Stupid question(s) regarding 12V Trigger

[Fincave]

Hope I can explain this in such a way that it makes sense. I have recently bought a power amp for my mains. My problem is that it dos not have a remote or a remote sensor and so it needs to be switched on manually. I am using a Harmony remote to control all my gear and switch on different components for different activities and it would be great to be able to switch on the amp at the same time with one button press. The amp does have two 12v trigger inputs but my receiver (Yamaha RX-V 640) does not have a trigger output which does not help. I have a Onkyo cd player that does not have a trigger but it does have the RI remote control which iirc is the same that Kenwood use on some of their gear. I previously owned a Kenwood receiver and cd and using the RI connection it would power on the cd when powering on the amp. Would this work as a 12v trigger for my amp, surely it can't be this simple? It is not a big problem having to get up and turn the amp on or off, it would just be convenient to not have to get up. Any suggestions are most welcome.

[Wayne A. Pflughaupt]

There are a couple of ways you can deal with this. The cheapest is to get an AC adapter rated for 12 volts (actually, anything in that ballpark will probably work) and plug it into one of the Yamaha's switched outlets. Then it becomes your 12v trigger.

A more elegant option, but a bit more expensive, is to get something like the Panamax 1000, which essentially is a switchable power strip that looks like a system component. It has a sensing line that plugs into the receiver's switched outlet that activates all the 1000's outlets when the receiver is powered, kinda like they do with car stereo gear. The 1000 has a seperate heavy-duty plug going to the wall, so the load of the equipment isn't put upon your receiver.

A similar unit is a 90s vintage Adcom ACE-515, which features delayed turn on for the amplifier.

Regards,
Wayne

[Sonnie]

I was gonna mention the Panamax... which I use the 5100, maybe more than you need and want to spend. I use it and the same Adcom ACE-515 that Wayne is using. I got a lot of stuff plugged up that I want operationg remotely, not to mention some sort of protection other than my whole house protection.

Wayne's idea about the 12v adapter is something simple and cheap I haven't thunk of.

[Fincave]

Thank you for the replies! Not sure about the availabilty of the Panamax in Finland but AC adaptors are readily available so will pick one up in the near future. Thanks again!

[Fincave]

Ok, purchased an AC adaptor and it works! I however have a few more questions due to my healthy respect (read paranoia) towards electricity. Translating loosely from the Finnish instructions : ' ensure that the device being connected does not require more than 300mA. Check the polarity, the most common being the negative ground. This adaptor is not regulated (stabilized). When the load is below 300mA the current produced is higher than that shown on the selector. If the connected device requires considerably less than 300mA measure the produced current and use a smaller/lesser setting' My power amp has a really useless manual with basically no specs given, nor does looking at the back panel yield any more info, how would I know if the amp requires more or less than 300mA, does it really matter for my use? Should I turn the selector to a lower setting that still works the trigger, available options are 3, 4.5, 6, 7.5, 9 and 12 the current setting. I am more than very wary when it comes to electricity hence the questions that may appear trivial!

[brucek]

how would I know if the amp requires more or less than 300mA, does it really matter for my use? Should I turn the selector to a lower setting that still works the trigger, available options are 3, 4.5, 6, 7.5, 9 and 12 the current setting.

Most cheap plug in power supplies don't incorporate any voltage regulation. A voltage regulator is designed to maintain a constant voltage output in a power supply irregardless of the load resistance (current requirements) of the device it sources.

Your power supply has an selectable voltage output switch from 3 to 12 volts. It has the ability of supplying a maximum of 300ma current at any of the settings. Since it has no regulator, the voltage value selected will not closely maintain the indicated value on the switch. When 12 volts is selected, the output could easily be 13 volts with no load. Usually a fairly small load though, will bring the voltage down in line with the value you've selected.

If your amplifier states the trigger input is 12 volts, select that and you'll be fine. I can assure you that the amps trigger input does not draw more than 300ma.

brucek

[Wayne A. Pflughaupt]

EDIT - brucek beat me to the punch...

Fincave,

The mA rating refers to current or amperage (300 mA is bit more than 1/4 amp). The “available options” are voltage settings. No matter what voltage setting you use, the rated amperage stays the same. In other words, it will put out 300 mA at 3 volts as well as at 12 volts. Make sense?

Here’s what the warning is trying to say: If you’re using a device with only a small current demand, the adapter will put out more voltage than the setting you’re using. In other words, if you have it set to 9 volts, it might actually be putting out 12 volts or even higher. Conversely, if you’re using a device that pulls the full 300 mA, then it will “drag down” actually voltage to be lower than the setting you’ve selected – maybe 6 volts instead of 9 volts.

Not to worry – DC devices are generally forgiving of “incorrect” operating voltages. For instance, if you’ve ever had a near-dead battery in your car, you might have noticed that the radio will still come on and play. I’ve fed car stereos 20 volts on the bench with a DC power supply, and it didn’t care a bit.

Back to your system, if the amp required more than 300 mA, it wouldn’t trigger on at all with this adapter. Basically, the amp is only looking for a voltage signal for turn-on, so it requires virtually no amperage. Since the current demand is low, if you set the adapter to 12 volts, it’s probably putting out at least 14-15 volts, maybe even more – not untypical. It’s not a problem, but feel free to turn down voltage setting if it worries you. Nine volts should be closer to an actual 12, and the trigger will probably even work with a 6-volt setting.

By the way, you can use a voltmeter to see what the adapter is putting out on each setting with no load.

Regards,
Wayne

[Fincave]

Thank you both Wayne and brucek! I was partly baffled by the 300mA warning and I suppose I should have been able to work out that 300mA is just less than a third of an amp, need to put my thinking cap on every now and again. It works, even when set on 6v and I do not have to worry about leaving it plugged into my receiver. A big thank you again!!!

[MdntTrain]

Hi. I have a Panamax 1000+ that has some of its outlets being triggered by an AC line input. My current Rotel surround processor pre also has a switched AC outlet.

Here's the problem: I'm wanting to change to a newer Rotel that only has 12v trigger -- no switched AC socket. Sigh. I still want to use my Panamax without "upgrading" that too. As this must be a common enough problem, does anyone know of a simple black box that has a 12v input and a switching AC socket?

Thank you very much,
~ J