A high-speed NDRO analog memory using electrodeposited permalloy wires

An NDRO analog memory was constructed with an electrodeposited Permalloy wire and tested to demonstrate that high speed, low power, and high stability are realized. The interrogation copper wire is wound around the deposited wire, and the wire is driven along the hard axis by a 225-kHz sinusoidal field. The center copper wire, on which Permalloy was deposited, is used for the memory setting and sensing the level. The output signal is a 450-kHz sinusoidal wave, and the amplitude is proportional to the flux level. The flux level was found to be set by means of the pulse field as short as 100 ns. The output signal is quite small, but it is stably amplified using a tuned amplifier because of the definite frequency of the signal. Furthermore, some experiments on operational mode and flux reversal were performed, and the results are discussed.