Goddy

Im considering to startup my laptop using the antenna pulse from the HU. Maybe some people know how the antenna pulse of most HU's works. I assume it gives a short pulse to activate an external powered antenna.

I'd like to use this pulse to switch my laptop on. I extended to standby button to the front so i can 'remotely' get my laptop out of standby mode using the button. But i like this to go automaticly when i start my radio. some questions are, how is the pulse mechanism working? is there a pulse, how long is the pulse or a continues power, etc. I think the best way to do this is using a relais.

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ACHIEVER

It's not a pulse, but rather a constant + feed. (very low current too)

Goddy

So i assume this isnt the way to go, because in this way, the button will be always pressed

Goddy

I thought of a solution, but i dont know how to build it. Maybe i can use a relais to switch the standby wires when the HU is on, and switch also (for like 0.5 sec) when the power is off. I suggest i also have to use a capacitor.

Perhaps some one is really good with electronics and could build me a wire-sheet?

WhiteRabbit

no good. your computer would only come on when you turn on the radio. unless you are using an fm mod, then it might be a pretty good idea!

but you can find many, many schematics, both online and at your local library for how to take a cosntant input and create a pulsed output. the antenna out would fed a constant 12 volt source when you turn on the radio (but not the cd player). your circuit would take this input then output a pulsed voltage. Then, when you turned off the radio (or switched it to CD or tape, etc) the 12 volt constant source would switch off. the circuit would see this change, and output a pulse again.

even those 300 in 1 electronic project kit things you can get from radio shack have schematics in them.

if you are having problems finding a schematic, try looking up the forrest mimms books inside your neighborhood radioshack. they might have something you want, too.

Goddy

In your story i assume that the antenna/aerial cable only works when you are switching to AM/FM mode. But i doubt that, because when you are having an amp, you are also using that cable to switch the amp on and off, right ??

mbuchman

You are referring to the remote turn on wire. Most people run this from the head unit. Much like the antenna wire, except that when the car is on, low current power is sent through this wire, regardless if the radio is on. It is just telling the radio that it COULD be on if it wants to be

Being lazy and just running it form the antenna would be a bad idea, as previously posted, because if you turn off your radio, the computer would go off too. Course, most of the time, I guess you would want both on or off together, so you could use it anyway.

Matt

Goddy

Yes, in this way, when i turn off the ignition the radio would go off (and then so would the laptop). I see no use of the laptop being on and the head unit is off.

I have to measure the blue wire to see what is really happening and then i could think of some solution.
Thanks for the help so far

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WhiteRabbit

startup and shutdown times. doesnt matter if its suspend, hibernate, or actual shutdown. takes time.

some radio's shut off when you pull the CD. yours might not. again, doesnt matter.

sucks when you turn off the radio for ANY reason for about a minute, or even jsut a second, and now you have to wait for your computer to go through the startup and shutdown motions. its time away from you listening to music.

tie that pulse generator to ACC. car is on, you have access to music. car off, computer wont drain your battery. done.

thats how I see it......

Goddy

Standby only takes a few seconds and starts immediatly where it ended, far much better than shutdown/startup or hibernation. The laptop can be in standby mode for days on his own powersupply!! It takes max 5 seconds to get back from standby and goes in standby within 2 - 10 seconds (depends on how many progs are running).

So i dont see that as a problem. The laptop is hooked to the sigarette plug, same as the lilliput lcd. The sigarette plug is switched by the ignition and so is the head unit. So when the key in the car switches everything (and soon i hope my laptop too).

WhiteRabbit

sounds like a good system, I would probbaly leave it like that

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