In 1827, Hungarian physicist Ányos Jedlik started experimenting with electromagnetic coils. After Jedlik solved the technical problems of the continuous rotation with the invention of the commutator, he called his early devices "electromagnetic self-rotors". Although they were used only for instructional purposes, in 1828 Jedlik demonstrated the first device to contain the three main components of practical DC motors: the stator, rotor and commutator. The device employed no permanent magnets, as the magnetic fields of both the stationary and revolving components were produced solely by the currents flowing through their windings. COUNT 5
QSN1 In what year did Jedlik begin experimenting with electromagnetism? ANS1 1827 QSN2 Besides the stator and the communicator, what is an element of a DC motor? ANS2 rotor QSN3 What did Jedlik call his earliest devices? ANS3 electromagnetic self-rotors QSN4 What discovery solved the problem of continuous rotation? ANS4 commutator QSN5 What did Jedlik's improved device eliminate the need for? ANS5 permanent magnets