Reducing coil drive power losses in magnetic bubble memory systems

More than half of the power losses in a magnetic bubble memory subsystem using field-access bubble devices can be traced to the coil drive circuitry. Linear resonant coil drive circuits tend to be very efficient, but at the expense of being more complex. Switched coil drive circuits are simple in construction, but are usually less efficient. The relative merits of these two types of coil drives will be discussed with particular emphasis on operating power efficiency. A simple technique is presented for improving the efficiency of switched coil drive circuits without increasing drive circuit complexity.