| 摘要 |
PURPOSE:To prevent the occurrence of an eddy current and improve the reliability by putting the timing of changeover in the position where a minute angle is added to an integer times 60 deg. of a modulated wave, when changing over the magnification of carrier frequency to modulated frequency in order. CONSTITUTION:A rate multiplier 22 makes the output of a latch circuit 21, which latches inverter frequency Finv, into proportional clocks CKFinv, and a counter 23 counts them, and it outputs them, after converting them into electrical angles theta. Bit theta 60 equivalent to 60 deg.Xn of output is inputted into the K port of a delay flip flop 28, and a minute angle theta is inputted into the CK port, and the output Q is given to the CK port of the of a latch circuit 26, and a changeover signal to change over a pulse mode N is outputted to a pattern ROM 24. The pattern ROM 24 receives a pulse mode command N from the latch circuit 26, and changes a trapezoid wave over to a carrier wave e and outputs it, and a comparator 25 compares it with a modulated wave em of the latch 27, and outputs a pulse gate signal G, according to the condition. |
