DIY Kit - Monostable multibivrator using transistor LGSK017 Science Project Model

Monostable Multivibrators or “One-Shot Multivibrators” as they are also called, are used to generate a single output pulse of a specified width, either “HIGH” or “LOW” when a suitable external trigger signal or pulse T is applied. This trigger signal initiates a timing cycle which causes the output of the monostable to change its state at the start of the timing cycle and will remain in this second state. We can explain the circuit easily. Whenever we turn on the power supply, the voltage at the base of Q1 gets conneced with V1 and it gets turned on. As long as Q1 remains on, V4 remains at zero voltage and hence Q2 remains off. Since Q2 is off hence capacitor C1 gets fully charged. This condition remains untill we press S2. Whenever S2 is pressed, Q2 gets turned on and capacitos gets a path to discharge itself and suddenly thhe V3 becomes negetive. Now Q1 gets turn off as negetive voltage at its base. Hence the V5 becomes high and LED D1 gets turn on. V5 remains high in the duration of discharging of the capacitor via R3. When the capacitor gets fully discharged, Q1 again gets turned on and output goes low.