I want to install a switch

Froogle · 02-16-2006, 01:55 AM

Hi guys

Currently running a carputer system in my car. It's reasonably slow as it's fanless. Problem is if I start the car up and move for a short journey (like move the car out of the drive to let the girlfriend out and then park it up) it cut's the power to the computer while it's loading. This ends up mucking up the install and windows just loops and won't start.

What I want to do is install a switch so I can put the computer on when I like.

I've got one of these http://linitx.com/product_info.php?c...roducts_id=598 in at the moment wired to the ignition. I don't want to pull the car appart again to change this so is there a way I can install a switch onto one of these wires so I can turn the pc on when I want.

Which wire would I install the switch on ? What type of switch would it be ? You get 2 types. One where you get on or off. Another where (I don't know the exact name) you switch it on for a second to close the connection but it switches straight off again. I guess the same as a normal pc switch ?

cheers

GizmoQ · 02-16-2006, 02:40 AM

You might want to take a trip down to your local Electronics supply store (NOT RADIO SHACK, real electronics) and look for a 3-way SPDT switch that you can install between your ACC line and the M1-ATX. Install the switch on the ACC line going into the shutdown controller. I don't recommend using a momentary switch, I got mine specifically for my tablet but should work with a shutdown controller also. Just make sure the switch breaks the connection before making the next, i.e., completely isolates inputs.

Mine has labels ON-OFF-AUTO and I have it wired to my power supply with constant 12V for on and ACC for auto. This switch allows me to keep the carputer on always (ON), leave it off always (OFF), or let the shutdown controller do its thing (AUTO).

ramy_zohair · 02-16-2006, 04:50 AM

peecee · 02-16-2006, 09:02 AM

Quote: Originally Posted by GizmoQ

Mine has labels ON-OFF-AUTO and I have it wired to my power supply with constant 12V for on and ACC for auto. This switch allows me to keep the carputer on always (ON), leave it off always (OFF), or let the shutdown controller do its thing (AUTO).

This is an excellent idea. Is this a function of all SPDT switches? This would be a great way to implement a valet type function. If you know you're going to be running the car for less than a minute or so, or don't want some valet mucking with your installation, just put it to off so the carpc never even powers up. If this isn't in the FAQ, it should be.

ramy_zohair · 02-16-2006, 09:07 AM

The only problem is i can't find a nice looking 3 way switch!

01black_ac · 02-16-2006, 10:51 AM

Would an SPST switch work for this, or does it have to be an SPDT switch? For my own car computer, I don't see the need to have an "always on" function, since that will be draining the battery. I'd rather just be able to control it as ON so that the Opus or M2-ATX (haven't decided which yet) controls the startup and shutdown, and OFF, so that I can prevent the computer from starting up at all if I'm just pulling the car out of the garage to wash it, or just going to get gas or smokes.

I'm planning to wire my Opus or M2-ATX directly off the battery via a relay to the ignition, and would like to wire a manual switch in there as well. So will an SPST work, or does it have to be an SPDT switch? I guess I don't understand switches and relays enough to know the difference between SPST and SPDT in this kind of application.

'01

ramy_zohair · 02-16-2006, 12:50 PM

SPST will give you 2 options (either ALWAYS OFF or AUTO - opus or m1/m2-atx controlled).

SPDT will give you 3 options (ALWAYS OFF, ALWAYS ON & AUTO) - its a three way switch.

if you move the switch to the middle it is in OFF mode

ramy_zohair · 02-16-2006, 12:59 PM

here is the best setup using a SPDT switch

in 1) the power is switched according to the IGN line (and so startup/shutdown controller)
in 2) the PC will always remain off, even if you move your key to IGN position
in 3) the PC will remain always on, even if you pull your keys out, as the IGN is simulated by a +12V line.

hope this helps

maxxell · 02-16-2006, 01:06 PM

You realize that setting this switch to off wont cut the power to the Opus itself. If you are worried about battery drain, cutting power to the IGN wont do it. I have 2 switches in my car. One is up front and easy to reach which cuts the IGN line so I can take short trips without booting up. The other is more hidden and only gets used to completely kill power to the carputer. I flip that only when the system locks up and the Opus cant shut it down or when leaving town for a while and dont want the carputer trickle-draining my battery.

Food for thought.

01black_ac · 02-16-2006, 01:09 PM

Thanks, that does help to make it more clear. I have a follow-up question... If I use an SPST switch, does it matter if the relay between the battery and the ignition switch is SPST or SPDT? I've found several relays in both configurations, and don't know which to use with an SPST switch.

