| 摘要 |
PURPOSE:To change electric power impressed upon a load through the opening and closing of a changeover switch, by installing a diode in series to the primary winding of a transformer and the changeover switch in parallel with the diode. CONSTITUTION:The primary winding 14 of a transformer 13 is connected to a power source 10 through a diode 18 and switch 19 connected with the diode 18 in parallel. While the switch 19 is closed, a voltage is induced across the tertiary winding 17 to both directions of the AC when a switch 16 which is near at hand is turned on, and a thyristor 12 is triggered. On the other hand, when the switch 19 is opened, the thyristor 12 is triggered by a half-wave only, because only the half-wave which passes through the diode 18 is induced in the tertiary winding 17. Therefore, electric power which is equal to the half-cycle of the AC is impressed upon a motor driven blower 11 which is a load. When such an arrangement is made, electric power impressed upon a load can be changed through the opening and closing of the switch 19. |
