Summary form only given. Proper magnetization of isotropic permanent magnets is key for their application in motors and other devices. To simplify assembly, it is often preferable to pulse magnetize "in-situ" in a fully or partially assembled device. The magnetization in isotropic magnets is determined only by the resulting field, being the sum of three components: field from the magnetizing coils, reaction field from eddy-currents in conductive fixture and assembly components, and demagnetization field in the magnet itself. Accurate analysis of pulse magnetization is a complex nonlinear problem, in which determination of transient magnetic field is coupled with pulse current in the discharge electrical circuit. A specialized magnetization solver accounting for hysteresis, eddy currents and field-circuit coupling has been developed and validated on designs of several magnetizing fixtures for isotropic permanent magnets.