On the dynamic properties of cascaded self-saturating magnetic amplifiers

The influence of some parameters of the 2-stage self-saturating magnetic amplifier on its steady-state and transient properties is described. It is shown that applying an filter between both stages ensures proper operation of the amplifier. On the basis of the difference equations describing the single stage self-saturating magnetic amplifier, the discrete transmittance of the circuit can be derived. It is pointed out that the back reaction of the second stage on the first appears in cascade. The time constants of the cascade are not equal to the time constants of stages working separately. The influence of the electric and magnetic feedback loop over both stages on the stability of the circuit is considered. There are given conditions under which, when the transient state is caused by a jump change of control voltage, the cascade output voltage appears as an exponential function with two time constants, damped oscillations, or self-sustained oscillations. Characteristic parameters of the cascaded magnetic amplifier are determined. Theoretical results were compared with laboratory investigations.