| 摘要 |
PURPOSE:To reduce the number of parts in a current type inverter to decrease the manufacturing cost and to reduce the size by specifying in advance a main thyristor of a power inverter for closing an initial charging circuit. CONSTITUTION:When a start command is applied to a control circuit 7, switches SW1-SW6 are closed, and a ring counter RC is simultaneously reset, and main thyristors W, Y are fired by a power inverter 3. As a result, commutation condensers Cv, Cw, Dx, Cy are charged thereby enabling conversion of thyristors W to U and the main thyristors Y to X. When the pulse time width which is outputted from one shoot multivibrator SS is elapsed, the reset input of the ring counter RC is eliminated, the ringing operation of the counter R is started, the inverter 3 started, the switches SW1-SW6 are opened, and the circuits 5-1, 5-2 are isolated from the inverter. |
