oscillators:

Oscillators: What Are They? (Definition, Types, & Applications)

50+ Electrical and Electronic Components Symbols
Basic Electricity | Four Basics of electricity there
What is a AC Motor? Definition & Types
Difference Between Real Image and Virtual Image
What is a PNP Transistor? Symbol, Construction, Working Principle
Oscillators: What Are They? (Definition, Types, & Applications)
Thyristor or Silicon Controlled Rectifier (SCR) Introduction, Working and Applications