| 摘要 |
PURPOSE:To exercise high-speed control without permitting a large rush current to flow, by supplying a signal when a forward voltage has a minimum value within two cycles after one cycle if a signal which having from a backward voltage to a forward voltage within one cycle. CONSTITUTION:A feed command is sent out to detect the output of a circuit 5 varying from a 0 to a 1, and a pulse generator 8 generates a pulse which has 360 deg. width at the level 1. During this period, the output Q of an FF10-1 never goes to the 1 and an AND element 6-4 has an output 0, so an FF10-2 is still reset, so that a Q' is still the 1. While a forward voltage is applied to a thyristor Th1, inputs to an AND element 6-3 are both 1s by pulse generation 7-2 when an AND element 6-5 generates an output 1, a forward voltage detector 3-1 generates an output 1 and the forward voltage of the thyristor Th1 is minimized within a 360-720 deg. period after the feed command, and the output Q of an FF10-1 is set to a 1 through an OR circuit 12, sending a signal to the gate of the thyristor Th1. |
