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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Lighting Forum => Topic started by: Goerge Thomas on February 19, 2016, 03:00:28 PM

Title: How to control fans on stage with dmx
Post by: Goerge Thomas on February 19, 2016, 03:00:28 PM

Hello all,

So I have a simple problem, needing maybe a complex solution.

I have a permanent outdoor stage with side, back and roof structure. I use a lot of haze in the summer and fog and the heat makes it rise and not spread enough without fans. In the past I have used 2 industrial fans pointed down on truss 25 feet up to move the haze and fog around the help accentuate the lights and evenly mix the fog. This has worked well. I generally just have to plug the fans in before the show as they are permanently mounted on the truss. It's not elegant. I would like to control the fans on and off via DMX so I can decide when they come on and off with my light show and have a setup that all talks and is more elegant.

I've read so many threads saying I can't just plug the two fans into a dmx dimmer pack and set it to 100% or 0% on or off. The fans draw 8 amps each and are not variable speed.

Any thoughts? I know they make dmx controlled fans but I'd like to use what I have. Many people have told me that you CAN use a dimmer pack but dimming the pack to control fan speed is not advised.

Title: Re: How to control fans on stage with dmx
Post by: John L Nobile on February 19, 2016, 03:36:01 PM

I used to use this to control a fan and a non dmx hazer. Worked well as I could control both individually.

http://www.chauvetlighting.com/dmx-4.html

Title: Re: How to control fans on stage with dmx
Post by: Goerge Thomas on February 19, 2016, 03:51:48 PM

Quote from: John L Nobile on February 19, 2016, 03:36:01 PM

I used to use this to control a fan and a non dmx hazer. Worked well as I could control both individually.

http://www.chauvetlighting.com/dmx-4.html

That is what I have. about 6 of them not in use since I switched to LED. It worked without issue? What about dimming the channel to lower the fan speed?

Title: Re: How to control fans on stage with dmx
Post by: John L Nobile on February 19, 2016, 04:15:26 PM

Never tried to dim them. I just used them as a remote on/off switch. Never had a problem with it though I stopped using it a few years ago when we got a DMX hazer.

Title: Re: How to control fans on stage with dmx
Post by: Mark Cadwallader on February 19, 2016, 04:20:10 PM

Quote from: John L Nobile on February 19, 2016, 03:36:01 PM

I used to use this to control a fan and a non dmx hazer. Worked well as I could control both individually.

http://www.chauvetlighting.com/dmx-4.html

I don't think those units will allow an 8A load on a single dimmer. (5A max per duplex receptical, IRRC.)

Title: Re: How to control fans on stage with dmx
Post by: veditor78 on February 19, 2016, 07:40:41 PM

These would require some DIY for power supply and boxes, but they are relatively inexpensive and would do what you want.

http://www.apogeekits.com/dmx_controlled_relay_vm138.htm (http://www.apogeekits.com/dmx_controlled_relay_vm138.htm)

There are a few options on this site as well.

http://www.bpesolutions.com/dmxproduct.html#anchor285759 (http://www.bpesolutions.com/dmxproduct.html#anchor285759)

Then there is always Doug Fleenor. Ready to run but more expensive.

http://www.dfd.com/1r20.html (http://www.dfd.com/1r20.html)

Title: Re: How to control fans on stage with dmx
Post by: David Buckley on February 20, 2016, 01:56:09 AM

What you need is a DMX relay.  These come in two types, dimmers that go 0% and 100% with nothing in between, and devices that use actual relays.  The real relay type are good fore this sort of application.

If you want to build your own, the guts of the job can be bought from Northlight Systems (http://northlightdmx.com/dmxtorelay.htm).