+12v triggers

[Peppy]

Hi, everyone, one more quick question (and probaly very easy one) for you guys. What When and how do I use the +12v triggers on my 3805 ?

Like I am looking to add a fan to increase the ventilation on my equipement, not that I expect having any "hot" problem, but I don't think that too much ventilation is ever bad. So, does that 12 volt triggers can run the fan ?

 

[perato]

If you are using a fan from a computer, it will not work. The 12-volt trigger I have in my Onkyo receiver emits a 12-volt pulse, not a constant DC 12 volts. Most 12-volt triggers work this way. 12-volt triggers are designed to be used as switches. For example, the 12-volt trigger can be connected to an amplifier to turn the amplifier on and off. I use the 12-volt trigger on my receiver to switch my speakers between monopole and dipole mode.

 

[howie85]

How many amps you think could be switched by one 12v output?

 

[BMXTRIX]

That's weird that it would be a momentary pulse on any device. Usually 12 volt triggers are constant on to let a device know that they should be, and REMAIN on. When 12 volts is removed, the device IMMEDIATELY turns off.

12 volts, at a very, VERY low power rating. It is not designed to power external devices, but to trigger low voltage relays that turn external low voltage devices on and off.

If you want to power an external device with more fans, then get a fan that uses an external power supply and can be triggered using the 12 volts coming out of your receiver. It sounds a little rougher to get to the final point you want to, but it keeps your cooling system on a separate power supply, as it should be, from your A/V receiver.

 

[m1abrams]

One way you could build your own Fan with 12V trigger is to put a SPST relay on the fan, and use the +12V trigger to connect to the coil of the relay. This is basically what is used in amps that have remote switches that are designed to work with the +12V trigger.

Whatever you do, do NOT attempt to power the fan from the +12V trigger.

 

[perato]

I was wrong. The 12-volt trigger in my receiver is not a pulse. I checked it by activating the trigger then disconnecting the wire from the receiver. The trigger deactivated. When I reconnected the wire to the receiver, the trigger reactivated. Before I installed the 12-volt trigger, I asked the dealer I bought the speakers from if the 12-volt trigger was a pulse or a constant current and he said it was a pulse. I hope I have not reduced the life of my speakers.

 

[BMXTRIX]

No issues at all, there is just a really cheap transformer in there that runs the 12v triggers. Just no amperage at all behind it. You can try to run your fans, and pretty much nothing will happen since there is no real power behind the 12 volts.

As I said, it is used for relay contact points - like the way a security system works. A tiny bit of 12 volt power on a low voltage relay detector can trigger a screen to drop, amplifiers to turn on, or any number of other events. But, the actual power that turns those items on or drops the screen comes from somewhere else.

 

[HowY]

Thought about this:

I use the "switched" power outlet on my rcv'r

get a BRICK 12v rated close to the fan requirements.

I use this method to power 3 20mm cpu fans that
run through a rheo for setting the speed.

no humm or line noise and cool (er) Components