Controlling your power setup remotely

**auto_robotics** · 10-06-2004, 10:52 PM

I've heard a few people on the boards talk about being able to switch off power to their computer from the dash. How are people going about this?

Are you guys:
1) controlling a relay that cuts off or connects power to the inverter / DC-DC power supply
2) taking the inverter's switch out of the packaging and "bringing it up front"
3) figuring out how the inverter switch works and then making a switch on the dash be an additional pull-up/down to what I guess would be an "ENABLE" logic line for the inverter circuitry
4) something else?

Also, that same question to turning off / on and resetting the computer:
1) will the computer boot reliably when the power is reconnected?
2) if not, what's the best way to control the power button and reset from the drivers seat

Thanks very much!

**kiltjim** · 10-06-2004, 11:03 PM

Alot of guys are using the OPUS power supplies. I am using an inverter with a relay hooked to the positive terminal on the inverter. This is probably the easiest was to do it. I haven't ever seen an inverter that this wouldn't work on.

As for the computer, a simple momentary switch wired to the motherboard wil get this done.

I'm using a laptop, so the wiring had to be directly soldered to the computer, and then wired to the cabin.

The computer does not like having power cut abruptly. If you are using a desktop, go with an OPUS. They seem to be the easiest to work with. If funds are short, you can use an inverter, but you must shut the computer down before cutting power. As for power up, I have two different switches to use before getting the computer on. There have been a few different methods of getting your computer on posted here. Just search and you shall find.

**auto_robotics** · 10-06-2004, 11:21 PM

Awesome. I was thinking of using the Stinger 80A relay ($15) to handle the inverter power supply to avoid its constant half-amp or so draw. The on/off control on the relay could come from a SPST switch wired to +12V battery. Sound good or does the relay control need to have a pull-down resistor? I'm not really sure how they work internally. This control wire takes no real current right?

I'm using much more than OPUS's 150W, and unfortunately more than the upcoming 220W one too, so I think I'll give the mom-switches a try and be careful.

Thanks for the input kiltjim.

**Deliriousvision** · 10-07-2004, 04:11 AM

i simply have the relay hooked up to the switch that turns my inverter on and off, so that there isn't too much current going through the relay. Then the relay is hooked up to a switch on the dash to easily turn it on and off.

Now, for the laptop, couldn't you wire 2 simple relays up to control the computer, to have it shut down when the car is turned off. have a relay that stays disconnected until there is power to it, then it switches (not sure what kind its called, either normally open, or normally closed) use that for the power switch, and have another wire comming off the laptop (one from the hard drive cable maybe?) and have that wired to the relay for the inverter, so that when the "hard drive cable" loses power (car turned off) it cuts power to the inverter.

let me know what you think about this, i think it seems pretty simple, kinda just came to me when i was reading your post.

**Bravellir** · 10-07-2004, 05:26 AM

Originally Posted by auto_robotics

Awesome. I was thinking of using the Stinger 80A relay ($15) to handle the inverter power supply to avoid its constant half-amp or so draw. The on/off control on the relay could come from a SPST switch wired to +12V battery. Sound good or does the relay control need to have a pull-down resistor? I'm not really sure how they work internally. This control wire takes no real current right?

I'm using much more than OPUS's 150W, and unfortunately more than the upcoming 220W one too, so I think I'll give the mom-switches a try and be careful.

Thanks for the input kiltjim.

If you must go with an inverter, you could do as I did, and use a shutdown controller like the ITPS.

It connects to the battery and switched 12v ( maybe from HU ) and outputs to the relay and to the motherboard power switch.

When it detects the switched 12v ( you turn on the car key ) it powers the relay and sends a pulse to the motherboard turning on the pc. When it detects no switched 12v ( you turn off the car ) it sends a pulse to the motherboard turning off the pc and 45 secs after it cuts power to the relay.
The relay should be connected to the 12v from the battery to the inverter.

If you need to have the pc running with the car turned off, you can connect a switch with tree positions on the switched 12v line so you could have off,
auto ( connected to switched 12v ) and on ( connected to 12v ).

The Opus and Carnetix are full solutions, because they achieve all of this without trouble and they survive crank. The solution I'm using does not help in surviving crank. If your car battery/Inverter combo is ok - the minimum input voltage for the inverter is higher than the battery voltage during crank - 10v in my case - it will survive.

Do a little search because there are very god treads on this topic, with schematics and all.

**HummDinger** · 10-07-2004, 06:52 AM

You can simply hook up a mommentary switch from your dash to the on/off button on your computer. This will shut it down softly and you dont have to worry about any lost data. Cutting the power is a popular way just because once you restore power the wake on lan option takes over and will turn on the computer for you. The switch idea though is a much better route to go for a smoother running system.
When using the switch idea, you can use a relay switched from a 12v source on a molex connector in side you computer. So if you are using an inverter it will cut the power to it once the computer is shutdown. This is similar to how a shutdown controller will work. I used this idea in my install for quite a while and it worked great.

**Deliriousvision** · 10-07-2004, 01:26 PM

Originally Posted by HummDinger

You can simply hook up a mommentary switch from your dash to the on/off button on your computer. This will shut it down softly and you dont have to worry about any lost data. Cutting the power is a popular way just because once you restore power the wake on lan option takes over and will turn on the computer for you. The switch idea though is a much better route to go for a smoother running system.
When using the switch idea, you can use a relay switched from a 12v source on a molex connector in side you computer. So if you are using an inverter it will cut the power to it once the computer is shutdown. This is similar to how a shutdown controller will work. I used this idea in my install for quite a while and it worked great.

yea, thats excatly what i was trying to explain, i think this works best for laptops, since you can't install an opus or other power supply in them. Simply have a momentary relay hooked up to the computer power switch on the mother board (or have a simple momentary switch, but then the computer could get left on for extrended periods of time) so that when the ACC wire loses power, the car is turned off....it trips the relay and initiates the shutdown sequence, and once the computer shuts down it trips another relay that kills the inverter............that works for turning it off, but i dont know how to get it back one, you have to have a seperate realy that turns the inverter back on when the ACC line gets 12v, but then if that relay is connected the inverter wont shut down when the computer shuts down..............you could add, yet another relay...(lol, this is getting out of hand) that disconnects the relay that turns the inverter on when the computer gets power. alrite lemme see if i can break this down...

turn the key on Relay 1 turns on the power inverter and Relay 2 pushes the power button on the computer. once the computer gets power Relay 3 disconnects Relay 1

turn the key off Relay 2 initates the shutdown sequence, and when it is done Relay 4 switches the inverter off.

okay, im kind of confused right now.......can anyone make sense of that?