TRANSISTOR HETEROPOLAR FREQUENCY CONVERTER THAT CONTROLS SPEED OF SYNCHRONOUS STEP MOTOR Russian patent published in 2012 - IPC H02P21/12 

FIELD: electricity.

SUBSTANCE: invention refers to the sphere of electrical engineering. A transistor heteropolar frequency converter that controls speed of a synchronous motor is designed for use in a controlled electric drive with a synchronous step motor, when supplied from a network of AC single-phase voltage. Transistors of each of three reversible transistor switches connected to a source of supply are connected in parallel. A source of supply to reversible transistor switches is a source of AC single-phase voltage. Emitters of the first transistors of each reversible transistor switch are connected to a phase of a supply network. Emitters of the second transistors of each reversible transistor switch are connected to a zero of a supply network. Collectors of transistors of the first reversible transistor switch are combined and connected to the first output of the first control winding. Collectors of transistors of the second reversible transistor switch are combined and connected to the first output of the second control winding. Second outputs of the first and second control windings are combined. Collectors of transistors of the third reversible transistor switch are also combined and connected to combined second outputs of the first and second control windings.

EFFECT: reliability improvement.