25-08-2017, 09:32 PM
CE AMPLIIFIER
Aim:
To construct and test an amplifier using BJT in CE configuration with the following specifications: fL= 500Hz, fH = 60 KHz and Av = 120 and to measure its input and output impedances.
Procedure: -
1) The components were soldered on the groove board as indicated in the circuit diagram in fig12.1.
2) The D.C. Power supply was connected and the quiescent point was calculated. The quiescent point was verified to be in the active region of the transformer.
3) Input was applied through the function generator and output wave was checked so that it was not in distorted form, if amplitude distortion is there, input voltage amplitude must be reduced.
4) At different values of frequencies of input signal, output voltage was noted down and gain was calculated by the formula Av (dB) = 20log|Vo/Vi|.
5) Graph was plotted between gain in dB and frequency.
6) The 3-dB frequencies were marked on the lower and upper frequency sides.
7) The mid band frequency range, where amplification is almost constant is used for amplification purpose.