Hi, I have two circuit diagrams. One circuit someone else designed using two NPN and one PNP transistors and it amplifies a signal to fade on an arrangement of LEDs. I changed it so the values of the resistors is probably no longer suitable. I don't know why they used a PNP transistor instead of using three NPN transistors so I drew the second circuit diagram which I think would do the same thing but I don't know enough about electronics to be confident. Can someone else advise why to use a PNP transistor?