Npn Transistor Amplifier Circuit Diagram. The figure below shows the basic circuit of a transistor amplifier in ce arangement. In electronics amplifiers have been used since the early twentieth century.

Common emitter amplifier circuit diagram. The most common amplifier configuration for an npn transistor is that of the common emitter amplifier circuit in the previous introduction to the amplifier tutorial we saw that a family of curves known commonly as the output characteristic curves relate the transistors collector current ic to its collector voltage vce for different values of the transistors base current ib. In active region the npn transistor acts as a good amplifier.

Consider the below figure where npn transistor is used to switch the lamp with variable resistor connected between the source and the base terminal.

In the above circuit diagram we have made a voltage divider circuit using resistor r1 and r2 of 4 7k and 1 5k respectively. We can divide the operating range of the transistor into 3 ranges. When there is light near the ldr its resistances gets low and the input voltage at base terminal is below 0 7v which is not enough to turn on the transistor. In the above circuit diagram we have made a voltage divider circuit using resistor r1 and r2 of 4 7k and 1 5k respectively.