image. This however is not effective when the motion in the image sequence is not linear. And, the switching signal generator is connected to the first and second switch-controlled sampling circuits for providing a first and a second switch control signals, adjusted to have a phase difference near ninety degrees, to the first and second switch-controlled sampling circuits respectively for demodulating the modulated input signal. The first receiving groove is used to receive the head. The processor adjusts the at least one predetermined characteristic based on the comparison, and adjusts the braking schedule based on the adjustment to the at least one predetermined characteristic.