Voltage converter with GTO thyristors in series connection with {HEAD ~ at least a choke} with {TAIL ~ freewheeling circuit} 
Voltage converter with GTO thyristors in series connection with { HEAD ~ at least a choke } with { TAIL ~ freewheeling circuit }
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL