Abstract: A cutting control apparatus for cutting, by a rotary type flying cutter, a sheet, pipe or like material fed by a feeder. On the basis of a synchronous cutting length corresponding to setting of a blade speed change mechanism of the flying cutter and one of a travelling speed signal of the material and the revolving speed of a blade of the cutter, a reference speed signal is produced for the other of the material travelling speed and the blade revolving speed. One of a signal related to length-measuring pulses corresponding to the distance of travel of the material and a signal related to rotation pulses corresponding to the rotation of the blade is applied as an additive input to an adder, and the other is applied as a subtractive input to the adder.

Abstract: In an AC-DC converter for converting an AC power by a six-phase, half-wave or three-phase, full-wave back-to-back or anti-parallel connection thyristor bridge to a DC power for input to a load, while the current to the load is small, the converter is actuated as a converter of a three-phase, half-wave back-to-back connection bridge, thereby to enable an alternate supply of negative and positive currents to the load. Letting the output by the AC-DC converting operation of the three-phase, half-wave back-to-back connection bridge and the output by the other converting operation be identified as main and auxiliary outputs, respectively, as the load current increases, the auxiliary output is also supplied to the load.