This paper describes a technique for the simulation of complex magnetic systems intimately connected to any necessary drive electronics. The system is split into two Kirchhoffian domains, one magnetic and one electric. Two-way interaction between the domains is supported by a virtual device called a magnetoelectric differential gyrator. With this technique, arbitrarily complex, nonlinear, hysteretic magnetic systems may be simulated in the time domain, coupled to any appropriate nonlinear electronics, at a fraction of the cost of a comparable finite-element calculation. The capabilities of the system are demonstrated by the simulation of a feedback-controlled current-sensing system, and the simulation tracks the measured behavior of the system well outside its linear region, to the point that the nonlinear hysteretic core is being driven into and out of saturation, a consequence of a time delay inherent in the electronics. This is compared with a conventional electronic simulation of the same system, and the increased accuracy of this technique is clearly demonstrated.