Thread: Power switch to the opus

Originally Posted by XMen

Hi,


I want to connect the opus IGN/+/- cables to a switch button, so that the PSU will start only if the button is on 1 and will just down only if the switch is on -, now does this means that i connect the IGN to one side of the button and the IGN from the opus to the other?
and on another note will this allow me to TOTALY shutoff any usb device? meaning if i shutdown the computer and THEN turn the switch button to 0 , does it means that any usb device will be turned off?


Thanks alot,


X.

I'm not exactly sure what you mean but the way I initially wired my Opus is: Accessory wire (switched 12V) on one terminal of the switch (SPST) and the Opus IGN wire on the other terminal. When the switch is closed, my Opus turns on (after a short delay) when the key is in the Accessory or Run position and turns off automatically when the key is in the OFF position. When the switch is open, the Opus stays off regardless of the key position.

I discovered that the Opus 150W will supply +5VSB as long as +12V power is applied, even if the IGN wire is disconnected. According to Opus, this is in line with ATX specs and is needed to support WOL and WOR on the m/b(makes sense since the modem or NIC needs some power to maintain WOL or WOR circuitry). On many m/b, any device connected to the USB ports will remain powered if +5VSB is on which may or may not suit your needs. I didn't need or want any USB devices using up juice so I added an additional shutdown controller before the Opus to cut power to it 2 minutes after I turn off the switch or put the key into OFF position. It would have been nice if the Opus had a jumper that allowed us to switch off +5VSB totally and eliminate the need for an external shutdown controller.

Originally Posted by XMen

Hi,


I want to connect the opus IGN/+/- cables to a switch button, so that the PSU will start only if the button is on 1 and will just down only if the switch is on -, now does this means that i connect the IGN to one side of the button and the IGN from the opus to the other?
and on another note will this allow me to TOTALY shutoff any usb device? meaning if i shutdown the computer and THEN turn the switch button to 0 , does it means that any usb device will be turned off?


Thanks alot,
X.

Your theory will still shutdown if you turn your ignition off. If you actually want to control power ONLY via the switch, then you cannot use your cars IGN line, and you must put a switch between the +12v and IGN lines on your Opus. Obviously if you leave your car and forget to shut it off you'll return to a dead battery!

The opus sounds like the best solution really, I cant see why anyone should choose an alternative aside from price, am I right about that?

Aparantly, it does everything I want in a dc-dc supply, but I was wondering if anyone could tell me how. On my car, the switched 12 volt is on when the car is in acc or run modes, but obviously cuts out when in start mode. The opus apparantly is designed so that it wont cut out during start - but how? If I get into the car, put in the key, and turn it on... the opus recieves the switched power for half a second, and then stops seeing it. Does the opus' circuitry detect this, turn on, and stay on?

I assume it shuts down the computer using the remote soft off function built into atx...

The Opus has three wires. ACC, Battery, and ground. It draws it's power from the battery, and uses the ACC line to know when to send the start-up/shut-down signal to the motherboard.

When you turn the key to ACC it'll startup and then when you crank, it loses power, but the Opus will wait at least 10 sec before sending the shutdown signal. when ACC comes back on after you start the car, it'll cancel the timer and won't send the shutdown signal.

Ah hah a perfect answer. I was figuring it was something along that lines. I just didnt know how it worked mechanically.

So on a really cold day if I crank my car for 10 seconds - computer goes off. Heh. That will never happen of course.

10 sec is the default. you can set it to 10sec, 20 min, 40 min, or 60 min. I plan on setting mine to 20 min, so a quick stop at an atm or gas station won't mean I have to wait for a reboot.

Oh thats right - I hadn't even considered that. Getting out of the car for a nice coffee break at 7-11. I dont want to turn my poor system on and off constantly.

But then again, that means every time I turn off my car when I get home, my computer stays on for 20 minutes unless I press my override shut down switch.

But... I could set it to 10 seconds... and use a feature in my security/remote start system. Some security systems let you arm the cars security system while leaving the car running. I may go that route. Turnin a car itself off and on for just a few minutes isn't a good, I think.

Originally Posted by Kaspin

The Opus has three wires. ACC, Battery, and ground. It draws it's power from the battery, and uses the ACC line to know when to send the start-up/shut-down signal to the motherboard.

Thanks alot for the replies till now..

When you turn the key to ACC it'll startup and then when you crank, it loses power, but the Opus will wait at least 10 sec before sending the shutdown signal. when ACC comes back on after you start the car, it'll cancel the timer and won't send the shutdown signal.

So if i "Y" connect the ACC and the 12v lines to a switch button like:
\ The 12 v and the IGN
\
\
=D The switch button
/
/ The 12V and the IGN
it will do my needs, meaning when the button is on 1 and i IGN it will power the pc, and when i IGN and the switch is on 0 it wont, and neither any usb device will be on if the switch if on 0.
meaning if i want the usb devices to be off after i shutdown ill have the turn the switch to 0. Does this sounds right?

Here is what I plan on doing.

When the car is off and the key is out, the switched 12v (the acc, ign, whatever wire) has no current, but the constant 12v does - as its wired usually through the fuse box and to the battery.

I'm going to tap into that wire and make a simple toggle switch. Since it wont be used all the time, I'm going to just get a simple radioshack piece, and install it under the dash, tucked away.

99% of the time, I am going to want the computer to turn on when I put the key in and put it in acc. 99% of the time, I'm happy with letting the computer shut down automatically when I remove the key.

But, there will be rare times when I want to turn the car on without the carputer to turn on automatically. I want to avoid having it turn on for a few seconds and then shutting it off immediately using its own soft off switch. These times may include when I am doing diagnostic or engine work on my car... there are many times when my car gets turned on and off for whatever reason, and I have no use to use the system.

I can toggle that switch to be off, and not worry about the entire carputer setup for those times. Also - the usb drain in my setup should be minimal, but it does exist - as WOL is going to be a feature that I am interested in. Again, this same toggle switch I can use to turn off the carputer completely, to prevent usb drain for when the car is not in use for extended periods of time, as well as to disable WOL at the location.