555 Timing delay

[ericgibbs]

So what makes the delayed 555 output pulse different than the alarm output pulse? The alarm output pulse can activate the starter relay just fine.

Could you please be any chance update the diagram for me?

And is my circuit broken now? Since it won't output anymore on 12v, even though it seems to work perfect with 5v?

The delayed output doesn't have the current drive capability of the initial alarm pulse.
The starter relay requires far more current than a 555 can deliver.

A revised diagram has been posted.

Its possible that you have blown the 2nd 555.

 

[jelle2503]

Hi Eric, thanks for the swift replies.

That scheme is something to break my leg over. Something I'll be having fun with.

I see now you want to use a relay to be able to activate my starter relay. I'll let you know if it works.

PS I just figured that the 555 output pulse would have enough current to close the relay. Excuse my noobness

 

[jelle2503]

So had another go. Mosfet was not in stock so took a while. Your current set up works great.

https://imageshack.us/photo/my-images/64/20110704174955.jpg/
^ Stupid imageshack rotating my image for no reason!

Anyway I'll produce this into a final board, to hope it still works. Then I'll build it on my bike. Then finally delayed remote starting.

 

[ericgibbs]

hi,
The breadboard layout looks OK on that image.
Lets know how the final build goes.

 

[jelle2503]

**broken link removed**

So here's the final build I just tested it and it works. Phew.

Had some trouble first time around, but knowing this I prepped this little piece of board to save me a lot of time

Thanks man. Will probably mount this in my wiring soon. As soon as I waterproof the board (any tips?)

BTW is it OK to have the board directly to my battery? IE. it won't use a lot of current?

 

[ericgibbs]

hi,
The current drain is quite small when the relay is not energised, I would always connect a project to a car battery via a fuse, say a 2A fuse, in the +V line.

Fuse in series with the D2 diode, close to the battery end of the +V wire.