Direct current welding electric power source device

Abstract

Abstract PURPOSE: To decrease the weight and size of the device and performs its economical output controlling by enhancing the use frequency of a main transformer with an inverter circuit of sufficiently decreased frequency variable range which performs output change and decreasing the weight of the main transformer and reactor. CONSTITUTION: A transformer Tr is connected as load of the inverter part to which direct current inputs and the secondary side output thereof is full-wave rectified by way of an AC reactor L 1 . Arc load is connected between their outputs. As a result of this, the full-wave rectified output decreases or increases with an increase or decrease in the inverter frequency, but if this frequency is made sufficiently larger than the commercial frequency, the commutation loss of the inverter part becomes large. Because of this, the variable range of the foregoing frequency with respect to a desired ouput range is made much smaller. Namely, the inverter quiescent time when the switching elements Q 1 WQ 4 to obtain minimum outputs are all turned OFF is made slightly less than half the period of the maximum inverter frequency and this set time is employed in a much lower frequency region, whereby the output is made constant. COPYRIGHT: (C)1981,JPO&Japio

Inventors

• 👤 Yoriaki Nishida
• 👤 Hisao Tsunaga

Bibliographic Details