Smooth on and off car interior lighting

Hello guys! you probably saw in the car how smoothly the lights go out! so today we will collect and test this circuit! and here it is, consists of several radio components, of which 2 active are transistors, one is bipolar, the other field)

The principle of operation is the smooth opening and closing of transistors. Opening speed depends on resistor R3 and capacitor C2. And the closing speed from the resistor R4 and the capacitor C2.

Link to the archive with the printed circuit board - Download