Monostable and bistable multivibrator using IC 555 with circuit diagram :-

Monostable multivibrator using IC 555 :- 

Definition: monostable multivibrator is a type of multivibrator that has a single steady state. Mono means that the name itself indicates a state steady and a quasi-steady state. It is also known as one-shoot multivibrator.

Circuit diagram of Monostable multivibrator using IC 555

 To begin with before the triggering pulse arrives, Vout is  low ,shorting pin 7 and discharging C.

• Input pin 2 is normally held high by the 10KΩ register to trigger multivibrator a negative going pulse of less than (Vcc/3) is applied to pin2.
• This triggering makes the lower comparator high, which sets the flip flop, making Vout high opening the discharge transistor.
• Now the capacitor is free to charge from 0 volt to Vcc via RA.
• When Vc crosses the threshold 2Vcc/3 the upper comparator goes high, which reset the flip flop, making Vout low and shorting the discharge transistor.
• The capacitor discharge to 0 volt and the multivibrator is help in its stable state until another triggering pulse arrives.

Bistable multivibrator using IC 555 :-

Circuit diagram of bistable multivibrator using IC 555

For this appropriate pulse is applied to the two comparator terminal two and six in turn. The flip flop can be set and reset. The output at pin 3 can be obtained stable that is high and low. 

Schmitt trigger using IC 555