need a relay to hold 12 volts up 30 sec

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=113707
Printed Date: May 13, 2025 at 10:12 PM

Topic: need a relay to hold 12 volts up 30 sec

Posted By: mys2
Subject: need a relay to hold 12 volts up 30 sec
Date Posted: May 09, 2009 at 1:23 PM

Hi all,

i need a relay the will hold 12 volts up to 30 sec + when starting the viehicle. I know you can just use the ignition wire in the viehicle. What i am trying to do is take a acc. wire and make it like a ignition wire. So when i start the viehicle the voltage does not drop to 0 volts and stay around 12 volts + on thI acc. wire. Then when I shut off the viehicle the wire will rest a ground as it should.

Thanks.

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funny

Replies:

Posted By: KPierson
Date Posted: May 09, 2009 at 7:06 PM

a PAC TR-7 should do that.

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Kevin Pierson

Posted By: i am an idiot
Date Posted: May 09, 2009 at 7:11 PM

Part Number: TR7

The TR7 Is a universal module that combines many features into one box. Carrying one TR7 will cover more than 16 different SKU#.

• Low voltage trigger.
• Alpine video bypass.
• Latching outputs.
• Double pulse output.
• Pulse extender.
• Horn honking output.
• Linear actuator controller.
• Door lock pulse generator.
• Channel splitter.
• Pulses to constant output.
• 3 in 1 timer outputs.
• Pulses to latch/unlatch outputs.
• Pulses to pulse output.
• Pulses to timed output.
• Latching outputs #2.
• Turn on pop delay.
• Delayed amp turn off.
•(PLUS 2 more) in a new case design.

This product is solely for the purpose of interfacing with a rear backup camera. PAC warrants that the product delivered pursuant to this Invoice shall be free of defects in material and workmanship. PAC SHALL NOT BE LIABLE FOR CLAIMS OF ANY LOSS OR DAMAGE, CONSEQUENTIAL, DIRECT OR INDIRECT, ARISING FROM THE SALE OR USE OF PAC's PRODUCTS. CUSTOMER IS SOLELY RESPONSIBLE FOR COMPLYING WITH ALL FEDERAL, STATE AND LOCAL LAWS PERTAINING TO THE USE OF THE PRODUCTS.

Posted By: dualsport
Date Posted: May 09, 2009 at 7:51 PM

Seems a bit of overkill for such a simple function though.
Wouldn't a diode, capacitor, resistor and transistor do it easily enough?

Posted By: hotwaterwizard
Date Posted: May 14, 2009 at 12:44 AM

Check out this Circuit !!

https://ourworld.compuserve.com/homepages/Bill_Bowden/page2.htm#relay_i.gif

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

Posted By: dualsport
Date Posted: May 14, 2009 at 8:49 AM

Exactly! I'd use the second version to ground switch the relay-