I have a dilema..
I am building a system this winter (dont try to talk me out of the products, I have heard and love them)
Infinity = Kappa Perfect series 4x6 6x9 and two 12" subs in a box made for our cars. I will be using two xplod amps (i can hear the groans now, but i can get good deals on xplod amps and i have been using them for a couple of years now with no problems whatsoever)

Here the clincher.. Im not using a deck. I have a brand new HP laptop with media center. I have all of the mounting and the power wiring figured out. I am going to buy a decent (not really expensive) usb soundcard that has 4.1 audio to it. I will figure out configuration when i get it in. My problem is i dont know how to turn on the amps...because there is no remote turn-on wire.. does anyone here know of a way for me to get this to work? I really dont want to buy a deck just so i can relay the audio from the laptop to the radio to the amps.. that's $300 i can put into other things.

So is there any way i can have the amps turn on and recieve and use the signal i will be sending from the laptop? (aka, will running the remote fromt the remote port on the amp to the power port on the amp and having a switch work?)

Thanx

Rabbitt

 

find out if a USB port provides enough current to turn on a relay. If it does, you can use the power from the usb port to turn a relay that allows 12 volts to pass to the remote pin on the amp.

 

yah.. that would work pretty nicely, i'll check that out.

So, with amps, the romote relay is no specific signal, just a small 12v source of power? that's all it needs? i'll check out the usb idea, but if all i need to do to turn on the amp (technically) is have a 12v power source going to the remote, then i will at least have a good deal of options.

Thanx

Rabbitt

 

you are correct sir. but not TOO small a signal, there are limits. using a relay you'll have a very nice trigger and it'll work fine.

bmoney

 

If all you need is a 12v power source going to the amps to turn them on, all you need to do is put in some sort of switch, whether it be a push button switch or a toggle switch and hook it up to any 12v power source, put in a fuse and this will turn your amps on and off with the switch. It should be that easy.

 

yah.. thats what i was thinking.. push button sounds good to me.. but thats not gonna happen til after xmas.. sooo..

 

what about simply letting the vehicle do it? the brown wire in the ignition harness under the dash (the thicker 14 awg wires) is what turns your factory radio and accessories on (key forward AND back). why not run a wire (with fuse) off this wire and let the amps come on with the key?

bmoney

 

It is that easy, but if you can have it turn on with your computer, it would be more useful.

 

You can also use your laptop's external keyboard/mouse connector (mini-Din aka PS/2) for +5 volts. I just found a pinout page; see http://www.networktechinc.com/technote.html for more info. (Saves me from trying to explain the pin positions!)

The current of a USB power is small- it's bus voltage, so max is 5 unit loads- a unit load for USB is 100mA. Exceed 500mA and you're in trouble!! Normal usage is 1-2 load units (100-200 mA).

Keyboard/Mouse connector max is 100 mA. This is why you shouldn't unplug or plug in a keyboard/mouse while your computer is on; you can generate a surge that will fry the keyboard/mouse driver.

Check http://www.allelectronics.com for relays, and there's always Radio Shack. Since your amplifiers need some sort of a current for turn-on voltage, make sure the relay is rated for "at least" the amperage that you need to send. Example, a relay that's rated 10 amps doesn't mean it takes 10 amps to turn the relay on; it means the contacts can handle 10 amps.

AND FUSE EVERYTHING!! On the coil side of the relay, between the USB connector and relay, put a 0.5 amp quick-blow fuse in a fuse holder. If you use the keyboard/mouse port, put a 0.1 amp quick-blow fuse in there. Also put a fuse on the switch side of the relay, between +12 battery and your amps.

Oh- the coils are rated in ohms. So since mouse & keyboard & USB all put out 5 volts, divide 5 by the ohms of the relay coil. That will give you the amps needed to turn the relay on. Example, 150 ohm SPST relay coil, 5 volts / 150 ohms = 1/30th of an amp = 0.033 amps = 33 mA = "Safe".

 

thats true, but i also want to keep the amount of ports plugged into my laptop down, because the laptop isn't going to be permenantly in the car, just when i am out and about (which is a good amount of time considering its my daily driver). But having the relay turn on with my laptop would be pretty damn sweet tho...

 

Look at the product below:

http://www.pac-audio.com/products/trigger.htm

Its solid state (relays take alot of juice, you can take the 5 volt bus mentioned).

Keep in mind running it off the ignition means your amps are on all the time, running it off yoru computer might mean that if your computer goes into sleep mode other stuff can happen.

Juan

 

A FRIEND OF MINE JUST USED A TAP FROM HIS LIGHTER BECAUSE ITS ONLY ON WHEN THE CAR IS ON... THAT MIGHT WORK.....

 

Although using the USB port was sounding very good, I think the link that OldOneEye posted would be even better.
You could signle it with the speaker wires. You could have some form of Y connector or use the rear channels of the 4.1.
This would also mean that only two things have to be plugged into the laptop (power and sound out).

 

a friend of mine used the Caps Lock.