DMX Power board

[baker]

Hey guys,

Im looking to build a dmx powerboard to enable more fixtures to be patched then the number of dimmers i have.

The lights wouldnt be used at the same time and it would be easier to have the desk "flip" the switches on the power board then climbing through dimmer land.


Any ideas where i can find a plan for such a device?

[tk2k]

Hey guys,

Im looking to build a dmx powerboard to enable more fixtures to be patched then the number of dimmers i have.

The lights wouldnt be used at the same time and it would be easier to have the desk "flip" the switches on the power board then climbing through dimmer land.


Any ideas where i can find a plan for such a device?

I think I speak for everyone when we say we have absolutely no idea what you mean by a 'dmx powerboard' and neither does google.
The number of 'fixtures' has nothing to do with the number of dimmers, your lighting console will have a fixed number of channels it can support, which is probably way above the number of physical dimmers you have.

Are you trying to get more physical DMX sockets? Do you want an A/B switches so your dmx feed goes one place or another?

[rphilip]

I think he's looking for DMX controled relays so that one dimmer output can be switched beween 2 different fixtures for independant but (mutually exclusive control).

Philip

[gafftaper]

Sorry Baker, I never heard of such a thing and I question it's reliability/safety for use during a show if you build it yourself.

[gafftapegreenia]

If you have the extra DMX channels on your board to be able to control relays, why not just buy some cheap dimmer packs/rent some dimmer packs.

If you are trying to increase your DMX channel count coming out of the board, well, I don't really know a way to do that.

[tk2k]

I think he's looking for DMX controled relays so that one dimmer output can be switched beween 2 different fixtures for independant but (mutually exclusive control).

Philip

OOOH you mean a dimmer doubler? Do you have ETC racks? if so this baby is your ticket, but it's not inexpensive
http://www.etcconnect.com/docs/docs_...Doubler_vF.pdf

[Chris15]

He's here in Aus.
Chances are fairly slim of him having ETC racks...

[tk2k]

Oh, really? What do you guys use down there?

[Footer]

Oh, really? What do you guys use down there?

Strand and Jands. Yes, I know, the idea of another lighting manufacture is crazy. I am glad ETC came along and rescued us from saltwater dimmers. :banghead:

Sent from my Galaxy Nexus using Tapatalk 2

[gcpsoundlight]

It could be done but I wouldn't want to. If there is no chance of having the 2 fixtures on at the same time, you could rent another rack and a 3 phase splitter.

[Chris15]

Now that I have the time to reply more verbosely...

Strand racks in use tend to be old analog ones.
Most installs in the last 10 - 15 years are using either Jands or LSC.
In BIG venues, sure you can find the rack and module form factor you guys Stateside are accustomed to, but in small venues, schools etc. it will generally be 3RU 12 channels dimmers or the wallmount version thereof.

As to the OP's proposed contraption...
First off what have you got at the moment?
Next, what are you willing to spend?
How many channels do you want A/B switching for?
You did only want A/B yeah, you aren't picturing a 4 way switching arrangement or something are you?
What COMPETENT labour do you have available?

Is such a device possible, sure.
Will it be cost effective? Completely different question...
As a minimum you will be looking at a supply lead and plug, 2 outlets and an properly rated (so >10A per pole) DPDT relay and an enclosure, and that's before you add a power supply and all the other low voltage electronics to make the DMX thing happen...

3 phase double adapters MUST be considered as a tool only to be use by competent individuals. There is a very real chance of fire if you don't know what you are doing and use one...
I'm sorry to put it bluntly, but MOST high school students don't have the skills to be deemed competent.

[tk2k]

Strand and Jands. Yes, I know, the idea of another lighting manufacture is crazy. I am glad ETC came along and rescued us from saltwater dimmers. :banghead:

Sent from my Galaxy Nexus using Tapatalk 2

I don't really understand your... whatever that was..... it's a completely legitimate question

[JD]

I don't really understand your... whatever that was..... it's a completely legitimate question

ETC is almost a pseudo-monopoly here in the states. Not that there are not other manufacturers, just that sometimes it feels like they are the only one! As such, there is a bit of humor in thinking of a country without ETC! ... OMG!

I think Kyle intended that as a joke about ETC, not the question

[kicknargel]

I must admit, I think the idea of what is essentially a DMX-controlled patch bay is pretty cool. If your available dimmers and available power are limited, it could be a handy thing. Plus, I have a soft spot for unique, kuldgey solutions. That said, there's no way it should be attempted by other than a licensed electrician and probably shouldn't be implemented without a UL listing. As mentioned, probably cheaper and safer to add a couple DJ-style shoebox dimmers.

[tdeater]

I wounder if something like this might work: Northlight Systems DMX512 decoder, 0-10 VDC output. Use it to drive a DPDT relay rated for the voltage and amperage you need.

[n1ist]

The 0-10v board doesn't have enough current output to drive relays. Northlight Systems DMX512 to Relay circuit board, includes relays and address switch. is a better choice. Tou would still need external DPDT relays to switch your loads, in a grounded metal enclosure, with proper wiring techniques. Certainly doable, but it still would be cheaper to go with shoebox dimmers if the additional fixtures are low-enough power.
/mike

[Chris15]

The doctor makes a device that would work nicely...
Doug Fleenor Design - 96 Ch. Open Collector

[TimMiller]

Can you just 2fer some fixtures up to gain you some more channels? Personally, if I run out of dimmers I will bring in a little rack to give me some more.

[DavidNorth]

Use it to drive a DPDT relay rated for the voltage and amperage you need.

Do be careful here. Relays have different ratings for resistive versus tungsten loads and tungsten current ratings are always much lower. Doing a live transfer under load with an under-rated relay could cause a variety of problems. FYI, fully rated tungsten contactors are not cheap.

FYI,
David

[Chris15]

And different ratings again for inductive loads...

[baker]

Im a horrible person for posting and not following my thread for a year :S sorry.

After reading through all of your posts, i think i have an idea of a good prototype that would be same a suitable for the job.

I just need to design a safety device to prevent switching while under load.

Im got a lot of down time in venue this week, with nothing to do but watch dimmers for 12 hours a day...