Exploitation of Initial Conditions to Achieve Flux Gain and Nondestructive Readout in Balanced Magnetic Circuits

A simple experiment on a magnetically-balanced circuit, consisting of a flux source and two equal-length parallel paths is outlined. It is observed that if a controlling signal causes one of the parallel paths to be preferred and this controlling signal is removed before switching is completed, the parallel path originally preferred continues to be preferred. The core equivalent of a balanced circuit is then examined to determine if this phenomenon is present there as well. It is found that the basic behavior of a balanced circuit and its core equivalent can be made the same, provided care is taken in setting up the same initial conditions in both circuits. It is shown that initial flux levels are important, as well as the rate at which these initial levels are established. An attempt is then made to relate, in a qualitative way, the circuit properties observed to known properties of a single core. It is observed that the properties which will be exploited here are present in most standard materials; however, a balanced circuit tends to exaggerate these properties. In Section II experiments on two balanced circuits interconnected with a 1:1 turns ratio coupling winding are described. This configuration has been found to have two stable states, the final state being dependent on the initial condition in one of the elements. Signal amplification has been achieved over at least a 4:1 range of drive currents. These results are readily explainable by reference to the element characteristics described in the first section.