Delay for momentary circuit

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=38794
Printed Date: May 21, 2024 at 1:26 PM

Topic: Delay for momentary circuit

Posted By: bulgogi777
Subject: Delay for momentary circuit
Date Posted: September 08, 2004 at 11:23 AM

Hi everyone, I'm hoping I can elicit some EE help :)

I'm planning on using the Constant to Momentary circuit listed on this site to fire up a computer I have hooked to my switched 12v source. This would work perfect as is, but through much frustration I figured out that my inverter needs about a second or two to warm up before outputting.

So I'm using this design right now...

posted_image

with the momentary 12v output leading to a relay that shorts my "On" button for my computer.

So my question is this: what would I need to do to delay that momentary output from happening for 1-2 seconds?

Replies:

Posted By: hotwaterwizard
Date Posted: September 08, 2004 at 11:20 PM

Here is a Circuit that will do the Trick. posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: bulgogi777
Date Posted: September 09, 2004 at 8:44 AM

Awesome! I'll give it a whirl... by the way, do you know which values I have to change in order to change the delay timing?

Posted By: bulgogi777
Date Posted: September 09, 2004 at 11:47 AM

actually, do you know where I can get a MPSU-10? I've been having trouble locating one or an equivalent.

Posted By: hotwaterwizard
Date Posted: September 09, 2004 at 6:25 PM

ECG191 Now Obsolete

2N6558

SK3232

BF859a

MJE340 if 100ma or less

The Original is 500ma 300v

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: hotwaterwizard
Date Posted: September 09, 2004 at 6:37 PM

Here are some more! I have many.

posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: bulgogi777
Date Posted: September 10, 2004 at 9:36 AM

cool, I think I'll use the 555 monostable circuit 'cause I'll be able to get all the parts from the ratshack :)

but real quick, I'm assuming that that diode is a standard 1N4001 & that round thing is the "motor"(ie, what I'm supplying power to)?

Posted By: bulgogi777
Date Posted: September 10, 2004 at 9:42 AM

oh, and would I be able to use a .01uF cap instead of that 10nF one?

Posted By: bulgogi777
Date Posted: September 10, 2004 at 9:48 AM

sorry, I forgot to ask before, what's the difference in the letter prefix of the timer chip?

radioshack has the TLC555 and the LM555, are these ok instead of the UA555?

I'd prefer to buy locally just cause its a little quicker, thanx!

Posted By: hotwaterwizard
Date Posted: September 10, 2004 at 6:04 PM

micro 10-6 0.000 001
nano- 10-9 0.000 000 001
pico- 10-12 0.000 000 000 001
.01 microfarads x 1000 = 10 nanofarads
10 nanofarads x 1000 = 10,000 picoFarads
so your answer is the Capacitor .01 is 1000 times too big.

The Timer IC is the same IC but Different Manufactures have their own Prefix at the beginning.

And the Diode 1n4001 or 1n4002 0r 1n916 it really doesn't matter which one it just protects the IC from spikes.

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: hotwaterwizard
Date Posted: September 10, 2004 at 6:34 PM

here is another one

you could hook this circuit to a Latching relay circuit.

+ posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: hotwaterwizard
Date Posted: September 10, 2004 at 6:35 PM

Here is the other circuit. posted_image

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: hotwaterwizard
Date Posted: September 10, 2004 at 6:39 PM

Here is another site that may help.

https://ourworld.compuserve.com/homepages/Bill_Bowden/555.htm

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John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !