# Help with a pulse delay circuit

#### Jbble

Joined Sep 18, 2021
2
I'm trying to figure out how to delay a variable input (through a pushbutton or other) and get the same length of pulse a set time later(1-2 seconds). Like this:Some things I've tried have been these:
Delay before turn on circuit
Delay before turn off circuit
Delayed Start circuit

So far the Delayed Start circuit has been the closest thing to what I need, as it is from a pushbutton, but it turns off as soon as the pushbutton is released, which is a big problem. This is running on 5v DC if that helps. An equation to calculate how long the delay will be would be awesome as well if possible. Sorry if this isn't enough information, I'm new to electronics and such.

#### ericgibbs

Joined Jan 29, 2010
16,837
hi Jb,
Welcome to AAC.
Post a circuit showing what you have built for this delay project.
E

#### LowQCab

Joined Nov 6, 2012
2,668
We need to know what the end result is supposed to be
otherwise everything is speculation.
What overall problem are You trying to solve ?
What or where is the Input coming from ?
What is the Output driving ?
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#### MrChips

Joined Oct 2, 2009
27,731
Sorry, what you are attempting to do has no easy solution.
Hence you need to rethink why you need to do this.
You need to answer the questions in post #3.

#### Jbble

Joined Sep 18, 2021
2
The end result is supposed to LEDs in a ring that cycle through on and off states with a 1 second delay between them. Like this:
The other solutions I've seen are shift registers, but I couldn't figure out how to use those for this either. I do have two 74HC959's and two 74HC164's. Right now I'm just powering this through the 5v pins of an Arduino, but in the future I would like to power it from a 9v battery and a voltage regulator to get 5v out. I realize now the shift register solution might be the easier one.

#### MrChips

Joined Oct 2, 2009
27,731
Are the pulse widths expected to be different?
If the answer is yes then you have to determine the length of the shift register versus the clock cycle in order to obtain the optimum clock frequency.

#### sghioto

Joined Dec 31, 2017
3,718
Right now I'm just powering this through the 5v pins of an Arduino.
I realize now the shift register solution might be the easier one.
Why not just program the Arduino to do this?

Joined Jan 15, 2015
7,088
Why not just program the Arduino to do this?
That would be my question also. You can do this with discrete components easy enough but it can be done much, much simpler using just 4 digital outputs of an Arduino or any similar uC. You also easily have the option of changing the timing and sequence easily. Early versions of what you want were commonly called LED chaser circuits. A google of LED Chaser Circuit should bring up a dozen hits. Remember you do not need a full Arduino, there are plenty of easy to program PICAXE chips out there that would do just fine. Either choice results in very little and simple programming skill.

Ron

#### djsfantasi

Joined Apr 11, 2010
8,684
As a suggestion, an ATTINY85 could do this. And be programmed with the Arduino IDE and a programmer, such as the one from Sparkfun.