using discharge tubes without control electrode or semiconductor devices without control electrode

Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases > without intermediate conversion into DC > by static converters > using discharge tubes without control electrode or semiconductor devices without control electrode

Conversion of AC power input into AC power output, e.g. for change of voltage, for change of frequency, for change of number of phases > without intermediate conversion into DC > by static converters (controlling transformers, reactors or choke coils, e.g. by tap changing H02P13/00) > using discharge tubes without control electrode or semiconductor devices without control electrode