Astable Multivibrator

AIM 

To set up an a stable multivibrator using transistors, study its performance and observe the wave form at various points.

COMPONENTS AND EQUIPMENTS REQUIRED

• POWER SUPPLY                            6 V                       1 NO
• TRANSISTOR                                 BC 548                  2 NO
•  RESISTORS                                   10 KΩ, 1 KΩ        2 NO each
•  CAPACITORS                                100μF                   2 NO
•  LED                                              GREEN, RED         1 Each
• BREAD BOARD                                                            1 NO
•  CONNECTING WIRES                                                AS REQUIRED

THEORY

Astable multivibrator is also called free running oscillator. It does not have a stable state. This circuit transits from one quasi stable state to the other and back automatically depending upon the charging and discharging time of two capacitors. When one transistor is in ON state other remains in OFF state. The collector voltage of the on transistor is approximately 0.3 V and that of OFF transistor is VCC. Suppose transistor Q1 is OFF and Q2 is ON.

PROCEDURE

1. Verify the condition of all components.

2. Set up the circuit and observe the collector and base waveforms of both the transistors.

CIRCUIT DIAGRAM

RESULT

 Observed the collector and base waveforms of both the transistor