Touch switch power circuit

The induction automatic switch circuit is shown in the figure. It can be placed at the entrance of the corridor
. When someone comes in, the street light will automatically light up. After a certain delay,
the light will automatically turn off. The delay time can be adjusted through RP, ranging from seconds to minutes. The sensing
piece G is a metal piece. The larger the area, the higher the sensitivity.
There is no need for external resistors and external transistors on the small printed circuit board of the musical piece .