Triggering pro audio sub amp on/off for HT

[m R g S r]

How would you trigger a pro amp on/off with your receiver that doesn't have a 12v trigger? I thought the receiver had one, and was going to use a 12v solid state relay, but turns out it doesn't.

I want my sub amp to come on off with just remotely turning on the receiver.

I have:
Marantz sr5006
Qsc mx1500 quiet fan mod for HT use
Mini DSP

The mini DSP is powered off the USB of the receiver, so that comes on / off with the receiver.

I pulled the power switch from the QSC and ran wires to the back for the switch, so I can mount a relay in the future if that will work. It's 120VAC switch

I'm thinking a 5V solid state relay which grabs power from the mini DSP, which would be powered up when the receiver turns on. I'm just not sure if there is enough power from the USB to operate a relay, and if I can find a relay that will have a high enough amperage rating for the QSC amp. (As far as I can tell, the power comes in through the main power switch first on the QSC, so it needs to be able to handle 15amps or so)
Any suggestions for good solid state relays?

I Also don't know if the external power connection and the mini USB in on the mini DSP are connected in parallel without a diode?


Any other CHEAP solutions for simply getting the amp to power on when I turn the receiver on?

 

[m R g S r]

I guess I could use this, but for future setup I'd like my sub amps on a separate circuit (outlet) from the receiver...
ZuniDigital ZG10222B-27 10 Outlet Digital Smart Green Surge Protector (Black):Amazon:Electronics

 

[tb46]

Hi,

A simple somewhat brute force method is a simple contactor (120VAC coil voltage):

Mars GE 18002 Magnetic Line Contactor 3ARR8 2 Pole 30A | eBay

http://www.ebay.com/itm/DEFINITE-PU...461?pt=LH_DefaultDomain_0&hash=item2ec238edfd

Regards,

 

[Djim]

Hi mRgSr,

You can use the USB output from the receiver to power a LED that is attached to a light sensitive relay-switch.

 

[m R g S r]

Link to any that can handle 120VAC 10-20a?

 

[m R g S r]

Tb that's a 120vac coil?
I've used contactors before in heavy duty applications three phase machine powering etc but never saw as low as a 5v coil on them...

 

[Djim]

If you have a 12V system link connection on your receiver you can use:
Simple Relay Board

 

[m R g S r]

That would have made all this easier. There's no 12v trigger of any kind on it.
I originally thought there was and was about to order the relay i had picked out (12v, zero cross, 120V 20amp) but I decided to double check And there is no trigger. Grrr

 

[Djim]

Lol, yeah I know how it works. For the last 25 years they always has such trigger.... and now after 25 years you need it for the first time and now there ain't...
I guess you are still under the warranty period, I guess, so getting internal 12V is not really an options either. Well, the photo/light sensitive switch + USB-led is still an option.

 

[Djim]

Light/Dark Relay Switch Kit with TR

 

[Cokewithlime]

Simple here's what I use - $22 at your nearest Wally mart

Works just like they say

Amazon has there own take on it as well

 

[Yoctopuce]

I'm thinking a 5V solid state relay which grabs power from the mini DSP, which would be powered up when the receiver turns on. I'm just not sure if there is enough power from the USB to operate a relay, and if I can find a relay that will have a high enough amperage rating for the QSC amp. (As far as I can tell, the power comes in through the main power switch first on the QSC, so it needs to be able to handle 15amps or so)

If you are looking for an USB driven relay, you may want to have a look here:

Yocto-PowerRelay - Tiny USB relay (SPDT) for switching mains powered appliances

These can have customized firmware making them switch as soon as they are powered. Unfortunately, they can handle 5A only. But you can use them to drive a much bigger relay.

 

[tb46]

Hi m R g S r,

Post #1: "...I pulled the power switch from the QSC and ran wires to the back for the switch, so I can mount a relay in the future if that will work. It's 120VAC switch."

That's where you could tap in for driving the 120VAC coil of the power contactor. (Using a contactor will give you a great deal of freedom as to the amount of power you are switching.)

Or, you could drive the power contactor coil of a 5VDC relay connected to the 5 V line from the USB plug (as Djim and Yoctopuce pointed out), with the relay switching the 120VAC for the contactor coil, e.g.: Relay 5V DC SPDT Power 2A 250VAC 10pcs | eBay

You might want to put a reverse connected diode accross the 5V relay coil to reduce coil related spikes on the USB 5V line.

Or use something as Cokewithlime suggested, that should work just fine.

Regards,

 

[Djim]

And don’t forget a resistor in series with a capacitor, both across the 110V contacts of the relay-switch, to prevent arcing that will damage the contacts.

 

[m R g S r]

Hi m R g S r,

Post #1: "...I pulled the power switch from the QSC and ran wires to the back for the switch, so I can mount a relay in the future if that will work. It's 120VAC switch."

That's where you could tap in for driving the 120VAC coil of the power contactor. (Using a contactor will give you a great deal of freedom as to the amount of power you are switching.)

Or, you could drive the power contactor coil of a 5VDC relay connected to the 5 V line from the USB plug (as Djim and Yoctopuce pointed out), with the relay switching the 120VAC for the contactor coil, e.g.: Relay 5V DC SPDT Power 2A 250VAC 10pcs | eBay

You might want to put a reverse connected diode accross the 5V relay coil to reduce coil related spikes on the USB 5V line.

Or use something as Cokewithlime suggested, that should work just fine.

Regards,

The coil on the contactor would only be provided power via USB from the receiver turning on and off. And that wouldn't be sufficient.

The switch on the second amp, the qsc, the one I want to Come on and off with the receiver, is 120vac.

For now I picked up a master/slave power strip. That will suffice for the time being until I upgrade to a dedicated theater with dedicated power, and some large horns / multiple sub Amps.

Thanks for he help guys, ill use this in the future!