Circuit arrangement for controlling the power supply to an electrothermal cutting apparatus

摘要

The circuit arrangement (1 to 4) serves for controlling the power requirement of an electrothermal cutting apparatus (5) for cutting webs of fusible synthetic woven fabrics, in particular on weaving machines, the power for the cutting apparatus (5) being set automatically to a low value during a temporary standstill of the machine and back to a higher value upon starting. For this purpose, circuits (2, 3) operating by the phase control method are provided with adjustable timing elements (12 to 15 and 16 to 18, respectively) and a switching device (10, 10k) which is actuated by the drive of the machine and by which, when the machine is running, the time constant of the timing elements (12 to 15 and 16 to 18), determining the firing angle, is reduced and, as a result, the power through the cutting apparatus (5) is increased.