Astable Multivibrator Using Transistor. The resistance r should be designed to limit the collector current ic with in a safe limit. The astable multivibrator is another type of cross coupled transistor switching circuit that has no stable output states as it changes from one state to the other all the time.
Astable multivibrator using transistors working. When one transistor is in on state and other remains in off state. The astable circuit consists of two switching transistors a cross coupled feedback network and two time delay capacitors which allows oscillation between the two states with no external triggering to produce the change in state.
It is also called free running relaxation oscillator.
With no external signal applied the transistors alternately switch from cutoff to saturation state at a frequency determined by the rc time constants of the coupling circuits. When the circuit is switched on one transistor will driven to saturation on and other will driven to cutoff. How this circuit works is through the rc network of the resistor and capacitor. The resistance r should be designed to limit the collector current ic with in a safe limit.
