93Views6Replies

Author Options:

Automotive Power Loss Annunciator Answered

The photo shows what I'm dealing with: a sound module ($2.50 including shipping from China) and an automotive auxiliary power cord (cigarette lighter.)

The sound module has a "play" button at the end of the yellow wires.

The "black box" has two tasks:

                - detect loss of power on the 12V cord
                - momentarily connect the two yellow wires (as if the button switch had been pressed.)

So far I’ve been told that some sort of relay and a timer could be involved, but since I’m not a Electrical Engineer, I don’t know the specifics. I know that in the automotive world, there are big, bulky relays, but I'm wondering if there are relays in the integrated circuit world?

I really need specifics like part numbers and circuit diagrams. Thanking you in advance for your help.

Comments

The forums are retiring in 2021 and are now closed for new topics and comments.
0
crapflinger
crapflinger

6 years ago

do your dome lights turn on when you turn the ignition off? if not, do they turn on when you open the door? if either of those are true, you could tie a relay into that circuit that would close the "play button"

0
willy41
willy41

Reply 6 years ago

Now that's the best suggestion yet! I like the KISS principle. In the meantime, I hope you can find some heavier toilet paper.

0
caitlinsdad
caitlinsdad

6 years ago

Maybe you should have spent the $2.50 into a plug in cigarette lighter automotive voltage tester/status indicator with LEDs. I'm guessing you want to know if the battery is good or if the alternator is charging and if the battery is charging.

0
willy41
willy41

Reply 6 years ago

Those are good guesses Dad, but I really want the anunciator to remind me to do something when I shut off the engine. Being recordable, it will allow me to change the reminder message at will.

At this point, I'm dreaming of a relay that is open at 12V or 0V, but would close momentarily when the power fell through 6V. That would make things really simple.

Thanks for considering my query.

0
steveastrouk
steveastrouk

Reply 6 years ago

What you NEED then is a "Window comparator", which needs a chip to build one. Are you up to that ?

0
willy41
willy41

Reply 6 years ago

Thanks for considering this, Steve, but I was hoping for a simple off the shelf solution. I don't have the background to build something using a chip.