View Feed
group-icon
Coffee Room
Discuss anything here - everything that you wish to discuss with fellow engineers.
12940 Members
Join this group to post and comment.
Lem0nHead
Lem0nHead • May 28, 2009

missing "pulse" detector

hello
I want to do something similar to a missing-pulse-detector, but I want it to detect also steady signals
so I basically want to output high when the input is not switching up/down (up is around 1 second, down may be from 0.3s to 10s... but it doesn't need to be so exactly because it just should trigger if it's not switching for more than 15 seconds)

I'm trying to avoid using a microcontroller, so maybe 555 can do that?

input:
_--_--___--_--______________--___--_-----------------_--_--

output:
______________________-----_________________------______
Harshad Italiya
Harshad Italiya • May 29, 2009
So you want to monitoring the Input Pules Continue?
Lem0nHead
Lem0nHead • May 29, 2009
godfather
So you want to monitoring the Input Pules Continue?
yes
summarizing
the output should go high if the input is steady high or low for more than 15 seconds
then the output goes down again when it switches
Harshad Italiya
Harshad Italiya • May 29, 2009
Why not you use Microcontroller is there any restriction?
Lem0nHead
Lem0nHead • May 29, 2009
godfather
Why not you use Microcontroller is there any restriction?
no
I just find it easier if it's possible with one or two 555, if it's possible
otherwise I'd need to get a programmer board and learn to program
Harshad Italiya
Harshad Italiya • May 29, 2009
yes let check out first that is it possible with 555 or not... and one more thinh buddy programming of Controller is not too much difficult.

Share this content on your social channels -