Magnetic analog memory elements of a single core

The behavior of an analog memory element using a single toroidal magnetic core with rectangular hysteresis loop is presented. In this element, flux levels stored in the core as analog information can be nondestructively and continuously read out. With the application of a slight, amplitude-modulated, radio frequency (RF) field, the modulation frequency component of the induced voltage waveform is detected as an analog output signal. The principle of operation requires only one core per memory element, so that problems of mismatching of two cores, which appear in a second-harmonic type element, are completely eliminated. Experimental results show that this is suitable as an analog memory element, and that the eddy-current effect enhances the output signals.