The electric drive diagram presented above is made on the basis of several transistor type circuit breakers, GTO etc.
The bridge is built of four circuit breakers, actuated diagonally. When the circuit breakers S1 and S4 are switched on
(and S2 and S3 are switched off), Fig. 2.a, a positive voltage will be applied to the DC motor that will rotate clock
wise. By switching off the circuit breakers S1 and S4 and switching on S2 and S3, Fig. 2.b, the voltage polarity is
reversed, thus making possible the motor rotation counterclockwise.