or Connect
AVS › AVS Forum › Audio › DIY Speakers and Subs › DIY switched outlet
New Posts  All Forums:Forum Nav:

DIY switched outlet

post #1 of 31
Thread Starter 
I want to make a switched outlet for my Behringer EP4000. I want to use the 12V triggers from the rest of the equipment to toggle a relay controlling just the sub amp.

Will this work?
http://www.parts-express.com/pe/show...number=075-124
post #2 of 31
Here is a pretty extensive thread.
post #3 of 31
The 12v trigger from your AVR will not have enough power to energize coil of the relay. It would be best to use a 120vac relay and use the switched outlet from your AVR to energize the relay. Just ensure the relay contacts are rated for the load of your amp.
post #4 of 31
His AVR trigger should have enough power to energize it. 160 ohms/12 = 75 ma. Most AVRs have at least 100ma for trigger.
I built something like notnyts except I used this relay. It takes 100ma to energize the coil, is rated for 20A contacts, and is DPDT so I can trigger 2 amps on 2 different circuits with 1 trigger output. My AVR is only rated for 100ma trigger current but I have had no problems since making it ~1 year ago.
post #5 of 31
Thread Starter 
Thanks for the responses!

Looks like Notnyt used SSRs and thats different from the one i mentioned.

Questions:

1. Is the one Notnyt used better than the one I referenced?

2. Will the one i referenced work?

3. Will another from PE work better? (i already need to place an order with them).

4. Whats up with the heat sink? Im thinking the relay builds heat that should be dissipated? Is thi necessary for all relays?

5. What are the advantages of solid state over conventional?

Thanks for the help guys!
post #6 of 31
Quote:
Originally Posted by NicksHitachi View Post

Thanks for the responses!

Looks like Notnyt used SSRs and thats different from the one i mentioned.

Questions:

1. Is the one Notnyt used better than the one I referenced?

2. Will the one i referenced work?

3. Will another from PE work better? (i already need to place an order with them).

4. Whats up with the heat sink? Im thinking the relay builds heat that should be dissipated? Is thi necessary for all relays?

5. What are the advantages of solid state over conventional?

Thanks for the help guys!

1. It says he updated to a mechanical relay but it has a higher coil resistance than the one you selected so it requires a little more current from the trigger output. I=V/R so when selecting a relay, you know it's 12v for the DC so just find the coil resistance and you can calculate the current required.

2. The one you referenced will work if you are switching 10 amps or less and the 12v trigger output can provide 75mA.

3. Don't know what they have...

4. Generally the data sheet will recommend a heatsink when it is needed. Heatsinks are often needed for SSR but not mechanical relays. The only piece in the mechanical relay that is really generating heat is the DC coil and that is only 12V*.075A= 0.9W in your selected case. Not too power hungry.

5. SSR are not mechanical and thus have higher reliability. They can also switch higher loads and the DC trigger uses very little current.

The one you are looking at is DPDT just like the one haanjamin uses so you could switch two things on in the future. I would say double check the trigger output can supply atleast 75mA and that your sub uses less than 10 amps.

Edit: Almost forgot the advantage of mechanical relays! They make a little click noise when they turn on that is quite satisfying (or annoying?).
post #7 of 31
Any ideas how to make something like this work on a Pioneer VSX-1021? There's a 5v USB plug, but otherwise I don't see anything to trigger a relay.

post #8 of 31
Wouldn't something like this http://www.sears.com/shc/s/p_10153_1...G2#reviewsWrap

work? Plug receiver in as main, run power amp as accessory, turn on receiver, power amp is automatically powered.
post #9 of 31
Quote:
Originally Posted by mpenton View Post

Wouldn't something like this
work? Plug receiver in as main, run power amp as accessory, turn on receiver, power amp is automatically powered.

Interesting device, but one of the reviews said it wasn't sensitive enough when using it with his TV. I'm guessing it needs a fairly large current draw to activate.
post #10 of 31
I do not know what the "control" output is but you could see if the manual says anyting,

You could also just use a Smart Strip (search Amazon or whatever).

One other drawback with mechanical relays is that the coil generates a voltage spike when changing state. A capacitor will help control it, but it is possible the spike could damage the trigger output. That and the current demands would cause me to not use a mechanical relay without a buffer circuit to drive the coil.
post #11 of 31
Thread Starter 
Quote:
Originally Posted by mpenton View Post

Wouldn't something like this http://www.sears.com/shc/s/p_10153_1...G2#reviewsWrap

work? Plug receiver in as main, run power amp as accessory, turn on receiver, power amp is automatically powered.

Sub amps are on dedicated power line, so no.....
post #12 of 31
Thread Starter 
Quote:
Originally Posted by DonH50 View Post

I do not know what the "control" output is but you could see if the manual says anyting,

You could also just use a Smart Strip (search Amazon or whatever).

