ELECTRIC DRIVE Russian patent published in 2006 - IPC H02P3/24 B66C13/22 

FIELD: electrical engineering; electric drives for mobile load-lifting crane mechanisms.

SUBSTANCE: proposed electric drive has slip-ring induction motor whose rotor winding leads are connected to three-phase rectifier bridge and to starting resistor; capacitor connected to rectifier output and to two phases of power supply; current relay; two time relays; thyristor controlled by rotor current; line contactors with make power contacts in stator circuit and brake auxiliary contacts in motor control circuit that has three circuits and provides for stepless automatic transfer of electric drive from motor mode of operation to its operation as brake at desired motion speeds precluding crane tipping over.

EFFECT: enhanced safety in operation.

1 cl, 2 dwg