The working principle of common emitter amplifier circuit a

The working principle of common emitter amplifier circuit a

After the signal passes through the common emitter amplification unit circuit, it outputs an inverse amplified signal. Its working principle is shown in the figure. When analyzing, we
can consider the change curve of the input signal as the change curve of the input current . In the 1/4 cycle, the current is increasing. According to
the amplification function of the transistor IC-18IB, it can be seen that the current is also increasing. According to Ohm's law URC=ICRC, seven f. Then URC f, then from the output voltage
UR on the load RL , = VCC-URC can be obtained·sevent, URC t, Vcc remains unchanged, Uk, J. That is, the output curve is as shown in Figure 1-7 (a) . The other cycles are similarly shown in Figure (b) (c) (d). It can be seen that the output voltage is opposite in phase to the input voltage.