| 摘要 |
A magnetic bubble driving device produces a rotating magnetic field for a magnetic bubble memory unit by using two coils wound orthogonally to each other and cylindrically around the memory unit and by using driving circuitry for driving the coils with trapezoidally-shaped currents which are 1/4 period out of phase with each other. A novel switch control mechanism is provided to produce efficient periodic coil currents by non-resonant circuit means. Each drive coil is connected to terinals T1 and T2 of a four terminal electrical bridge network (T1, T2, T3, T4) wherein each leg comprises a parallel coupling of a switch and a clamping diode and wherein an external source of potential is applied across terminals T3 and T4. Each switch opens and closes independently under the influence of a separate control signal. In one embodiment, a delay element and an OR-gate are used to derive the separate electrical control signal of one switch from the control signal of another switch. In another embodiment, control signals for each switch are separately stored in digital form at different storage locations of a read only memory (ROM).
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