13-09-2013, 02:42 PM
ASTABLE MULTIVIBRATOR
Aim:
To design and construct an astable multivibrator using transistor and to plot the
output waveform.
Theory:
Astable multivibrator is also known as free running multivibrator. It is
rectangular wave shaping circuit having non-stable states. This circuit does not need an
external trigger to change state. It consists of two similar NPN transistors. They are
capacitor coupled. It has 2 quasi-stable states. It switches between the two states without
any applications of input trigger pulses. Thus it produces a square wave output without
any input trigger. The time period of the output square wave is given by, T = 1.38RC.
Procedure:
Connections are made as per the circuit diagram.
Switch on the power supply.
Note down the output TON, TOFF and output voltage from CRO.
Plot the output waveform in the graph.
RESULT:
Thus the astable multivibrator is designed and constructed using transistor and its
output waveform is plotted.