Wide PRIME-current range for all-magnetic shift registers

In an all-magnetic resistance-type shift register, a PRIME current pulse , of amplitude Ip, is applied to Npand Nbturns through the minor and major apertures, respectively. For given operation frequency , the ratio , where is the PRIME range of bistable operation, is maximized by matching so that values determined by spurious ZERO buildup and ONE dropout are the same. For a rectangular (or dc) , the matched is fixed by the core properties, and R^maxis limited (e.g., <7). However, if rises gradually, the matched depends also on the rise time Trof . The lower is, with corresponding larger Tr, the smaller is the matched , and the larger is R^max. Calculation of is carried for ramp and half-sinusoidal waveforms. The latter, for instance, at C yields R^maxvalues of 14.0 and 22.0 for of 1.0 and 0.5 kc/s respectively. Such wide PRIME ranges permit reliable register operation in a wide temperature range without resorting to temperature compensation of Ip. Experimental results are in agreement with the calculation.