ASTABLE MODE
Here is the post about the different working mode of 555 timer IC as I promised on the 555 timer post. An Astable mode 555 timer IC has no stable state – hence the name “astable”. That means output continually switches state between high and low without any intervention from the user, called a ‘square’ wave. This type of circuit could be used for switching a motor on and off at regular intervals. It can also be used to flash lamps and LEDs, and is useful as a ‘clock’ pulse for other digital ICs and circuits.
CONNECTION :-
Reset (pin 4) and pin 8 is connected to positive voltage (Vcc).
Resistor R 1 is connected between Vcc and the discharge pin (pin 7).
Trigger (pin 2) and threshold (pin 6) pins share a common node (means connected).
Another resistor (R 2) is connected between the discharge pin (pin 7), and the common node that is shared by the trigger (pin 2) and threshold (pin 6).
Capacitor (C 1) is connected between the common node that is shared by the trigger (pin 2) and threshold (pin 6) and GND.
Pin 1 is connected to GND.
A 10n capacitor is connected between control (pin 5) and GND.
OUTPUT
In astable mode, the 555 timer puts out a continuous stream of rectangular pulses having a specified frequency at output (pin 3).
My next post will be on monostable mode of 555 timer IC. If you find this post useful, let me know it through the comments.
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