555 Timer as Monostable Multivibrator

Posted on Feb 6, 2014

Are you familiar with the basics and applications of the 555 timer IC Are you looking for a book that provides all these basics If so, CircuitsToday has started an online store from where you can buy books on 555 timer IC, which have been reviewed in detail. You can go through the reviews and buy them here:- 3 Great Books to Learn 555 Timer Circ

555 Timer as Monostable Multivibrator
Click here to download the full size of the above Circuit.

uits and Projects A monostable multivibrator (MMV) often called a one-shot multivibrator, is a pulse generator circuit in which the duration of the pulse is determined by the R-C network, connected externally to the 555 timer. In such a vibrator, one state of output is stable while the other is quasi-stable (unstable). For auto-triggering of output from quasi-stable state to stable state energy is stored by an externally connected capaci ­tor C to a reference level. The time taken in storage determines the pulse width. The transition of output from stable state to quasi-stable state is accom ­plished by external triggering. The schematic of a 555 timer in monostable mode of operation is shown in figure. Pin 1 is grounded. Trigger input is applied to pin 2. In quiescent condition of output this input is kept at + VCC. To obtain transition of output from stable state to quasi-stable state, a negative-going pulse of narrow width (a width smaller than expected pulse width of output waveform) and amplitude of greater than + 2/3 VCC is applied to pin 2. Output is taken from pin 3. Pin 4 is usually connected to + VCC to avoid accidental reset. Pin 5 is grounded through a 0. 01 u F capacitor to avoid noise problem. Pin 6 (threshold) is shorted to pin 7. A resistor RA is connected between pins 6 and 8. At pins 7 a discharge capacitor is connected while pin 8 is connected to supply VCC. Initially, when the output at pin 3 is low i....

Leave Comment

characters left:

New Circuits



Popular Circuits

Mic Phantom Supply
Curtain Control Circuit
FM Broadcast Audio Transmitter
Transmission indicator
Complementary lighting control
Advantages and challenges of third-overtone IC crystals
Spring Reverb
Basic Tilt Sensor Tutorial Circuit
AMP-04 0 F 400 temperature measurement circuit
555 zinc-manganese batteries reduction charger circuit