| 摘要 |
PROBLEM TO BE SOLVED: To resolve the problem of a conventional semiconductor power converter such as that the controllability drops if the converter drives the element of a voltage bridge circuit with a gate signal, giving it a dead time. SOLUTION: A current code detecting circuit DET judges the positive and negative polarity of the current iac on AC side of a voltage bridge circuit. Logical product circuits G1 and G2 and an inverting circuit G3 performs logical product operation between the original gate signal to complementarily turn on or turn off elements SP and SN with dead time 0 and the detected code of a current code detecting circuit, and supplies only the element SP with a gate signal when the detected code of the detecting circuit is positive, and supplies only the element SN with a gate signal when it is negative. Moreover, this converter supplies the element on the side where an AC current flows with a gate signal, waiting for a dead time, when the current code detecting circuit detects the change of positive and negative polarity of the AC current, and further this gives it a dead time for only a required time only in the case where the dead time is required, and the current code detecting circuit has hysteresis. |
