DMX isolator?

leistico

Member
Hi there...

Just got through with a rather interesting problem in my theatre (I didn't have anything to do with it--apparently it happened whilst I was down with a sprained ankle and I've been hearing all about it and doing damage control)

We had a bad storm around these parts a few weeks ago, and our power went out and then came back a few minutes later. Our system (Express 24/48, 7 Leprecon 6-dimmer pipe-mount packs) took a hit when the power reestablished. Apparently, a faulty dimmer pack managed to send some sort of feedback through the DMX cable, took out two other dimmer packs and one whole universe on our (close to brand new) board.

$150 later, our board's back to 100% again. The three wonky dimmer packs are on their way to Michigan (!? -- not my doing, someone else who's been taking care of things in my absence) to be repaired.

What I'm wondering is, is there some sort of opto-isolator for DMX? My Google-fu is weak, as I haven't found anything like that out there (yet). I'd like some sort of component to be placed inline between the board and the first dimmer pack on the chain. I'd heard (somewhere?) that there exists optical isolators that work in such a way as there is no direct electrical connection between the board and the dimmers, in essence the equivalent of an isolation transformer in an audio circuit or a breaker in a power circuit. Resettable (preferred) or not, I'd like something relatively inexpensive that can isolate the system and prevent things like this in the future. It's a whole lot easier to patch around a broken cheap not-totally-necessary component than it is to drag our precious new system down out of the booth and hope and pray it's something relatively inexpensive to be fixed in short order.

Failing the existence of such an optical isolator, perhaps a cheap DMX splitter /repeater of some sort? Anyone else have anything like this in their systems? I'd love to know or get some feedback on the notion.

Thanks.

sean
 
You are looking for your basic opto isolator. If you want to simply protect your console a single isolator will work just fine, if you want to protect each pack (might be more trouble then its worth) you can get a 1 in multiple out splitter and home run each dmx run to the isolator. Both are availibe here and are very high quality pieces of gear. http://www.dfd.com/opto.html

Also, many consoles and dimmers inputs/outputs are allready opto-isolated. Most ETC racks are this way, but when you get into the cheaper gear this tends to get pulled. Many consoles also have this. Something to look into next time you are in the market for new gear.
 
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Thank you for your recommendations. Now I just need to find a place in town that would have one of those puppies or figure out how I can order one.
One of these months, I'll have to include some photos here of the space I'm working with (my "theatre") so that everyone can get some good giggles...
...picture a 45 x 75 foot room, slanted ceiling peaking at 20 feet in the middle (think church sanctuary), 30-inch elevated stage, and hang pipes that're about 10 feet off the level of the deck, slanted down from CS to SL/SR at a 15 degree angle, at 10, 30 and 50 feet back from the proscenium.
Yeah, it's that screwy lol
 
Thank you for your recommendations. Now I just need to find a place in town that would have one of those puppies or figure out how I can order one.
One of these months, I'll have to include some photos here of the space I'm working with (my "theatre") so that everyone can get some good giggles...
...picture a 45 x 75 foot room, slanted ceiling peaking at 20 feet in the middle (think church sanctuary), 30-inch elevated stage, and hang pipes that're about 10 feet off the level of the deck, slanted down from CS to SL/SR at a 15 degree angle, at 10, 30 and 50 feet back from the proscenium.
Yeah, it's that screwy lol

Call Production advantage or BMI supply.
 

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