| 摘要 |
PURPOSE:To control the deviated exitation of a transformer by sample-holding the output current of the high frequency power source immediately before a switching element being turned off separated in positive and negative and by error-amplifying the difference and by making it possible to control the electrifying width of the switching element. CONSTITUTION:The output current i1 of a high frequency power source immediately before a switching element 3a, 3a', 3b, 3b' being turned off is separated respectively to a positive and negative and sample-held by a sample-holding circuit 11a and 11b of a control circuit 5 incorporated in a power source device 1 which a current i2 of welding machine is sent to with rectifying a high frequency output via a transformer 7. The difference is then amplified and the electrifying width of elements 3b, 3b', 3a, 3a' is controlled and the deviated exitation of the transformer 7 for welding machine is controlled. |
