Sonsivri
 
*
Welcome, Guest. Please login or register.
Did you miss your activation email?
December 10, 2016, 05:31:27 17:31


Login with username, password and session length


Pages: [1]
Print
Author Topic: Missing pulse detector help  (Read 2694 times)
0 Members and 1 Guest are viewing this topic.
hogar
Newbie
*
Offline Offline

Posts: 28

Thank You
-Given: 7
-Receive: 13


« on: December 10, 2008, 09:01:52 21:01 »

   
Help me with detectors pulse from 4 independent sources for 2-4 seconds with a beep and automatically reset when the pulses repeat again
If someone has an idea ....

Thanks in advance
Logged
Parmin
Hero Member
*****
Offline Offline

Posts: 544

Thank You
-Given: 357
-Receive: 126


Very Wise (and grouchy) Old Man


« Reply #1 on: December 10, 2008, 11:07:30 23:07 »

use watchdog timer on a PIC, do a CLRWDT on pulse and a beep when WDT trip.
Logged

If I have said something that offends you, please let me know, so I can say it again later.
hogar
Newbie
*
Offline Offline

Posts: 28

Thank You
-Given: 7
-Receive: 13


« Reply #2 on: December 11, 2008, 12:58:07 00:58 »

   
Thanks, but I'm not good with PIC need something "older" or a little more help,actually a lot of help
   
If you have the will and time....
Logged
itp
Junior Member
**
Offline Offline

Posts: 58

Thank You
-Given: 189
-Receive: 20


« Reply #3 on: December 11, 2008, 05:47:47 05:47 »

Hi hogar,

If I understood your problem correctly , you can use a re-trigger able mono-shot with 2 to 4 Sec delay. Re-trigger this mono shot by the pulses in your problem. If this trigger pulses misses  the mono-shot will no longer will get trigger and it will change the state. This state of the mono-shot can be used to trigger your alarm circuit. Hope I am clear.
Regards
Itp
Logged
jzaghal
V.I.P
Active Member
*****
Offline Offline

Posts: 147

Thank You
-Given: 355
-Receive: 49



« Reply #4 on: December 11, 2008, 01:27:53 13:27 »

Hi,

Try investigating the popular 555 Timer. It is sometimes used as a Missing Pulse Detector.

Hope this helps.

Bye.
Logged
hogar
Newbie
*
Offline Offline

Posts: 28

Thank You
-Given: 7
-Receive: 13


« Reply #5 on: December 11, 2008, 08:15:54 20:15 »

I need the following:
If the pulses delayed more than 2-4 seconds to activate an alarm ,when a pulse re-establish that the alarm goes out, of course for 4-6  independent sources of pulses
Project need to monitor mixing granulated food with 4-6 components
Logged
zuisti
Senior Member
****
Offline Offline

Posts: 371

Thank You
-Given: 219
-Receive: 567


« Reply #6 on: December 11, 2008, 09:02:50 21:02 »

Hi;
I agree with Itp,
Simply use a "Dual retriggerable monostable multivibrator" type 74hc123 to sense two pulse (use two same ICs for 4 pulses and so on ... )

 Study the datasheet here:
http://www.nxp.com/acrobat_download/datasheets/74HC_HCT123_4.pdf

I think  it's possible to realize the circuit without any processor... it's a really "older" solution.
Good luck
zuisti
Logged
Parmin
Hero Member
*****
Offline Offline

Posts: 544

Thank You
-Given: 357
-Receive: 126


Very Wise (and grouchy) Old Man


« Reply #7 on: December 11, 2008, 11:27:19 23:27 »

Agree with ITP and zuisti

Definitely doable..
Logged

If I have said something that offends you, please let me know, so I can say it again later.
hogar
Newbie
*
Offline Offline

Posts: 28

Thank You
-Given: 7
-Receive: 13


« Reply #8 on: December 11, 2008, 11:39:12 23:39 »

Thank you guys for advice!!!
Logged
titi
Active Member
***
Offline Offline

Posts: 192

Thank You
-Given: 1435
-Receive: 705



« Reply #9 on: December 12, 2008, 10:14:30 10:14 »

Hi,

This is an example with NE555 found in the good soft : 555 Etcetera,
 posted on sonsivri : http://www.sonsivri.com/forum/index.php?topic=5468.0

To calculate the value of R1 and C1 use the same soft.

Regards.
« Last Edit: December 12, 2008, 10:17:32 10:17 by titi » Logged
Pages: [1]
Print
Jump to:  


DISCLAIMER
WE DONT HOST ANY ILLEGAL FILES ON THE SERVER
USE CONTACT US TO REPORT ILLEGAL FILES
ADMINISTRATORS CANNOT BE HELD RESPONSIBLE FOR USERS POSTS AND LINKS

... Copyright 2003-2999 Sonsivri.to ...
Powered by SMF 1.1.18 | SMF © 2006-2009, Simple Machines LLC | HarzeM Dilber MC