admin i need a diagram

I am pretty sure it was here where I saw it.  It made a brief pulse when 12 volts was applied and retained.  When that voltage was released, it made another brief pulse.  So it basically took a steady 12 volts and converted it to a pulse and then another pulse when the voltage was released.   I have searched the site several times, maybe it was somewhere else.  Thanks in advance.

-------------
Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

I vaguely recall creating something like that. I'll try to search for it when I get in.

-------------
the12volt • Support the12volt.com

Don't hurt yourself, Ihave it figured out, but it is going to take 3 relays.  But if you can find it, I am sure he would be better off with a single relay.   Thanks

-------------
Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

I know I didn't do it with a single SPDT relay. Three sounds reasonable.

-------------
the12volt • Support the12volt.com

Thanks for looking.  If I stumble across it somewhere I will get it to you in case you ever need such an animal.

I did stumble across this very useful page of relay information.  https://www.dlcparts.com/images/BoschGuide.pdf

-------------
Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

I think I have it down to 2 relays.  Wiring the first relay so it has positive output when energized, and ground out when not energized.  This will feed into the following relay setup, when the first relay turns off and applies ground to the switched 12v terminal, the cap is charged and should pulse the relay again.  The diode will have to go.  As far as I can tell it is there for backlash prevention only.

-------------
Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

I don't know if you want to use any solid state parts or not, but this post describes something like what you might be looking for.
Uses one relay, but the key is really the XOR logic gate.
I can't picture a way to do it with only a single relay and passive components.

I guess a link might help.

https://www.the12volt.com/installbay/forum_posts.asp~TID~96613~PN~1

You were right, the link helped a lot.   That may be what I saw, I know what ever it was, it was here.  The wording appears as though it may have been what I saw.  Thanks for that.  Do you think my last posted idea will work?   I think he will go for 2 relays.

-------------
Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

You know, there's a totally simple way to do what you're looking to do- if you simply connect the relay to a single cap and nothing else.
When you first apply 12V, the relay clicks on, and once the cap charges up, the relay turns off.

Now there's 12V on the cap, so when you shut the ignition off again, there's 12V across the coil again, but in reverse polarity. Once the cap discharges, the relay turns off.
The only requirement is that the input is switching between 12V and ground, not 12V and open circuit, because it has to pull the current backwards when you shut down. If it's a normal ignition circuit, it should have no problem doing it.

If you need to adjust the output pulse duration, just use different size caps or different relays. The lower power relays will give you a longer duration without having to stick an uber cap in there.

If you need it to operate with an open circuit/12V input, then solid state stuff would be needed, because it needs a hard ground for the opening pulse.

I am pretty sure it will work, And I need to check the device, it may return to a ground state instead of open.  That would be nice.  If not we will have to use 2 relays.  

Oh well thanks for the help, but it seems as though it may have all been for nothing.  I seem to have become invisible in the topic that I thought I was going to be of help in.    Thanks again.

-------------
Let's Go Brandon Brown. Congratulations on your first Xfinity Series Win. LGBFJB

Invisible? Where? Certainly not here-

Yeah, who would've thunk it?