1. An automatic degaussing apparatus for degaussing a magnetic core, comprising: sensor interface circuitry configured to receive a signal from a sensor proximate the core and to provide an output signal indicating a magnetization polarity of the core; coil interface circuitry with first and second outputs coupleable with corresponding first and second ends of a compensation coil magnetically coupled with the core, the coil interface circuitry configured to selectively individually couple the first and second outputs to a pulse voltage supply node or to a common node; and control circuitry configured to automatically cause the coil interface circuitry to selectively apply a plurality of pulses to the core via the compensation coil, and to control a polarity and an energy of the individual pulses at least partially according to the output signal from the sensor interface circuitry to at least partially demagnetize the core in a closed-loop fashion using a discrete feedback algorithm.