Dimmer Pack on a Dimmer

Amiers

Renting to Corporate One Fixture at a Time.
Joined
May 28, 2009
Location
Phoenix, Az
No, but you can TIL you cant. if you need the extra circuits and no other options do so at your own risk.
 
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Amiers

Renting to Corporate One Fixture at a Time.
Joined
May 28, 2009
Location
Phoenix, Az
You are being pretty vague. You got some details. We got plenty of work around.
 
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Lynnchesque

Active Member
Joined
Feb 28, 2019
Location
Fresno, CA
Basically, It's an old space with dilapidated gear, so I am avoiding using any of it. But that comes with limited power distribution, 6 60amp relays. I may have to resort to snaking AC throughout the building, ha.
Unfortunately I don't have any more details, I am not loading in to the space for a few weeks.
 

seanandkate

Well-Known Member
Fight Leukemia
Joined
Aug 29, 2008
Location
Stouffville, Ontario
What I need is a converter from DMX to whatever communication standard was used in the 1970s
Options for DMX to AMX (common in the 70s) converters abound. I gather there is no existing lighting board or you want to use something more recent with a little less dust on it?
 
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Lynnchesque

Active Member
Joined
Feb 28, 2019
Location
Fresno, CA
There is an existing lighting board, a massive 2 scene preset + master control (2-3 person operated) and likely older than I am. The go-to strategy for anyone in the building is to completely avoid using it, as it may be unreliable; and fewer and fewer circuits work every time.
I guess I shouldn't be surprised that there are indeed options to adapt... but I'm not surprised that no one in the venue has taken the time to purchase such a thing. I believe the thinking has been that this system was just about to be scrapped, all the way back to the first time I encountered it, oh say 15 years ago. The building itself came very close to being condemned recently, so it's kind of a miracle we can get in there at all.
 

RonHebbard

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Premium Member
Joined
Jun 12, 2004
Location
Waterdown, ON, CA
There is an existing lighting board, a massive 2 scene preset + master control (2-3 person operated) and likely older than I am. The go-to strategy for anyone in the building is to completely avoid using it, as it may be unreliable; and fewer and fewer circuits work every time.
I guess I shouldn't be surprised that there are indeed options to adapt... but I'm not surprised that no one in the venue has taken the time to purchase such a thing. I believe the thinking has been that this system was just about to be scrapped, all the way back to the first time I encountered it, oh say 15 years ago. The building itself came very close to being condemned recently, so it's kind of a miracle we can get in there at all.
@Lynnchesque Any chance of photos?
Toodleoo!
Ron Hebbard
 
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JD

Well-Known Member
Joined
Jan 1, 2005
Location
North Wales PA
Most common formats in the 1970's were analog: Many were 0 - 10 Vdc although EDI was 2 - 7.6 Vdc (Those rebels!)
Running a dimmer off of another dimmer is almost always a bad idea. Some vendors supplied true relay or switch modules, but age might prevent you from finding any.
 

Ben Stiegler

Well-Known Member
Joined
Aug 3, 2017
Location
Sf Bay Area
I’d load in an extra fire extinguisher and a loud BYO smoke alarm if you are gonna try the cascaded approach... spidey sense screaming “danger, Will Robinson” in the background
 
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Lynnchesque

Active Member
Joined
Feb 28, 2019
Location
Fresno, CA
So I'd be curious to know why exactly this is so dangerous; I've got a pretty good plug-n-play understanding of theater tech, it's the in-depth electrical engineering stuff that I don't know a whole lot about. My guess was, like any moving light, the electronics in the dimmer pack could be damaged by the dimmed power- so not a great idea. But it seems like something else is afoot? Interacting sine waves that cause the thing to explode? Magnets? An affront to the gods?
 

Mac Hosehead

Well-Known Member
Joined
Sep 10, 2014
Location
Shark Tank
Powering electronics from a dimmer output can cause item to overheat. Overheating can cause release of "magic smoke" that keeps everything operating.

Your description of the console resembles the one from my college days. It took more than one operator to work a show. It was a Century Strand system and had a 0 to -12 volt control of the dimmers.
 
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Ben Stiegler

Well-Known Member
Joined
Aug 3, 2017
Location
Sf Bay Area
alt exploration - your final dimmer's power supply expects nice, clean 120V 60 hz sine waves without phase phiddling or leading/lagging edge chopping. Sometimes you can cheat it a little bit - like running it on a $1K Home Depot generator at a spontaneous rave ... but it really doesn't like adjustments to that sine wave. Cheap generators (and yes, dimmer outputs even when up to 100% on your control system) aren't always putting out that pure sine wave. Lamps don't care. Downstream power supplies often do. Even if you don't let the magic smoke out right away, it can cause component vibration, overheating, and other precursors of the dreaded EFS - Early Failure Syndrome.

If you want to see for real what's coming out of your dimmer, see if you can lay hands on an oscilloscope, and monitor the dimmer waveform output first with a lamp load, and then with (if you dare) your intended load. Stare and compare - see what you learn. That's if you don't feel comfortable taking all this sage advice at face value.

Someday I'll tell you about the very major release of magic smoke I caused which (according to bystanders) left me counting my fingers as the smoke cleared. That was a day to remember, but not to repeat.
 
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