Using this circuit diagram can be made a very simple delay circuit for power supply connection. Power supply connection delay circuit is taken directly from the network through a bridge rectifier, D1-D4. Rectifier must be able to provide current to 1 A. For safety reasons, resistor R1 provide rapid discharge of capacitor C1 to disconnect power. Its rated voltage will be 250 V AC or 400 V c.c.
As is shown in the diagram, all contacts of S1 are open, the grid of T1 is connected to the positive supply terminal (power connection, means that when the relay is activated).