Is this school Dimmer DMX, multiplex of something else?

[J Pearce]

Most small hire cos would sort something like that out for a school if asked nicely. A box of chocolates can go a long way!

[themadhippy]

Didnt furse use there own control protacal?

[Shez]

The black desk & dimmer are indeed Furse units. They use a protocol called FMX - their proprietary analogue multiplex that's incompatible with anything else. I believe there are boxes out there that will convert to / from FMX to less archaic formats but they're not exactly common any more. The DIN socket visible just above the audio stagebox is indeed the connector that they use.

 

The central panel on the dimmer (held on with two large flat blade screws) covers the fuse panel - the number of fuse carriers behind there will tell you how many channels the dimmer has.

 

I think the "bar lights" to which you refer are cyc floods / battens. They're heavy and awkward to de-rig from the top of a ladder...

[paulears]

The bar things - are compartment battens - every 3rd or 4th connected together so they can do a 3/4 colour wash - each with probably 150W lamps per compartment.

 

They'll almost certainly be permanently wired in, and will probably contain asbestos - so not things you really want to take down yourself at all!

 

It's all very well thinking about getting DMX dimmer packs in, but:

1. Do you have any proper power sockets for them?

2. How will you get power up to the bars?

 

It means lots of rubber cable everywhere, because your sockets are hard wired to the dimmers. People are suggesting demux units - are you clear what these are?

Your dimmers need a voltage, usually 10V for full brightness - and the demux 'listens' to your DMX output and splits it into 24 separate output circuits - you seem to have 30 dimmers - so can either opt for 26 of them, or get 2 demuxes.

 

Now the bad bit.

 

I really can't see the school letting you remove the panels to gain access to the low voltage lines connected to the dimmers? Some may be wired through sockets, but unless you can get access to all the dimmer channels, it's going to be a fairly complex thing to do. Your extra dimmer idea may well be best - IF there are power sockets already fitted. If not, they can be quite expensive to have fitted. The FADERS on the control desks may well be a bit worn too, so before attempting to alter the kit, find out if it really works - so you're going to have to test everything, thoroughly and diligently.

[J Pearce]

The demux could connect to the 10v lines currently connected to the level 12 though, and at least control whatever that is controlling.

[paulears]

Agree! Trouble is it's just a real bodge - and I doubt very much the school are going to shell out for anything at all, based on the fact nobody has bothered to update the installation. We've got a 1980s/1990s install that was never that effective when they added the second version.

[Brian]

I've searched Zero88 demux on eBay but no results, could you possible give a link, I'd really appreciate it :)

Ah, sorry, the auction ended on Monday. Here it is.

[Junior8]

All the lanterns shown are Furse. Paul is right about testing I'll bet a lot of this stuff simply isn't working. My guess would be that the compartment battens and the JFRs where installed at the same time and that the Zero 88 desk is merely controlling the fresnels with the ways for the battens not being used - is the Furse desk connected at all?

[JAAMM]

The bar things - are compartment battens - every 3rd or 4th connected together so they can do a 3/4 colour wash - each with probably 150W lamps per compartment.

 

They'll almost certainly be permanently wired in, and will probably contain asbestos - so not things you really want to take down yourself at all!

 

It's all very well thinking about getting DMX dimmer packs in, but:

1. Do you have any proper power sockets for them?

2. How will you get power up to the bars?

 

It means lots of rubber cable everywhere, because your sockets are hard wired to the dimmers. People are suggesting demux units - are you clear what these are?

Your dimmers need a voltage, usually 10V for full brightness - and the demux 'listens' to your DMX output and splits it into 24 separate output circuits - you seem to have 30 dimmers - so can either opt for 26 of them, or get 2 demuxes.

 

Now the bad bit.

 

I really can't see the school letting you remove the panels to gain access to the low voltage lines connected to the dimmers? Some may be wired through sockets, but unless you can get access to all the dimmer channels, it's going to be a fairly complex thing to do. Your extra dimmer idea may well be best - IF there are power sockets already fitted. If not, they can be quite expensive to have fitted. The FADERS on the control desks may well be a bit worn too, so before attempting to alter the kit, find out if it really works - so you're going to have to test everything, thoroughly and diligently.

