POLYPHASE AC/DC VOLTAGE CHANGER Russian patent published in 1996 - IPC

FIELD: electrical engineering. SUBSTANCE: voltage changer has polyphase transformer 5 with primary and secondary windings 6 and 7, respectively, rectifier 8, load 11 connected to leads 9,10, controlled rectifier 1, current sensor (limiter) 2, adjustable resistor 3 with control lead 16 using transistor 4 with additional output 17 and control input 22, leads 14 and 15 for connecting control source, and lead 12 for connecting polyphase a.c. source, polyphase rectifier bridge 13, controlled switches (resistors) 18,19, additional source 20 in the form of precharged capacitor, additional sensor or indicator, or control source 23. Novelty is introduction of current sensor (limiter) 2 and its connections, adjustable resistor 3 and its connections, second lead 16, rectifier 13 and controlled switches 18,19 and their series-connected circuits, controlled rectifier 1 made in the form of additional controlled rectifier. EFFECT: reduced quantity of controlled rectifiers and, hence, their control sources, improved utilization factor of polyphase transformer, reduced mass and size due to elimination of additional polyphase transformer, extended output signal variation range due to connecting secondary winding of polyphase transformer in delta, improved reliability of device due to limiting current at short circuits in load, transformer secondary, and rectifier. 8 cl, 43 dwg