| 摘要 |
PURPOSE:To be exactly operated with exact zero-cross, by providing the D-type flip-flop for load control signal input and by controlling a switch element with logic circuit output based on the load control signal output and the synchronous signal of the AC signal. CONSTITUTION:In order to supply an inductive load 27 with AC power 26, the AC power control circuit 29 consisting of thyristors is zero-cross/cycle-controlled. So far as the control gate circuit is concerned, the data input end D of the D type flip-flop FF3 is supplied with the control signal CS of the load 27 and the clock pulse input end CP is supplied with the synchronous signal SYNC synchronized with the frequency of the AC signal. As the result, the output is generated from the output end Q of the FF3 to AND circuits 21, 22, and besides the AND circuits 21, 22, at input ends, the input of the synchronous signal SYNC and the signal via an inverter 23 is generated, and the output signals OUT1, OUT2 are obtained. The conductors 1 for the thyristers are shutdown-controlled by the signals OUT1, OUT2. |