If an SPDT relay is okay, I'm considering this pair:
http://www.allelectronics.com/cgi-bi...VE_RELAY_.html
and
http://www.allelectronics.com/cgi-bi...VE_RELAY_.html

Here are some pretty nice SPST switches which I've been looking at:

http://www.frozencpu.com/scan/se=Ele...nu_search.html

And this one specifically:

http://www.frozencpu.com/ele-138.html?id=bckv3xZy

Might be nice to mount it inside a lockable console, or even somewhere on the dash, depending on how bright the LED actually is.

'01

01black_ac · 02-16-2006, 01:11 PM

Quote: Originally Posted by maxxell

You realize that setting this switch to off wont cut the power to the Opus itself. If you are worried about battery drain, cutting power to the IGN wont do it. I have 2 switches in my car. One is up front and easy to reach which cuts the IGN line so I can take short trips without booting up. The other is more hidden and only gets used to completely kill power to the carputer. I flip that only when the system locks up and the Opus cant shut it down or when leaving town for a while and dont want the carputer trickle-draining my battery.

maxxell, can you elaborate a bit on the exact configuration of the two switches (types of switch, location in the circuit, etc)

I thought the point of a relay is for the circuit to be open until the ignition is turned on, and then the circuit gets closed and sends the 12V signal to the computer PSU (provided the switch is also set to ON). If the ignition is turned on but the switch is turned OFF, the relay will still close the circuit to the computer, but the switch being set to OFF will keep the computer from powering up or drawing off the battery... no..?

'01

maxxell · 02-16-2006, 01:20 PM

Switch #1: Between battery & IGN line on Opus. When on, the opus acts as normal. It turns on and off based on the position of the key. When the switch is off, the Opus never gets the signal from the car that the key is on so it never sends the signal to the computer to boot up. [When the opus gets power on the IGN line, it just simulates pushing the power button on the motherboard, and pushes it again to shut down]

Switch #2: Between the battery and the 12v line on the Opus. This kills the line carrying all the work-load electricity to the Opus. Sometimes something locks up so that pressing the power button wont work. THat's when you need to do a hard reboot. When I flip that switch, it's the same as pulling the power plug from the back of the computer. It's a last resort, but since you cant hold the power button down to do a hard reboot, it's come in hand a few times. I also flip that switch when leaving town for a while. I usually leave the computer in standby, but when leaving town for more than 5 or 6 days, I do a full shut-down and kill that switch. A bunch of my USB devices dont fully turn off when the computer does. For more info on that, do a search for the Epia USB issues.

ramy_zohair · 02-16-2006, 01:42 PM

if you have the switch on the IGN line, you never kill the power to your powersupply, (this power is always supplied through the 12V line (you have 3 line to the PSU: 12V, ground & IGN) IGN controls the behaviour (startup/shutdown) of the computer. If you want to totally cut the power , you will need a switch on the line between your battery & the PSU.

scott_fx · 02-16-2006, 01:52 PM

Quote: Originally Posted by 01black_ac

Thanks, that does help to make it more clear. I have a follow-up question... If I use an SPST switch, does it matter if the relay between the battery and the ignition switch is SPST or SPDT? I've found several relays in both configurations, and don't know which to use with an SPST switch.

If an SPDT relay is okay, I'm considering this pair:
http://www.allelectronics.com/cgi-bi...VE_RELAY_.html
and
http://www.allelectronics.com/cgi-bi...VE_RELAY_.html

Here are some pretty nice SPST switches which I've been looking at:

http://www.frozencpu.com/scan/se=Ele...nu_search.html

And this one specifically:

http://www.frozencpu.com/ele-138.html?id=bckv3xZy

Might be nice to mount it inside a lockable console, or even somewhere on the dash, depending on how bright the LED actually is.

'01

that toggle switch is an eyesore in my opinion, not stealth and fake carbon fiber is lame.

here is a solution for you though. how good are you at soldering? you can get a momentary switch (like one of those vandal resistant ones on frozencpu. then look up the schematics for "combination lock ic" set up the ic's so that one push of the switch will give power to the relay that is controling the power on, then two pushes will disconnect power completely, and three pushes will put it back to auto. (or some variation of that)

You may need to wire up 3 seperate combo lock ic's but it'ld be the cleanest install. you could even make it completely stealth and use a q-touch ic to make a touch sensative momentary switch.

ramy_zohair · 02-16-2006, 01:53 PM

Why do you keep talkin about relays. they are different than switches. Relays are "automatic" switches. the whole point of using a switch is to manually overwrite what your PSU is automatically doing.
these are examples of SPDT switches. They have 4 terminals and can be set in 3 positions (left, center & right).

so i don't get the point of you using a relay (your PSU already uses one, taking IGN as a input)