# Pulse Delay Circuit Using 555 Timer

#### Urmil Modi

Joined Jun 17, 2018
3
Pulse Delay Circuit
Input Pulse given --> 1-2 second delay --> Output same exact pulse
Preferably without Relays

#### crutschow

Joined Mar 14, 2008
27,756
Output same exact pulse
Does this pulse width vary?
Define "exact".

#### Urmil Modi

Joined Jun 17, 2018
3
no, its just a button press, the width doesn't even matter. Basically, a button is pressed, I need it to be delayed by 1-2 seconds, and then that button pulse will be used to power a TIP31C. Also this delay must occur every time the button is pressed

#### Hymie

Joined Mar 30, 2018
991
no, its just a button press, the width doesn't even matter. Basically, a button is pressed, I need it to be delayed by 1-2 seconds, and then that button pulse will be used to power a TIP31C. Also this delay must occur every time the button is pressed
And what do you want the circuit output to do, should the button be pressed once or more times during the delay period (is this to be ignored); and what if pressed during the period that the output pulse is high?

The circuit complexity will depend on the answer to the above questions.

#### ScottWang

Joined Aug 23, 2012
7,065

#### Urmil Modi

Joined Jun 17, 2018
3
I figured it out, made 2 555 timer monostable, with different delays. made the difference between them 1 second and then used a not and an and gate to have it on after 1-second button press. Thanks anyways guys.

#### crutschow

Joined Mar 14, 2008
27,756
I figured it out, made 2 555 timer monostable, with different delays. made the difference between them 1 second and then used a not and an and gate to have it on after 1-second button press.
That will work
But typically the falling edge of the first monostable is used to trigger the second monostable.
The first thus gives the delay and the second the output pulse width.
This avoids having to add an AND gate.

#### ian field

Joined Oct 27, 2012
6,539
Pulse Delay Circuit
Input Pulse given --> 1-2 second delay --> Output same exact pulse
Preferably without Relays
AFAICR: you need 2x 555 (or 556) - the first is a monostable that triggers the 2nd, that's your delay. You probably need a C/R differentiator between them.