NUMERICAL WAVE-FORM CONTROL FOR ROTATIONAL SINGLE SHEET TESTERS

Rotational single sheet testers are imposed as measuring systems for a complete, in plane, characterisation of magnetic materials. The numer ical waveform control that drives the RSST is, despite its slow speed precise and versatile than the analogic version. Its adaptability to a lmost every induction waveform in a large frequency range makes it sui table for completely automated test procedures. The actual hardware Im plementations is reported. The existence of a variable coupling betwee n the two principal axes imposes a simultaneous correction with respec t to the flux waveform of the perpendicular axis. The magnetic circuit with airgaps hinders a simple direct relation between circuit and fie ld equations, whence the difficulty of estimating the first correction steps. The electromagnetic model and the electrical equations are dis cussed in order to determine solutions that improve numerical converge nce.