Lock-start-puter circuit.

KyleYankan · 07-13-2005, 09:52 PM

Hi everyone. I have a quick question. I'm trying to devise a circuit that works off my car locks. Basically they get a negative pulse, which starts a latched relay, which will power up the ACC line going to the startup/shutdown controller. I've included a picture of my current circuit but I've noticed one problem. In order to stop the chained relay (stuck-on) action you need to kill the 12volts going to it. So, I have it rigged to pin1 of the parallel por,t though a molex conntor would work two. Here's the issue: The moment the PC turns on the ACC line turns back off. This in turn tells the controller to shut down. Hmmph. I was wondering if I throw it on pin 2 or 3, and have a program that waits oh ... 2 minutes, then turns ON the pin, if it'll work. Only problem is that start-up sequence tends to be a bit of a pain, and flashes the pins. Any ideas?

BTW, part of the schematic is form the12volt.com

Curiosity · 07-13-2005, 10:25 PM

Many of us do something like this, but with the ACC turning it on. If your door unlock is long enough to get the PC to output 12V, it will hold the relay closed until it shuts off. Just make sure the diodes are in the right direction and it will be safe. They can be small 1/2 amp generic ones.

KyleYankan · 07-13-2005, 10:43 PM

That makes sense, but I just redesigned the circuit while I walked the dog. BTW: What relays are you using? You have two relays hooked up in series there, and it seems to me 12v wouldnt do it. Unless there 5v relays?

Anyways, what I did is this:

Replace the bottom relay/parallel port bit with a relay that has a N.C. position. When it's N.C. the rest of the circuit gets 12V. Have the relay hooked to the ACC line, so when the ACC goes on, the circuit loses 12V. Have the circuit's output and the ACC line hooked together with a few diodes. Voila.

KyleYankan · 07-13-2005, 10:45 PM

Oh, BTW, about the locks being long enough. I'm just adding electric locks now. It's a set of 4, and I only have two doors I can hook it up to in my minivan. Can't run a wire into the 3rd door. So I have plenty of extra places to plug into. Additonally, I have 2 extra push/pull solenoids. If I don't find something for them soon, I'm gonna sell them off here.

Wiredwrx · 07-14-2005, 12:19 AM

I am trying to understand your original schematic. Can you please clarify what the things in the blue square, and explain what the stuff in the red square does, in particular, connecting the - output of the computer parralel port with the postive going into the relay in the red box?

Michael

Curiosity · 07-14-2005, 12:22 AM

I've never really used automotive relays, so I might be wrong on that. I think the negative pulse on the unlock just connects to gnd, so for the positive you would connect the relay coil to constant 12v and the door unlock wire would ground it and close that relay. The contacts would connect to 12v and output to that fist diode. I think all that's right. The second relay doesn't look right though. The coil should be connected to gnd and 3 different inputs (with diodes on each one): The pulse from the 1st relay, output from the PC, and ACC. The contacts should connect to constant 12v and to the PSU. This way the unlock or ACC going on would turn on the PC and the PC will hold it on. The parallel port could connect to ACC. If you're writing your own software, you can just ignore if the ACC is low when it first starts and wait a couple minutes before assuming the key just never will be turned on.

KyleYankan · 07-14-2005, 12:26 AM

michael - sorry about that. I messed up that part of the schematic. The aprallel port should be powering the relay. Rotate it 90 degrees :-D

The Fused 12v+ is the 12v from the battery. The "Constant 12v" is the output of the circuit. When it receives a pulse from the locks, it then turns it itno an constant 12v. That would go into the ACC line with diodes. I'm working on my newer version now, so you all can see it.

KyleYankan · 07-14-2005, 12:48 AM

Here's the new schematic with COLORS

BTW: I threw colors i nthere to make it easier to ask questions about a certain relay/part.

Curiosity · 07-14-2005, 12:52 AM

Ohhhh! What shutdown controller are you using and where does this connect to it?

SickVette · 07-14-2005, 11:27 PM

Kyle...off subject. How come you can not install a door lock actuator in your sliding door?

KyleYankan · 07-14-2005, 11:31 PM

sickvette: my sliding door has nowhere to run the wires. There's no wire loom going into the doors, and no obvius way to put it in there. the only way I can htink of is if there was a way to control the lock from intside the chassis. I don't care about the abck door that much though.

SickVette · 07-14-2005, 11:34 PM

Well if you ever do decide that you want to install one you can get a contact plate to solve that problem. They are easy to install. One piece mounts on the door and the other on the door jamb...the two connect when the door is closed. I have installed dozens of them and they work great. Just thought you would like to know.

KyleYankan · 07-14-2005, 11:40 PM

awesome! do oyu know of a place to get them at?

Wiredwrx · 07-15-2005, 01:05 AM

Quote: Originally Posted by KyleYankan

Here's the new schematic with COLORS

BTW: I threw colors i nthere to make it easier to ask questions about a certain relay/part.

I don't think your schematic will work because there is no postive for the Blue relay coil.

Try this. Sorry for the crude schematic, but you should be able to understand it. Basically, the black lines are the contacts of the relay, oriented just as the contacts on an actualy automotive relay is.

Michael

KyleYankan · 07-16-2005, 11:31 PM

blah - blue relay is N.C.