 

Hi,

Thanks for all the information - very interesting to an electrical nut :D

 

I'll assume until I can look that the furse used to work with the black board to control the over stage lights & the cream is for the 12 channel dimmer on the IWB over the hall.

 

I was thinking of using dimmer packs for the front of stage lights only - the lights have 15A plugs on so would have to replace them with IEC's or get/make some adapters. I am also aware of max current V x A = W ext... and how much I can put on each channel. I would have the dimmer packs put up with the lights and run a mains & DMX cable up the lights (I think one four channel would be enough for said show ATM).

 

These 'demux units' convert DMX channels into 0-10V outputs that the analogue dimmers can understand right? I understand the difference between the two (DMX - digital signals in same cable, analogue - 1 live ELV cable each for control) I guess 5V in would mean 50% intensity and 10V 100% right?

 

You would be right in assuming these are not an option, as the school would not want to spend money buying/renting them. Most of the other stuff is my own and I wouldn't want to buy one as I'd have no other use for it. As far as their concerned the lights work well enough to light the stage & that's all they want :(

 

In your opinion would it be worth buying one of theses if they would? Or would it be better to save up and have a new DMX system installed (I understand the cost would be much higher for that).

 

So the current dimmer, the 12 channel one for example will have one 10V output and 6 0-10V + ground per 8 pin din plug inputs (read in wiki) and the controls sliders lower/higher the voltage with resisters ext... to achieve this right? Just to get it straight in my head :D

 

Now above the stage I was going to suggest to the teacher to get the compartment battens (thanks for that) removed as I don't think they work anyway (I guess they will want an electrician to do this for health and safety reasons) as that would allow me to put the LED cans and scanners on their bars (weight permitting of course). However you say they may has asbestos in them, which creates a problem... Should I alert the teacher to this possibly and recommend they are removed in a safe way? I will try and get a better picture of them!

 

Thanks a million everyone :)

[JAAMM]

All the lanterns shown are Furse. Paul is right about testing I'll bet a lot of this stuff simply isn't working. My guess would be that the compartment battens and the JFRs where installed at the same time and that the Zero 88 desk is merely controlling the fresnels with the ways for the battens not being used - is the Furse desk connected at all?

 

 

No, it has a cable (I assume DIN) which is just left hanging, I know there's a DIN faceplate next to the black dimmer so there may be another in the lighting box which are connected together, I'll have a look. Most of the sliders have broken off it though so its a bit worse for ware! I don't know where the main switch is for the black furse dimmer and have never seen it on, don't really want to switch it on TBH what with its state and potential asbestos wiring in the battens!

 

I've just been reading about the furse fresnel lanterns, it says they were made until 1983, so the installation is at least around 30 years old don't you think?

 

 

I've searched Zero88 demux on eBay but no results, could you possible give a link, I'd really appreciate it :)

Ah, sorry, the auction ended on Monday. Here it is.

 

Never mind haha, would have done the job I guess but wouldn't have been able to afford it anyway!

[sguy42]

Furse were taken over by CCT Lighting, they still list a FMX /DMX converter for the wall racks, personally I don't think it would be a good investment, but it is potentiallly another option.

 

Don't rely on the discontinued date of the lanterns to date the instalation, I'm currently providing advice to a school whose 'new' hall is less than ten years old, fully equipped with new lighting when built, lanterns are mostly Furse SPKs, discontinued about 1983 and obviously sat in someones store for ~20 years. Unfortunately someone saw them coming.

[paulears]

If you can get the battens working - they provide nice even illumination and you can do colour changes. Replacing them with led cans gives you another wash tool - BUT how many will you need to have to provide a wash across the entire stage? The other thing is benefit to the school. They remove the battens, spending probably £200-300 doing it, and you put your kit in. For how long? You will leave and they will have even less.

 

Until the school decide that they need better lighting, what you're proposing is a bit flawed. You will have your equipment being used by your school. Fine if you're there. What happens when you walk in and somebody has been doing basket ball because the gym roof leaked, and your cans are all bent, or the cables have been pulled out because they were in the way? Or some outside tester the school have a contract came in, and failed your kit and chopped the plugs off because they didn't understand what they were doing. The school insurance usually specifically excludes equipment belonging to students?

