Essay on Lab 16 Theory Of Operation

Submitted By mwithers1871
Words: 347
Pages: 2

For our final lab in this course, we have completed a two-stage RC coupled transistor amplifier by combining a common-emitter amp, which provides high voltage gain and moderate input resistance, with a common –collector amp, which offers current gain and low output resistance. As we learned earlier this semester, the primary purpose of multi-staging is to allow the a.c. signal to pass through all stages, while simultaneously isolating or blocking the d.c. conditions from one stage to the next. The end result should allow us to drive our small speaker to produce noise. In this case, we use capacitors to couple the two amplifiers. Per the schematic on the previous page, our first capacitor, C1, is in place to avoid any possible DC offset. Our resistors R1, R2, R4, R6 and R7 will provide biasing and stabilization. R4 will act as our swamping resistor. R8 will do the same in the next stage. C3 will be our emitter bypass capacitor, allowing for a low reactance path for the a.c. signal. C4 will do the same as our source bypass capacitor in the next stage. C2 is our coupling capacitor and will tie the CE and CC amps together. Additionally, it will pass the a.c. signal and act as an open to d.c. , preventing any unwanted interference or shifting Q point going into the second stage. As the a.c. signal is applied to the base of the first BJT, it is amplified across R3 and is then passed through C2 to the next stage. After the second stage, the signal is amplified further…