push button switch to lock / unlock doors

I currently use 2 switches, each with a feed from the negative on the battery to control the lock and unlocking of my doors,  I asked the alarm guy to show which wires to connect to, but he couldn't tell me how to do it with only 1 switch

Is there a way of using 1 push to make non latching switch that when pressed once will lock the doors and when pressed again will inlock the doors, this doesn't need any connection to the alarm as i just want a button on the dashboard that locks and unlocks the doors

Cheers for any help received, schematics and real simple explanations would be greatly appreciated

Daz (UK)

p.s. I have  a '95 peugeot 306

thanx for the reply but not really m8,

i already had the idea of the rocker, but it is fundamentally the same as i already have,  2 switches just combined into 1 housing

The single switch idea I saw it  in my mates car (citroen c3) and its well smart and would really like the same function in mine, just 1 switch, push to make which handles the locking and unlocking alternately.

was reading another thread which mentioned a set / reset logic circuit, not sure if this is what i need, also checked out relay apps and that nearly looked promising but required 2 wires (lock, unlock) from the unspecified switch, which i presumed must have been a rocker switch.

this circuit doesn't have to be connected in any way to the alarm just a simple swtich closing the door type circuit

cheers but the search continues

daz

You'll need to add a latching relay  http://www.hosfelt.com/en-us/dept_111.html  (near bottom of page)  to work with the type of switch you want to use to lock and unlock your doors. Each time you press the switch it will alternately send a ground (or positive pulse, whichever you need) to the existing lock and unlock relay. 

the12volt • Support the12volt.com

when you say "add" would this be to other relays, or is this the only relay i use?

the switches i use currently feed into the central locking "brain" and that handles the rest of the operation, my circuit, if you could call it that is nothing more comlicated than a piece of wire from the negative terminal on the battery going to 2 swtiches that continue to 2 wires my alarm guy pointed out control the locking and unlocking, located under the carpet by the drivers door, i don't use relays at the moment so was wondering is this the only one i need

with it being a latched relay, when i press the button once will the relay keep it active (for want of more technically accurate word) so the central locking sees it as the button being continuosly pressed

if you have any diagrams that could better explain this i would be extremely grateful

regards

daz

Yes, you will have to add this to alternately send a pulse to the lock and unlock relays. The "locking brain" contains these relays. The two wires your alarm guy pointed out to you are the leads going to the coils of the lock and unlock relays. The output of the switch through the latching relay will supply a pulse for each alternately with each press of the switch.

When the coil of the latching relay is energized and released, two contacts have continuity ( the common and one other terminal, call it "A"), when the coil is energized and released again two contacts will have continuity ( the common and a different terminal, call it "B" ) . If you use the output of the switch to energize the coil of the latching relay and also connect it to the common terminal of the latching relay, either output (A or B) from the latching relay will only show the same output as the switch for as long as the switch is pressed.  "A" would connect to the lock lead pointed out to you. "B" would connect to the unlock lead pointed out to you. If I have time this evening or this weekend, I'll draw a diagram for you if someone doesn't post one first ;). 

the12volt • Support the12volt.com

cheers for taking the time to answer, i will have a another look at relay apps to try and get my head round the workings of the latching relay, if you could spare the time to knock up a quick diagram that would be very much appreciated, as you can probably gather electronics is not my strong point and i don't want to blow anything up

cheers and thanks once again

daz

Here's a picture of a latching relay. This one only has one set of terminals that are either closed or opened. The coil only needs to be energized momentarily and released to change the continuity of the two terminals. So when you energize the coil the first time and release it, the two terminals remain closed. When you energize the coil a second time and release it, the two terminals remain open.

the12volt • Support the12volt.com