Magnetic amplifier performs analytical operations

THE CIRCUIT shown contains two saturable reactors with “square loop” cores. An alternating voltage is applied to their windings through rectifying diodes. During positive half-cycles of the supply voltage Vc the core flux of the converter stage rises from some preset value to saturation. Before “firing” only a small magnetizing current flows; after firing the supply voltage appears across the load resistance Rc and the winding resistance rc. The preset flux is determined jointly by the line voltage, which in negative (presetting) half-cycles tries to remove the core from positive saturation and by the opposing voltage of a given half-wave sinusoidal signal Vs1 1 This stage converts the waveform of the signal Vs1 into a net output waveform Vc ′ of nearly equal half-cyclic area.