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How do I add a delay start to my 555 chip in astable mode? Answered

Hi all,

My goal is to turn 3 bulbs on in a series.
0 min - B1 on
3 min - B1 still on, B2 on
5 min - B1 off, B2 on
7 min - B1 on, B2 off, B3 on

I have decided to use 3 555 chips. May I know how can I add a delay such that their switching on and off are staggered?



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9 years ago

Picture two the diodes are arranged to perform the start of your logic
  • 0 min - B1 on
  • 3 min - B1 still on, B2 on
  • 5 min - B1 off, B2 on
You will need a 4th 555 to finish your logic.

You don't seem to have experience with the NE555 timer which can only
deliver 300ma to the bulb you have not described as yet.

I'm leaving the task of the actual timing up to you..

Pic #1 is the circuit as I found it on the web.... I then made the changes to it  to help you design it for yourself.

Read up on the 555..... click the two red pointers I have provided for you.

To start after a stipulated time takes two 555 or one 556 which is a
single IC more pins but two 555 timers in one.


Answer 9 years ago

alright, thanks a gazillion mate!


9 years ago

Add a third 555 to this schematic.

pin 3 going high is on when pin 3 goes low it starts the next 555.

Then use diode logic as shown in pic #2.  .  .  .  .   A


Answer 9 years ago

im sorry, im very new to these things.

do i need a relay coil as shown in #1?

where is the 'diode logic' in #2?

thank you for your help.


if, alternatively, i would like to use just one 555 chip and light up 1 bulb, is there a way to make it start after a stipulated time?

i.e. power on -> 5 minutes delay -> bulb begins to light and go off and on and off and on .. . .. . .. . .