Remote Shutdown Circuit - Would This Work?

**owenjh** · 08-28-2004, 11:28 PM

Ok, my idea is this. Making a circuit that enables a computer controlled relay to take over my Accessory Line. Its kind of hard to explain, but bassically I want to be able to leave my car computer on when I leave the car, and control the car PC via WiFi. But, I do not want to leave my ACC wire live as my stereo and all that stuff will be on. I just want the PC on. So, My plan is the picture.

I have gone thru this in my head a couple of times I don't see any problems with it, but I need to know if I need a diode to restrict backward voltage from the second relay going to the first relay.

I will use remote control software to control it, and use a parrallel relay control to power the second relay, that way from my remote console, I could shut it down by just turning the relay off. It would then initialize the shutdown controllers routine for shutting the PC off.

Any idea's thoughts, will it work / wont it work suggestions are welcomed, if you think you can help please reply!!!

Thanks in advance!

**owenjh** · 08-28-2004, 11:35 PM

ahh its so much easyer to explain when I can see the picture without alt-tabbing. I would have to activate the parrallel relay voltage before the shutdown controller initiated the shutdown (5 minutes) that should be enough time to get to my computer and remote console in then click a button. Or i can click the button before I leave my car if I know Im going to be working on it. If you need any more pictures let me know, I can draw more with the whole shutdown controller and what not, but I really think its quite basic if I came up with it :-P

**2nau-t** · 08-30-2004, 05:52 AM

okay i have an easy way then a realy easy way
1. easy way use a 2 ch rf realy board kit found @ http://www.electronickits.com/kit/co...lec/ck1617.htm
this will allow you to remotely turn on you're computer from house
here is a wairing diag

**owenjh** · 08-30-2004, 09:07 AM

I like that idea, for remote turn on, but it wouldn't work in my case (no power on resume)
I guess what my question was would my solution work?
Was the one posted above the easy way? or the really easy way?

**CHUPACABRA** · 08-30-2004, 09:20 AM

Well 2nau-t has a good point but Id leave the power going to the carputer live,and use the remote setup on the power switch of the case. You can hook up the relay to power it off and power it on from in your house. Ive done this but with a car alarm system so I know it works!!

**owenjh** · 08-30-2004, 11:26 AM

$44.95 for an assembeled kit is quite expensive compared to < $10 in relays, although the more I think about this the more I like it.
The only problem is is that I already have the shutdown controller so all that would be needed to be relayed with the RF module would be the ACC line, thus my Accessories would come on, which I don't wan't to. Just the computer needs to come on & I don't really need to start the computer up (it won't any way because of no resume from power loss), just turn it off.
It looks like im going to have to test this circuit and see if it burns a relay up.
I am still considering using the RF module for another project tho: Thanks for the link.

**owenjh** · 08-31-2004, 07:52 PM

Any one with electronic knowledge? i need more help with this still, this is the best way for me to do it!!! im thinking that its not good if you have the voltage of one colliding with the voltage from another? Do I need diodes?

**2nau-t** · 08-31-2004, 08:22 PM

yes diodes would do good but the remote side relay would not be on if you crank you're engine hope you would turn it off
the realy easy way (sorry fell asleep was 4am)

would be to get a timer delay relay that would leave your computer on 30s- 5h after shutdown of engine
http://www.aaroncake.net/circuits/relaytim2.htm
*********************gettitng harder*************************
if you replace s1 with npn transistor then you can turn it off with computer in house but that would require you to be able to interface it with phydgets
http://www.phidgetsusa.com/viewproduct.asp?SKU=1014
if you

for timer delay circuits you can find thousands of variations
dave

**owenjh** · 09-01-2004, 11:37 PM

Yea, i know about the timer delay relays, but you see, I do not know how long I will be working on my PC. When the alarm in my inverter goes off I still have about 20 minutes before complete dead battery and I can use my PC for 2 hours till the alarm goes off. I have remote control software loaded, but I wanted to be able to make an application where I could press the button and it would turn the relay from computer off, therefore cutting the power to the PC and then doing the shutdown procedure... now I look at it there are a few problems with this.. like when PC relay voltage is on, and the ACC is on, this will be a problem right? Im not very good at electronics but am trying to get a better understanding, just need a way to get this circuit working right now :-P

For the relay board, I was just going to make my own by googling for it. I know alot of people interface thier x-mas lights with parrallel ports so this shouldn't be a problem, its the circuit that will be.

**owenjh** · 09-01-2004, 11:43 PM

That phidgets board does look good. Very easy to program in visual basic too. If i used this as the computer controlled relay board would I still have to use diodes? and the such?