The following diagram is the circuit diagram of the very basic monostable multivibrator which built based on timer IC 555.
R1 = see notes
C1 = see notes
C2 = 10nF
IC1 = LM555
- R1 and C1 determine length of output pulse where t=R1xC1 and R1 is in ohms and C1 is in farads.
- Pin 4 is the RESET. Leave it connected to power supply (+V) during normal operation. Bring pin 4 AND pin 2 low at the same time to reset timing cycle.