If You Want to switch on any Load After Some Moment Or Some Duration Then You Can Use this Timer Circuit. This is Tested . Timing Can be Adjusted By Adjustment of Preset.
This circuit is very useful in Protection of Any Load . A Device Can be Damaged By the Sudden Unstabilized Current or Voltage flow Through Whole Circuit. Some time Mains Voltage Take Some Moment to Stabilization .
So If You Connect a Delay Timer ,then Timer Stops The Current Flow For A Fix Duration, and After That It Allow To Pass The Current.
2N2222 is more suitable At the place of Q2