Wiring question.

**kuwupt** · 01-25-2006, 03:17 AM

I did a search but could not find what I wanted so I was hoping one of you gurus could help me out.

I'm trying to wire my Lilliput to a DPDT http://www.radioshack.com/product/in...tId=2049722&cp
so that when I turn off the ignition the screen goes off. I know there needs a igniition power wire, a 12v to LCD and a ground but I dont know what gets wired to which points on this relay. I know I read about this when I put a carputer in my first car almost a year ago but cant seem to find it now.

Thanks.

**gospeed.racer** · 01-25-2006, 03:35 AM

Need the pinout to help.
Its not listed online

I personally would have just used a standard old 20-30A Bosch style relay (spst or spdt)

**kuwupt** · 01-25-2006, 01:35 PM

Would this help?

http://lims.mech.northwestern.edu/~l...ME395/dpdt.gif

http://www.futurlec.com/Relays/GR110PIN.shtml

**gospeed.racer** · 01-25-2006, 07:31 PM

Just hook up the screen normally and verify it works. Then, cut the power wire going to it, and splice in this relay. It will break the contact when the ignition is off, and restore power when back on.

I assume this is all you want it to do, right? The DPDT is overkill for just that, but will work fine.

**kuwupt** · 01-26-2006, 01:10 AM

hmm.. where does the power from the opus go to? Almost a year ago there was a write up about this and I beleive it said that there were 4 connections.
1) opus + to DPDT
2) LCD + power cable
3) 5v Ignition
4) Ground

If this is over kill and since I'm confused about this would you be able to tell me how to wire it with a relay you suggest / used to be able to do what I want? ie. when ignition and power supply is on switch on my LCD and when ignition is off switch off my LCD.

Thanks.

**gospeed.racer** · 01-26-2006, 01:25 AM

Ahhh you didnt say anything about an Opus.

All my drawing would do is allow power to the screen when the ignition is on, and turn it off when the ignition is off. If there is a wire on the Opus you can use as a trigger, then connect it to the coil of the relay. Then whenever the opus is on, the lcd is on.

All a relay is essentially is an electric switch. You tell it to turn on by applying power to its coils, and when the coil gets power, it completes a circuit just like a switch.

Not sure why they want 5v anywhere on the circuit, unless that is what they were triggering the relay with? Are you running the screen off the Opus for power?

**kuwupt** · 01-26-2006, 03:56 AM

yup, Im powering the Lilliput off the Opus, just wanted to be able to switch the screen off when ignition is off because I did the auto on hack on my lilliput and didnt want my screen to be on for 20min till the pc shutdown. How would you suggest I do this. Bear with me cause I'm a complete noob at wiring relays etc..

**gospeed.racer** · 01-26-2006, 12:08 PM

do it just like I said in the post with the drawing then. Make sure everything works, then clip the power wire going from the Opus to the screen and install the relay. Very simple and will do exactly what you want (key off=screen off, key on=screen on). Forget all the other stuff you had read.

**zac_haryy** · 01-26-2006, 12:39 PM

Is there a relay that would do this sort of thing but when you turn the ignition to the on position it would switch the power to my laptop on and then it would switch it off when the ignition is in the off position. The relay would need to be a different relay (if they even make them). It would have to (when you turn the ignition to on) switch the relay to on and leave it there for 5 seconds and then it would switch back off. The relay would have to do the exact oppisite for it to turn off. Thanks!

-haryy