pulsed to timed

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=30414
Printed Date: May 08, 2025 at 1:57 AM

Topic: pulsed to timed

Posted By: robbie2883
Subject: pulsed to timed
Date Posted: April 15, 2004 at 10:53 AM

i have been racking my brain trying to figure out how to take a 1 second pulse and turn it into a timed output for a bosch relay. i know they make timed relays, but all the ones I find are like 50 and 75 bucks. I don't feel like spending that much. i'd like to just make it using some caps and resistors if possble. Thanks for any help.

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if its jammed force it - if it breaks in the process it needed to be fixed anyway
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Replies:

Posted By: xetmes
Date Posted: April 15, 2004 at 11:07 AM

what do you want it to do?

After a pulse stay on fo a certain period of time?

Posted By: robbie2883
Date Posted: April 15, 2004 at 3:15 PM

yeah...about 10 seconds or so

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if its jammed force it - if it breaks in the process it needed to be fixed anyway
posted_image

Posted By: markcars
Date Posted: April 15, 2004 at 4:15 PM

Use a 555 timer. One of the most versatile timers I have ever used. Options are almost limitless.

Posted By: robbie2883
Date Posted: April 15, 2004 at 10:35 PM

i've heard about these. they have them at radio shack right? can you give me any info on how to wire it up? it's an intigrated circuit right?

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if its jammed force it - if it breaks in the process it needed to be fixed anyway
posted_image

Posted By: xetmes
Date Posted: April 16, 2004 at 6:25 AM

its a small IC that can be used in a monostable set-up. here is a circuit and timing calculator. You may want to add a transistor to the output to drive a realy.... They can operate at 12V as well, no need to drop the voltage down.

Posted By: robbie2883
Date Posted: April 16, 2004 at 6:51 AM

thanks man....that will work. one thing though.....will the output be + or -?

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if its jammed force it - if it breaks in the process it needed to be fixed anyway
posted_image

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