[Michael Bishop]

I'm attempting to use the 12V trigger on the Sony VPL-VW60 (Black Pearl) projector to turn on an auxilliary fan in my projector case. I've run a 1/8" mono audio jack to the 12V input on a Russound ACT-1 switched AC outlet. My fan is then plugged into the switched AC socket on the ACT-1. The idea is that when the projector is turned on, the ACT-1 will switch on - and send power to my fan.


Unfortunately, it does not work. The only conclusion I can come to is 1) The Sony trigger is not providing enough current to trip the relay in the ACT-1 - or 2) the ACT-1 unit is somehow defective. I suspect it's number 1.


Any ideas?

 

[Michael Bishop]

I just confirmed that my Russound ACT-1 switched outlet is working properly if I apply a 12V DC 100 mA current as the input trigger. So this means that the likely issue is that the 12V trigger current level coming from the VPL-VW60 projector is well-below the threshold for tripping the relay in the ACT-1 switch. I have no way of adjusting my test DC power supply - so I don't know what the lower current threshold is for tripping the relay - but apparently the Sony Projector is below that threshold.


Oh well - and I thought this was going to be an easy little project.

 

[usualsuspects]

Sony projectors are infamous for weak 12v triggers - don't expect to be able sink more than a few milliamps from them (4.7KOhm output impedance). Typical solution for this problem is to use a Niles Audio MSU250 or similar intermediary device.

 

[mark haflich]

The Niles device has a trigger in jack that say allows 5 to 16 volts or so at low to normal trigger milliamps in amperage in and a trigger out which gives 12v out at a couple of hundred milliamps in. Works like a champ.

 

[Michael Bishop]

Thanks for the replies. It looks like the Niles MSU250 is the way to go on this.


Question: Does the 12V trigger output from the Niles provide sufficient current to power a single 4" DC fan? I'd like to do this if possible - otherwise I'd have to run the Niles trigger output into another relay to power the fan - which would be possible - but I'd rather avoid having 2 pieces of equipment to power one little DC fan.

 

[usualsuspects]

The Niles 12v out is at 200ma, so if your fan is 200ma or less, you are fine. If you need another relay, I would skip the niles and look for something else (just me). There are all kinds sensor based switches out there - or - just a thermostatically controlled fan.

 

[Jason Turk]

I agree the Sony is the culprit. In fact some of the screen companies have specific triggers for Sony projectors due to the fact that they cannot output a real 12v.