Comments on: Basic Monostable Multivibrator based IC timer 555 https://electronicscheme.net/basic-monostable-multivibrator-based-ic-timer-555/?utm_source=rss&utm_medium=rss&utm_campaign=basic-monostable-multivibrator-based-ic-timer-555 Schematic Diagram & PCB Design Mon, 29 Sep 2014 06:21:37 +0000 hourly 1 By: Vanangamudiyan https://electronicscheme.net/basic-monostable-multivibrator-based-ic-timer-555/#comment-121637 Thu, 22 Sep 2011 01:37:41 +0000 http://electronicscheme.net/?p=351#comment-121637 @edgard you were right dude. i’ve experienced the problem. it is called the pull up resistor that pulls the level of pin 2 to low when the switch is pressed and maintain at high when the switch is open. with the resistor when the switch is open the pin2 floats.

Here is neat explanation on the operation of monostable multivibrator using ic555.
http://yengal-marumugam.blogspot.com/2011/09/monostable-multivibrator.html

]]> By: edgard https://electronicscheme.net/basic-monostable-multivibrator-based-ic-timer-555/#comment-5321 Tue, 06 Jul 2010 02:36:39 +0000 http://electronicscheme.net/?p=351#comment-5321 This circuit need a resistor of 10k between pin 2 and positive (pin 8)to polarize it.
Without it, the circuit does not work, the out stands always in high level.
(My English is poor, I know it).
Adding this resistor the circuit works properly and is very useful.

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