One other drawback with mechanical relays is that the coil generates a voltage spike when changing state. A capacitor will help control it, but it is possible the spike could damage the trigger output. That and the current demands would cause me to not use a mechanical relay without a buffer circuit to drive the coil.

Smart strip wont work with dedecated line...

You obviously know more about relays than me It sounds like SSRs might be the way to go then and just eat the shipping cost......
post #13 of 31
Quote:
Originally Posted by DonH50 View Post

I do not know what the "control" output is but you could see if the manual says anyting,

You could also just use a Smart Strip (search Amazon or whatever).

One other drawback with mechanical relays is that the coil generates a voltage spike when changing state. A capacitor will help control it, but it is possible the spike could damage the trigger output. That and the current demands would cause me to not use a mechanical relay without a buffer circuit to drive the coil.

I'm not running a dedicated circuit for my sub amp, so the Smart Strip would work fine for me. Thanks for the idea.
post #14 of 31
Quote:
Originally Posted by NicksHitachi View Post

Smart strip wont work with dedecated line...

You obviously know more about relays than me It sounds like SSRs might be the way to go then and just eat the shipping cost......

Hmmm - I'm not remembering the specifics for why I chose NOT to use a SSR for my power distribution box... I think the problem is that they need HEAVY heatsinking if you plan to pass any real current through them. I would not recommend their use for something as power hungry as an EP4000 amp. A preamp, maybe - a power amp, No.

Have a look at my DIY power filter for the relays that I used - I think I ordered them from Digikey or Mouser.

It won't win any awards for being physically tidy, but it does a great job at switching on only what I need for movies vs music, time delayed power up, sequencing, filtration, and surge protection.
post #15 of 31
Thread Starter 
Quote:
Originally Posted by Eric2000 View Post


Hmmm - I'm not remembering the specifics for why I chose NOT to use a SSR for my power distribution box... I think the problem is that they need HEAVY heatsinking if you plan to pass any real current through them. I would not recommend their use for something as power hungry as an EP4000 amp. A preamp, maybe - a power amp, No.

Have a look at my DIY power filter for the relays that I used - I think I ordered them from Digikey or Mouser.

Hey Eric,

Does it matter that the relays are only rated 12v?

Thats good idea i have the parts for the "felix" diy conditiner laying around i might incorperate that into my design......
post #16 of 31
The relays operate (coil energizes) with 12VDC. This controls the opening/closing of the heavy-duty current carrying contacts. The relay itself can switch 270VAC at 30A - well beyond what I need for my application.

The total current draw for my theater system is about 20-22A and I've been using this box for over a year with absolutely no trouble.
post #17 of 31
I was just re-reading the datasheet for the relay that I used in my power distribution box and it appears they make a model that will work with a 5vdc trigger voltage - making it appropriate to use in a USB jack on your AVR. The total power draw for the relay is 1.7w, so it shouldn't "over draw" the power supply for the USB jack...

Another possibility (you need to verify how it functions on your AVR) is to use the 1/8" jack on the left for your infra red controller input. An IR receiver has three legs: +12vdc, 0v, and the IR signal carry. In some AVRs, the +12vdc might always be there, in others, it might be switched on and off with the receiver. Get a jack and check with your volt meter.

One reason I really like the relay that I chose is that its a dual pole, so when something is power off, there is no possibility for current flow at all. The solid state relays have some small bleed-thru voltage at all times. Also (as was pointed out above), mechanical relays have this very satisfying "click" as then open an close so you can easily verify that they are functioning properly as you are building/testing your project.
post #18 of 31
Thread Starter 
Quote:
Originally Posted by Eric2000 View Post

The relays operate (coil energizes) with 12VDC. This controls the opening/closing of the heavy-duty current carrying contacts. The relay itself can switch 270VAC at 30A - well beyond what I need for my application.

The total current draw for my theater system is about 20-22A and I've been using this box for over a year with absolutely no trouble.

Ok, sounds good. The spec sheet quoted contact ratings at 30A at 12V and I wasnt sure how that affected the rating.

Ill lookup the one with 5v signal and see how it might work.

Thanks!
post #19 of 31
Quote:
Originally Posted by NicksHitachi View Post

The spec sheet quoted contact ratings at 30A at 12V and I wasnt sure how that affected the rating.

That threw me at first as well. The Digikey web page indicates 30A at 12V, but they are mixing ratings figures so the data is misleading. If you click through to the PDF document, you'll see that the 30A rating for the contacts is at 277VAC and the 12v rating is the coil rating.
post #20 of 31
My subs are on a dedicated circuit as well. I bought an X10 transmitter that takes my AVR's trigger output and sends a signal to two remote appliance switches. The signal seems to manage finding its way to the subs and works great for me. Another option, perhaps... The Home Automation Store has good prices.

There are also power strips that take a 12V trigger signal.

