Small-signal parameters. Basic operating principles of devices. Diodes: rectifier diode, P- i- N diode, high frequency diode, impulse diode, tunnel diode, backward diode, light emitting diode, laser diode, stabilitron, varicap. Bipolar transistors and field-effect transistors. Charge-coupled devices. Thyristors. Photo resistors, diodes, transistors, thyristors. Optrons. Photoelectric multiplicators. Cathode ray lamps, kinescopes. Displays. Noise.