V 1 is the battery or power supply.

electric resistance

R 1 is a resistor, which will hinder the electrification.

Voltage regulating diode

D 1 is a zener diode, which plays the role of voltage stabilization. Usually, the device has a large resistance and is non-conductive, but when the voltage at both ends is too high, it will have a critical reverse breakdown to avoid excessive voltage.

resistor

R2 is also a resistor.

capacitor

C 1 is a kind of capacitor, which can store charge and maintain a certain voltage through alternating current.

Triode

Q 1 transistor, which has the functions of amplification and switching.