Thread: Accessory Line Delay circuit - Any ideas?

Originally Posted by MiniRX7

I want to use a relay to switch the invertor on and off. HOwever on my car, when you turn the car to the crank position, it kills the 12 VOLT accessory line output.

You can use this method.
Car ACC wire --> Diode --> relay switch to inverter.
Car IGN wire --> Diode --> join with the relay wire above.

The reason is when the key at crank position, the ACC wire is cut off but the IGN wire is still hot so the relay wire get power from there. The diodes are there to stop power from mixing up your car electrical system.
That is how I wire the relay that turn on the Inverter in my car.

Interesting ideas.

To the first idea with batteries, i was trying to avoid using any batteries in the circuit.

To the 2nd idea. Its a nice idea but i think there may be a delay between the switch over from ACC to IGNITION lines..and that may cause the relay to unlatch.

Is there any type of capacitor that can codl the 12 volts for about 5 seconds at a minimum?

Like running a diode to teh cap and cap to the relay swith? is that enough to keep the relay on?

ED

The ACC line always has power except when the key is in the CRANK position.
I don't think the ACC line is cut off during the switch from ACC to IGN. To find out, does your radio turn off while switch from ACC to IGN? Because most radio is turn on when the key is in ACC pos.
The IGN always has power when the key is in IGN, during and while in START/CRANK pos.

Originally Posted by MiniRX7

To the 2nd idea. Its a nice idea but i think there may be a delay between the switch over from ACC to IGNITION lines..and that may cause the relay to unlatch.

Thy should overlap....

POS1 ACC
POS2 ACC & IGN
POS3 IGN & CRANK

Acc is live in pos1 & pos2
Ign is live in pos2 and during cranking, so a feed from both will cover all positions.

Matrix, what sort of diode do you need for this?

Originally Posted by Laidback

Matrix, what sort of diode do you need for this?

I don't remember what it is (IN5819 or IN4004) but it a small one. A relay doesn't draw that much current that is why I use a small one. But bigger is always better (IN5822).

Actually your right, the ignition is always live...

But will the momentary switch over from accessory to ignition kill the invertor?

Its the crank position that i am worried about, because the crank position is when the accessory gets killed meaning bye bye x-box and invertor.

So my real question is, i connect the diode to the accessory line and the ingition line.. Feed both to the trigger on the real, and one or the other will continually feed the invertor? Hmmm sounds like it will most definitely work for sure. ONce i turn the key to POS 2, ignition takes over, and in crank it will continually give ignition. and as the car is running, the ignition will stay on keeping the relay alive and switch back over to accessory..

WOW.. thats the best idea, and I most definitely think it will work.. And that even solves my other problem. I am connecting my xbox power switch to my remote starter alarm. So that i can turn the xbox on for wireless FTP transfers remotely. As teh car starts, then the invertor is on since ignition is power.. Then i hit the channel three to pulse the X-BOX power switch and voila.. all is turned on..

Awesome.

I don't know if this is true for all cars but on my 2001 Celica

Key in:

Off = No radio
ACC = Radio switches on
Ign = Radio continues to play with no interruption
Crank = Radio switches off and then back on when key release back to Ign.

Does that match up with earlier??? I think it does as it implies the headunit is connected only to ACC live feed and hence due to overlap continues to play when I move the key to IGN. It then cuts off when cranked.

This also explains when I remote start the engine or have it idling with the key out why my headunit doesn't come on. The Clifford installers were supposed to tie BOTH into the remote start system and obviously have only done the IGN line.

Originally Posted by NJay

I don't know if this is true for all cars but on my 2001 Celica

Key in:

Off = No radio
ACC = Radio switches on
Ign = Radio continues to play with no interruption
Crank = Radio switches off and then back on when key release back to Ign.

- All Toyota Cars Ignition key switch work the same (at least here in the states). Your Celica's switch work exactly like all Toyota over here.

Does that match up with earlier??? I think it does as it implies the headunit is connected only to ACC live feed and hence due to overlap continues to play when I move the key to IGN. It then cuts off when cranked.

- HU is connect to the ACC line that is why during crank, the radio shut off.

This also explains when I remote start the engine or have it idling with the key out why my headunit doesn't come on. The Clifford installers were supposed to tie BOTH into the remote start system and obviously have only done the IGN line.

On Viper Remote start system (one I install in the Supra), there are wires for Starter, ACC, and 2 IGN. The installer must of be lazy not to connect the ACC line to your car ACC or the Remote start system doesn't have the ACC line.

Originally Posted by MiniRX7

WOW.. thats the best idea, and I most definitely think it will work.. And that even solves my other problem. I am connecting my xbox power switch to my remote starter alarm. So that i can turn the xbox on for wireless FTP transfers remotely. As teh car starts, then the invertor is on since ignition is power.. Then i hit the channel three to pulse the X-BOX power switch and voila.. all is turned on..

When I need to do config the carpc or transfer short file or anything can be done in 15 min. I just remote start the car -> start the carPC and VNC on my desktop to the car PC. After I finish the task, shutdown the PC via VNC and a minute later, shutdown the car via alarm remote. I don't have to see or walk to the car for the whole process.