A SSR to handle 20 - 30 A will indeed need a good heat sink...

For a mechanical relay I would probably build a little transistor circuit, or maybe use a line driver, to buffer the relay from the AVR and call it a day if I were building something. Of course it would need a power source, perhaps from a wall wart (I have a box full and you can buy them cheap). Last time I did something like that I also rigged a little delay circuit so the relay would wait a few seconds before turn-on, but turn off instantly to reduce the chance of surges and pops causing problems.
post #21 of 31
Thread Starter 
The more i ponder this I think i might just get a 3.5mm jack and mount the relay inside the amp, i gotta go inside and do the fan mod anyways. This would be nice and clean.
post #22 of 31
Quote:
Originally Posted by mpenton View Post

Wouldn't something like this http://www.sears.com/shc/s/p_10153_1...G2#reviewsWrap

work? Plug receiver in as main, run power amp as accessory, turn on receiver, power amp is automatically powered.

First-hand account: I tried one of those with my old receiver, and it would cycle off a lot (like every few seconds). I think the receiver did not consistently pull enough power to keep it firmly switched on. IMO, it is not suitable for this purpose.

I also have one of these smart power strips, and it works just fine. It has an adjustable trigger current, and even a low-energy Panasonic SA-XR50 receiver has no problem switching it on:
http://www.amazon.com/Smart-Strip-SC...605393&sr=8-12


Silly idea for generating a 12v trigger signal with a Pioneer VSX-1021:
* plug the receiver into a smart power strip like the one linked above
* plug a 12v "wall wart" power supply into a switched outlet on the smart power strip -- the output will be your 12v trigger signal

-Max
post #23 of 31
You can but a variety of relay boards off ebay and other sources that have one or more relays and are relatively cheap. Some are even remote controlled. Use your AVR to drive the switch in, and a small plugpack to supply the coil of the relay. $20 and an hours work at most.

Make sure the relay rating is suitable for what you want to do.
post #24 of 31
Thread Starter 
Quote:
Originally Posted by A9X-308 View Post

You can but a variety of relay boards off ebay and other sources that have one or more relays and are relatively cheap. Some are even remote controlled. Use your AVR to drive the switch in, and a small plugpack to supply the coil of the relay. $20 and an hours work at most.

Make sure the relay rating is suitable for what you want to do.

Something like this looks nice but can't find anything rated to like 20A......

http://www.ebay.com/itm/4-Channel-5V...97432603740988
post #25 of 31
Quote:
Originally Posted by NicksHitachi View Post

Something like this looks nice but can't find anything rated to like 20A......

That looks like a great board to use as a starting place. Add another low-voltage power supply and use those tiny little relays to drive a real relay that can handle some real current draw...
post #26 of 31
Thread Starter 
OK so did the trigger mod today. Works great. Spliced in after the main switch on the amp so I can still kill the power if something ever requires I shut it down manual.

Bought supplies.

3.5mm jack and Relay and through hole board:




Removed this foam not real sure why its there..... Amp fan runs much quieter and slower with it out......



Shot of relay after switch with 12v trigger current coming in on the twisted blue white pair.




Nice finished look. The way it should have come from the factory.




The relay mod works well, I did have to adjust my trigger delay for the amp to keep away the dreaded thud when all the other gear powers up but that was a simple setting in the projector.

I'll never have to flip the amp switch again unless I want to and that is worth the time it took to disassemble the rack do the mod and put it back together.

Total cost... about $10 for the 1/8" jack, relay, and board. The rest I already had but it did take about 4hrs.....
LL
LL
LL
LL
LL
post #27 of 31
The foam is to keep dust out.
post #28 of 31
Fan runs back to front, the foam keeps the dust inside the amp....
post #29 of 31
Thread Starter 
Quote:
Originally Posted by A9X-308 View Post

The foam is to keep dust out.

Yeah I've just never seen a filter on an exhaust.

These were built for other places besides my nice clean theater, none of the other gear has a filter covering the vent holes so I'm sticking with it out.
post #30 of 31
Looks like you found a great solution to automate power to your sub amp! I like the clean and neat appearance...

I would replace the foam filter, though. The fan blows from the back of the amp to the front, through the heat sink tunnel. The end of the heat sink tunnel then hits the "filter" which is really more of an air diverter. The point is for some of the airflow from the fan to blow out to the left and right sides of the chassis (where the vent holes are on the sides). This helps keeps some of the sandcast power resistors on the PCB cool.

The purpose of the "filter" is to provide some air-flow resistance, thus pushing air out the sides AND the front of the chassis. Without this resistance, the air flow will go straight out the front of the chassis and will not provide the necessary cooling for the rest of the components inside the chassis.

I would recommend reinstalling the filter piece that you removed.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: DIY Speakers and Subs
AVS › AVS Forum › Audio › DIY Speakers and Subs › DIY switched outlet