How does the circuit work?
The negative black wire is connected to the yellow wire, which in turn is connected to shorter negative side of the LED. Then the circuit moves to the longer positive side of the LED which is connected to the resistor. The resistor connects and completes the circuit by connecting to the red wire.
Why can't we see infrared?
Our biological eyes cannot see the infrared light because it is outside of our visibility.
How The Tunable Genius Light Works
The electricity goes into the yellow wire, travels into the left prong of the photoresistor, which is connected to the middle pin of the PNP transistor, controlling . . . [you know, it was kinda over his head right now. Might need to go over it a few more times].
About the PNP Transistor
The middle prong is the base, the left prong is the emitter, and the right prong is the collector. Both types of transistors act like a lever but are opposite. On the PNP transistor, positive voltage goes through the emitter and the collector when the base pin has no voltage. This will turn the LED or buzzer on. The LED or buzzer turns off when we apply positive voltage to the base pin.
Capacitor leaks current as it charges
The light goes out because when the capacitor is full, then current cannot flow through it so no current goes to the LED.
About the NPN Transistor
An NPN transistor acts like a mechanical switch, allowing electricity to flow through the emitter once electricity is applied to the base.