Time delay

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=80277
Printed Date: June 30, 2025 at 2:32 PM

Topic: Time delay

Posted By: b1mmuo27
Subject: Time delay
Date Posted: July 13, 2006 at 10:48 PM

Does anyone or has anyone built a time delay circuit. I am trying to delay the lock pulse 5 seconds from the initial lock pulse.(12VDC) Thanks posted_image

Replies:

Posted By: b1mmuo27
Date Posted: July 14, 2006 at 5:42 PM

BTW-I did read the forums & didn't see any the were timed on delay. posted_image

Posted By: b1mmuo27
Date Posted: July 14, 2006 at 6:06 PM

They do the opposite of what I want. They time delay off. I want time delay on.

Posted By: dualsport
Date Posted: July 14, 2006 at 8:30 PM

You could make a DIY circuit with the following parts- should be less than a dollar in parts if you don't count the relay.

2     C1,C2     4.7uF
2     D1,D2     1N4001
1     K1     RELAY SPDT
1     Q1     BS170
1     R1     1M
1     R2     100k
1     U1     CD4001
1     U2     40106

You'd be better off with a canned commercial product if you haven't built any circuits before, if you're planning to control a door lock with it. Wouldn't want it to get stuck on-
But, if you want to try, let me know and I'll sketch it out.

Posted By: dualsport
Date Posted: July 14, 2006 at 10:45 PM

Power and ground inputs for the two ICs not shown;
(Pin 14: 12V)
(Pin 7 : Ground)

You can try this as a start- tweak the resistor and cap values to get the timing you want; you should be able to change the delay time and the pulse output time with the two RC combinations.
Logic parts are available from mouser.com; make sure you get the PDIP package size unless you're used to working with the tiny stuff.