| 摘要 |
PURPOSE:To alleviate power loss by a main circuit transistor and its base drive circuit by interrupting the ON, OFF commands of the main circuit transistor when anti-parallel connection diodes are conducted. CONSTITUTION:A current command is converted by a transistor circuit 17 to a rectangular wave corresponding to positive and negative polarities provided with a small time lag at the rise. A current command and a current feedback signal are compared, and the output obtained by passing a current regulator is compared by a comparator 2 with a carrier triangular wave from an oscillator 7. The output of the comparator 2 is applied to an AND gate 18, and through a code converter 8 to an AND gate 18, and AND-calculated with the rectangular wave from the selector 17. The outputs of the gates 18, 19 are applied to base drive circuits 9, 10, and upper and lower transistors 3, 4 are turned ON or OFF. |
