"Delaying" a 12 volt signal?

**kiltjim** · 10-19-2004, 01:05 AM

It may be late, I may be a little fried from exams and the such, but I'm usually pretty quick on figuring out this kinda stuff.

I need to "delay" a 12 volt signal getting to one part of a project I'm working on. Something like this....

Switched +12v ----> Delay of sorts ----> Delayed Switched +12v

I basically need to prevent a relay from turning on too quickly.
(A huge length of wire won't work...so don't suggest it...)

Any suggestions?

**rando** · 10-19-2004, 01:08 AM

You can use an RC network to implement a delay. Search the forums for examples.

**kiltjim** · 10-19-2004, 01:14 AM

Just found it. See? Too much work, and not enough sleep hurts.

Unless you're a programmer. But that was last semester.

**Nic** · 10-19-2004, 01:34 AM

(A huge length of wire won't work...so don't suggest it...) <<< hahahaha

**megamind** · 10-19-2004, 01:46 AM

We use special delay relais. You have them in 2 versions:
1: Give em power, they wait a period of time and switch in
2: Unpower them and they wait a period of time to switch off

You need the 1st one, ill look for you if i can find it somewhere.

In the meanwhile here's a scheme:

Its for 230v ill make a 12v version with a capacitator and a relais if you want to

edit: you should look at the topic sticky in the forum

http://www.mp3car.com/vbulletin/atta...tid=4455&stc=1

**mushin** · 10-19-2004, 01:56 AM

I'm no expert on these things, but wouldn't using a 555 timer be easier?

**kiltjim** · 10-19-2004, 02:02 AM

No, the RC network is what I was looking for. Now, all I have to do is find a resistor that is low enough not drop the voltage too far. And match a capacitor to it.

The 555 timer would work in one shot mode, but not for the size I'm working with.

**Multiplayer** · 10-19-2004, 02:16 AM

Kiltjim
If you look in the sticky "scematics" theres som nice delay circuits, which are rather simple circuit's.

**djScript** · 10-19-2004, 09:46 AM

If you need an easy way, just get the PAC TR-7 universal trigger module from your local car audio shop. It's also known as "Alpine Video Bypass" module on ebay.

**XxAndyxX** · 10-19-2004, 10:17 AM

Here's what you need to do; I just did this in my car yesterday. You need to buy a DEI pulse timer relay. The part number is 528T. Basically what it does is when it receives a signal (can be + or -) it will disconnect a wire for a set amount of time (you can adjust it from 0 to 90 seconds). Which sounds like what you are wanting to do. Here is a link for the part http://www.drdetailshop.com/528T.htm

I saw them on ebay going for like 6 bucks and I got my from a local shop for $10.50. So I don't think you should buy it from the link above.

I didn't read the replys so if this is redundent I apologize.