machine with a stationary input alternating current winding which supplies the excitation, and a stationary output winding of a different number of poles in which the generated voltage at the output frequency is induced through change in field reluctance by a number of regular projections of the rotor, elektrimõõtevahend, millel on paikne ergutusseadet varustav vahelduvvooluga sisend ja erineva arvu poolustega statsionaarne väljundmähis, milles väljundsagedusel tekkinud pinge on tingitud magnettakistuse muutusest rootoril olevate korrapäraste eendite mõjul