MONOSTABLE MODE :-
As I promised here is the post on monostable mode of 555 timer IC. In this mode, the 555 timer functions as a “one-shot” pulse generator. The name “monostable” meaning “one stable state”.
APPLICATION :-
Applications include timers, missing pulse detection, bouncefree switches, touch
switches, frequency divider, capacitance measurement, pulse-width modulation
(PWM) and so on. For example monostable 555 circuit is ideal for projects at exhibitions, which needed to work when a visitor pushes the button to start the project’s mechanism moving, and the mechanism will automatically switch off after the time you set.
WORKING OF MONOSTABLE 555 TIMER
In this mode 555 acts as a pulse generator and the pulse starts when the 555 timer receives a input at the trigger input (pin 2) that falls below a third of the voltage supply.The width of the output pulse is determined by the time constant of an RC network, which consists of a capacitor (C) and a resistor (R). The output pulse ends when the voltage on the capacitor (C) equals 2/3 of the supply voltage( Vcc). The output pulse width can be lengthened or shortened to your need just by adjusting the values of the capacitor (C) and a resistor (R).
CONNECTION :-
Reset (pin 4) and pin 8 is connected to positive voltage (Vcc).
Discharge pin (pin 7) and threshold (pin 6) pins share a common node (means connected).
Resistor R is connected between the Vcc and the common node that is shared by the discharge pin (pin 7) and threshold (pin 6).
Capacitor C is connected between the common node that is shared by the discharge pin (pin 7) and threshold (pin 6) and GND.
Pin 1 is connected to GND.
A 10n capacitor is connected between control (pin 5) and GND.
Here is all about monostable mode of 555 timer IC. My next post will be on bistable mode of 555 timer IC. If you have any doubts or you like the post, put it in the comment box below.
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