Remote start for DIY sub amp - Is that possible?

[Denis.BR]

Hi. My question is quite simple, but since I'm a newbie in the Home Theather world I need some help. If it is posted in the wrong forum, please redirect.

I have a Onkyo receiver, a passive subwoofer and a DIY amp that I was using in my computer.

The Onkyo receiver have only a sub pre out, with no switched AC outlet.
The DIY amp have only a on/off switch.

With this setup, everytime I want to listen to my system I have to manuaally turn the DIY amp on mechanically by flipping the switch AND turning the Onkyo receiver on via remote control.

Is there any way to automatically turn the DIY amp when I turn the receiver on?

I was wondering if there is any way to keep the DIY amp in Stand By mode and turning it on when there is a signal in the sub pre out, or use any available signal in the receiver to turn a relay on and the relay would turn the DIY amp on.

Thanks in advance for any help!

[janneman]

Yes, there are circuits that sense when a signal is coming in and then turn on the mains. They normally turn off the mains a few minites after the signal disappears.

I don't have any specific one handy but I'm sure a google search will turn up some. Look for something like 'signal activated switch'.

Edit: there's one here: http://www.electronicsforu.com/elect...er%20Amplifier

jd

[star882]

http://sound.westhost.com/project79.htm

[Denis.BR]

Thank you ujanneman and Star. I wasn't googling for the right keywords I guess...

I'll try the first project, it seems to my that it is more reliable and have more adjusts than the other ones that I found on google.

[AndrewT]

R3 & R4 are matched.
If the left and right inputs are out of phase the first IC will output a zero signal.

Change one of the resistors to 16k.

[Denis.BR]

Andrew, I'll use it only for subwoofer signal, so I won't use both resistors.


Another question:Can I use only the MJE13005 connecting the base to the 1K resistor?


Bottomline: the darlington bridge is used when you need large current passing trough the transistors. I need to use a relay to switch the AC power supply, so I Ineed only a few miliamps.I didn't find the SL100 in my local electronic store and I'm not in the mood to go there again to find a replacement.

[Everlast]

Maybe it is against the "DIY" way of thinking, but might I suggest something like this -

Craftsman Auto Switch
http://www.sears.com/shc/s/p_10153_12605_00924031000P

I remember seeing similar items years ago that were used to turn on / off your monitor when you turned on / off your computer.

I am all for "DIY", but sometimes it is just cheaper, safer, easier to just buy an existing product that will do the job you need.
I am a new member of this forum and appologize if this suggestion is not appropriate.

Thanks

[Denis.BR]

nice gadget, unfortunately I never found nothing similar here in Brazil

[dangus]

X10 remote switches aren't automatic, but you could switch both the receiver and sub on together using an Appliance Module. If you get some "lamp modules", the remote control dimmer function is a nice luxury.