Patent ID: 8654463

Claim:
A device for controlling a bit density of a magnetic card, comprising: a prime mover for providing power required by driving the magnetic card to move relative to a recording magnetic head or driving the recording magnetic head to move relative to the magnetic card; a transmission mechanism for transmitting the power outputted by the prime mover to the magnetic card or the recording magnetic head correspondingly; a CPU for sending related information of magnetic recording via a data/address/control bus, with the related information including data information, address information, and control information; a track data encoder for receiving a magnetic writing pulse signal and the related information for achieving synchronization and encoding the data information in the case of synchronization of the magnetic writing pulse signal, to form magnetic writing data, wherein the magnetic writing data comprises a timing bit and a data bit; a magnetic head driving circuit for receiving the magnetic writing data and outputting a magnetic writing control signal according to the magnetic writing data, wherein the magnetic writing control signal is used for controlling electric current variation of a coil of the recording magnetic head so as to control flux transition; and a frequency divider for dividing frequency of a driving pulse signal of a stepper motor according to a divider value and then outputting the magnetic writing pulse signal, wherein the divider value is predetermined according to the bit density required by the track, wherein the prime mover comprises the stepper motor, in which frequency of the magnetic writing pulse signal and frequency of the driving pulse signal of the stepper motor is in a linear relationship.