| 摘要 |
PURPOSE:To increase the working region of a magnetic bubble memory, by varying the holding magnetic field value by the temperature or the power supply voltage of a rotary magnetic field driving circuit. CONSTITUTION:A current is flowed to a rotary magnetic field coil L for bubble as shown by an arrow mark by means of transistors TR1 and TR2. An active element circuit is added to a driving circuit to vary the holding magnetic field value by the temperature. That is, when a TR3 is made to conduct, a right-turn current is supplied to the coil L to obtain a holding magnetic field. Then the degree of conduction is controlled for the TR3 by the output of an operational amplifier OP to which the output of a thermistor TH is supplied. Thus the holding magnetic field value is varied. Thus the working region can be increased for a magnetic bubble memory, and same effect is obtained by supplying the power supply voltage +V1 of a rotary magnetic field driving circuit to the amplifier OP to vary the holding magnetic field value. |
