| 摘要 |
PURPOSE:To operate a magnetic bubble memory device over a wide temperature range and to improve the quality and the reliability by providing a bias magnetic field generating coil beside a permanent magnet, and changing the current in accordance with temperature to set a bias magnetic field in the center of the operation range of the magnetic bubble memory device. CONSTITUTION:A bias magnetic field generating coil 6 is provided beside the permanent magnet. When the temperature rises and the resistance value of a thermistor 14 is reduced, the base potential of a transistor TR12 is raised, and a current is not flowed to the coil 6. Meanwhile, when the temperature falls and the resistance value of the thermistor 14 is raised, the base potential of the TR12 falls, and a current is flowed to the coil 6. Thus, the magnetic bubble memory device is operated over a wide temperature range to improve the quality and the reliability if the bias magnetic field is set in the center of the stable operation range for temperature. |
