Transient response of magnetic amplifiers

THE TRANSIENT RESPONSE of magnetic amplifiers with cores of gradually varying incremental permeability can be analyzed with methods already applied in previous articles. For this, the alternating component of core fluxes is assumed to vary sinusoidally and the normal magnetization curve is approximated by a hyperbolic sine function of the type H = U sinh uB. A straightforward integration of the differential equations of the control circuits for a step change of the signal voltage becomes hereby possible, at least for “slow” transients lasting over a few cycles of the a-c source frequency, and curves representing the output current (rms or rectified average) during the transient can be calculated.