Detector

Amplifier

Oscillator

Modulator

Rectifier with filter

Voltage multiplier

Negative feed back

Positive feed back

Rectification

Amplification

Regulator circuits

Triggering circuits

NPN transistor

PNP transistor

Field effect transistor

Uni junction transistor

Insulating layer instead of junction

Using N material instead of P material

Using P material instead of N material

Using N material gate instead of P material