555 2 seconds pulse at power up

Thread Starter


Joined Jul 2, 2010
I need help to get a two sends pulse at power up of a 555.
I did it with a Pic16, but it is expensive for just this simple task.
All i need is to get the voltage going from 0 to 5 volts at power up, stay for 2 seconds(i might change the length), then go back at zero volts after that period.
I do not have a clue about 555 - i know, shame on me - but i need help please.
Maybe a short hand drawing schematic, if i do not ask too much.
Thank you


Joined Mar 30, 2018
With the 555 timer configured to give the required 2 second mono-stable time period, add a capacitor between pin 2 and zero volts. This causes pin 2 be held momentarily low during power-up, triggering the timer.


Joined Mar 30, 2018
5V is minimum operating voltage for a common or garden 555 timer, so there should be no issue with a 5V supply.