| 摘要 |
PURPOSE:To enable optional adjustment of a set time, by providing a delay circuit in which an H signal is supplied to a first output terminal and an L signal is supplied to a second terminal simultaneously with the switching-on of a power source and these signals ae inverted after a prescribed time. CONSTITUTION:A power source 1 is connected to a delay circuit 11 comprising an oscillation circuit 12, a frequency division circuit 13, a counter circuit 14 and an automatic reset circuit 16. A first relay 24 is coupled to the output terminal 21a of the delay circuit. A second relay 36 is coupled to the output terminal 21b of the delay circuit through an integration circuit 33. When the power source 1 is switched on, the delay circuit 11 is reset. At that time, an H signal is supplied to the terminal 21a, an L signal is supplied to the terminal 21b, the first relay 24 is energized and Y-connection is effected. After a prescribed time, the output of the delay circuit 11 are inverted, the second relay 36 is energized and delta connection is effected. According to this constitution, a set time can be optionally adjusted and both the relays are prevented from being simultaneously driven at the time of changeover. |
