PURPOSE: To increase the accuracy of bit interval of write-in information, by switching the write-in current direction of magnetic head of the automatic ticket selling machine, in synchronizing with the switching timing of each exciting current of step motor and writing in the magnetic information.

CONSTITUTION: When the clock pulse P1 for exciting phase switching timing and the step motor drive signal S are fed, the AND circuit 4 supplies the exciting phase switching pulse P2 to the exciting phase switching circuit 3. The circuit 3 supplies the exciting signals aWd to the motor drive circuit 2, the step motor 1 is excited according to each signal and the tickets are carried. On the other hand, the pulse P2 is given to FF6 via the frequency division circuit 5 and the write-in information D is given to FF6. The Q, Q' outputs of FF6 are fed to the head drive circuits 81, 82, and when the output of FF6 is inverted with the pulse P2, the direction of exciting current of the magnetic head 9 is inverted, and the magnetic field is changed by this and information is written on the magnetic thin film of the ticket.