car radio timer

[iceze]

Hi guys

I've changed my car radio headunit to a android one, and lost a feature that was on the factory unit.

Normally after switching off the car, the radio will stay on for about 5mins (not too long that it drains the battery) or until the drivers door is opened and switches off at this point.

The current radio switches off immediately when the ignition is switched off.

As the unit doesn't do this, I want to design something that can replicate this.

For the timer part, could I use a timer relay like this (aliexpress 4000918306923)? but this only has a 10sec timer and I'd ideally want something . I guess I would have the ignition as vcc and always live on nc/no part?

How do I incorporate the door switch so if its on timer, it'll immediately switch off? I don't want it to switch off using the door if ignition is on.

Or is there a better/ combination circuit I need?

 

[danadakk]

Google "car delayed turn off headlights", many circuits for turning off stuff.


Regards, Dana.

 

[BradtheRad]

Ignition wire goes dead when you turn off the engine. Therefore you must reroute your radio so its power comes from a wire that's always live (example, headlights). Your project shall use Ignition wire as a logic input. The door switch is a second logic input

Where is your fusebox? In olden days it was under the dashboard. Or else if it's near the engine, find an opening so you can run a wire to it.

Does the door switch control your dome light? You might be able to locate a wire in the dash which goes to these.

 

[iceze]

Thanks Dana, but I couldn't find anything that does exactly as required.

Thanks BradtheRad, I am indeed looking to make a circuit like this, as I can't find anything like this.

I should be able to find all the wiring. I.e permanent live, ignition and door switch(courtesy light usually comes on for any door. I want to wire so only the driver door is used) .

I was thinking of using a timer relay like posted on my original post from aliexpress but am not sure how to add the driver door sensor to interrupt and immediately shut off the radio only when the timer is running.

 

[BradtheRad]

My car (2006 model) does what you want. It maintains power to the stereo and windows after I switch off the engine (for ten minutes or when I open the door). I have not seen any door switch and I wouldn't know where to clip the wire. I suppose the fuse box contains the wire which powers the accessories.
I think the delay is not in the radio but in the computer where software performs the logic.

Decades ago I built a timer for our dome light (after we left it on a few times draining the car battery). I was just lucky I could get at the wire behind the dash. I clipped it and spliced in my circuit (based on a 555 IC and relay). I got it to work okay, but if I switched off the light momentarily, my circuit was defeated because the cap had a charge already and a second delay failed to begin.

Normally it shut off the dome light after 3 minutes. However by adding a few more components you can get 10 minutes delay from a 555.

You may need to install your own door sensor. A reed switch can do the job. Attach a magnet to the door. Install your switch on the car body.

 

[vfone]

There is a difference between American cars and European cars when shut down the engine.
On American cars you can still use some of the electrics when the engine is stopped, but in most European cars everything is shut down, including the headlights. There is a possibility to turn on the electrics (and lights) without starting the engine, but you have to do manually. This is an advantage because you will never forget the lights on, to drain your battery.

 

[dr pepper]

Do the electric windows work on your vehicle for a period of time after you sitch off, a lot do these days, if so see if you can download a schematic and take a fuse tapping to power the radio, if its a high power radio then use a relay.