| 摘要 |
PROBLEM TO BE SOLVED: To reduce the cost, eliminate the necessity of a gain adjustment, and increase the responsibility to the result of line current detection conducted following a line current command by giving a cyclical state renewing timing to a logic circuit which generates a switching comand signal for each main circuit switching power device. SOLUTION: A logic circuit 10 receives a first, a second, and a third line current comparison result HU, HV, UW and, at the same time, it receives a state renewing timing signal CLK 10 from a timing generating means 11. Then, the logic circuit 10 outputs a first, a second, and a third switching command signal PU, PV, PW for commanding the turn on/off of main circuit switching power devices Q1, Q2, Q3, Q4, Q5, Q6. The logic circuit 10 renews the state based on the signal levels of the first, the second, and the third line current comparison result HU, HV, HW at the timing of the edge of the rise of the state renewing timing signal CLK 10 and then renews the switching command signals PU, PV, PW. |
