Momentary Output Pulse

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=140844
Printed Date: April 28, 2024 at 7:17 PM

Topic: Momentary Output Pulse

Posted By: pts760
Subject: Momentary Output Pulse
Date Posted: February 13, 2016 at 12:18 AM

Using this diagram: posted_image

How would I extend the pulse to 5 seconds instead of 1/2 second? Multiply the capacitance of the polarized cap by 10 which would equal 10k uF?

I searched the internet for 2 hours and couldnt find a simple circuit to do what I want so I was hoping someone here could help me out. Thanks in advance.

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I drink current, eat ohms, and bleed voltage

Replies:

Posted By: kreg357
Date Posted: February 13, 2016 at 9:33 AM

While a bit more expensive, would a Directed 528T be an alternative? It's adjustable from 1 - 90 seconds and 15 Amp capable. A nice package and easily adjustable timed output.

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Soldering is fun!

Posted By: pts760
Date Posted: February 13, 2016 at 10:03 AM

I've used a 528t before and it would work but I would like to add some more knowledge to my bag of tricks by using a relay, cap, & resistor and understanding how that circuit works.

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I drink current, eat ohms, and bleed voltage

Posted By: pts760
Date Posted: February 14, 2016 at 4:37 PM

This diagram gets posted on his website and no one knows how the cap/resistor values are calculated and how that relates to delay in seconds?

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I drink current, eat ohms, and bleed voltage

Posted By: Ween
Date Posted: February 14, 2016 at 7:11 PM

Read here for more info: https://www.electronics-tutorials.ws/rc/rc_2.html
The delay will depend upon the coil resistance, drop out voltage of relay, capacitance value, parallel resistor value.

Posted By: pts760
Date Posted: February 14, 2016 at 7:51 PM

Excellent! Thank you for the info and direction. I really appreciate it.

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I drink current, eat ohms, and bleed voltage

Posted By: geepherder
Date Posted: February 16, 2016 at 12:44 PM

For a few seconds:

https://www.diymobileaudio.com/forum/how-articles-provided-our-members/2727-designing-your-own-delay-circuit.html

For a few minutes:

https://www.youtube.com/watch?v=GeveeSTyvGs

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My ex once told me I have a perfect face for radio.

Posted By: luhanz.18192
Date Posted: June 15, 2016 at 12:56 AM

This is my first post on this forum so please bear with me. Im using a bluetooth speaker as a transmitter and a power amp to eliminate the radio in a older car and what im wondering is how i would use a constant power sorce (ignition switch on) to send a single pulse to the speaker toeeliminate a tactile switch. I already have a DC/DC Converter 12v Step Down to 3V/3A Power Supply to send the proper voltage just not sure about the constant to momentary. Any help would be greatly appreciated.

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Luhanz