 

They should really fund it themselves, and even though you are willing, is it really right to use your equipment if they don't place any importance on lighting. That's an attitude they have you need to change. Get them to fix what they have - but let's be honest. Has any of this stuff even been tested for safety? If it doesn't work, how can it have been?

 

Your understanding of how DC controls the dimmer levels is ok now. You'll find quite a few different connectors on old analogue systems, so all that matters is that they're the correct ones for the kit.

 

Please - 'sliders'. Call them faders - or if you wish to be posh, linear potentiometers (just joking - but that's what they are). 'Sliders' is a bit cringeworthy. We all know what you mean, but lighting is full of jargon, but sliders isn't one of ours. They fade lights (or sound on a mixer) - so they're faders!Before you do anything. Read a book or two by Francis Reid - then you'll have a better idea of what stage lighting is about.

[Junior8]

Cheer up James - at least after tussling with this installation the only way for your tech career in the future is up! That being said it is some time since I've seen such a mixed and archaic set-up which I'd guess has been the subject of piecemeal upgrading over the years then used once or twice a year for the odd event. The orange dymo tape labels on the Furse desk show that this did indeed control the battens at some time in the past - at a guess wired for three circuits.

 

My first idea would be to see if there was a lead that would go to the DIN plate and check if this was still working provided somebody on the staff will switch the pack on for you! If they are working - and being very basic they probably are - gelling these up will give you some nicer washes than you might expect.

 

What you need to do is to talk to the teacher responsible and jointly go through everything to see what does what - making notes as you go of what is working and what needs repair. It may be that once you do this all that's needed is a second hand analogue desk and few GS lamps. The JFRs are pretty useless but cleaning the lenses will make quite a difference even so.

 

Then for your event why not try to borrow/hire an analogue Zero 88 Sirius 24 which will give you two presets, memory and chases and will work with what you have to hand. I'd also back Paul's advice not to take your own gear anywhere near this set up. You'll make a far more significant contribution to the life of the school, going forward, by making them take a long hard look at what they already have - or don't have...

[Robin D]

Some years ago I was using one of those Furze dimmer units (18 channel) in a school. It also had a number of 'D' connectors in addition to the FMX. These were undocumented so I opened up the cabinet and checked the wiring to see that they were wired into the control with circuit. I deduced they were analogue inputs and with a bit of testing soon found the pin-out. It's a bit hazy, but I think they were the dimmers that were 0-12v control, rather than 0-10v, but that may have been a Colortran dimmer I was involved with about the same time. (I stress here that I was in my late 40's at the time so not a student!)

 

The short and the long of it, is that the OP's pack may be wired the same way with dual control. The outlets were on the side of the units, in a row near the bottom and were a pain in the butt as they had no retaining screws for the first show I did. (Soon fixed that for the next show!)

 

All this come with a big caution as its seems as though the OP may well be out of his depth (his profile shows him as a student). If at all unsure, get some skilled help in. Indeed, if he added his location, some BR members may be able to assist with a bit of 'advice'.

 

Edit: Typo plus took so long to type (diverted to another task), thread now confirms student status.

[JAAMM]

If you can get the battens working - they provide nice even illumination and you can do colour changes. Replacing them with led cans gives you another wash tool - BUT how many will you need to have to provide a wash across the entire stage? The other thing is benefit to the school. They remove the battens, spending probably £200-300 doing it, and you put your kit in. For how long? You will leave and they will have even less.

 

Until the school decide that they need better lighting, what you're proposing is a bit flawed. You will have your equipment being used by your school. Fine if you're there. What happens when you walk in and somebody has been doing basket ball because the gym roof leaked, and your cans are all bent, or the cables have been pulled out because they were in the way? Or some outside tester the school have a contract came in, and failed your kit and chopped the plugs off because they didn't understand what they were doing. The school insurance usually specifically excludes equipment belonging to students?

 

They should really fund it themselves, and even though you are willing, is it really right to use your equipment if they don't place any importance on lighting. That's an attitude they have you need to change. Get them to fix what they have - but let's be honest. Has any of this stuff even been tested for safety? If it doesn't work, how can it have been?

 

Your understanding of how DC controls the dimmer levels is ok now. You'll find quite a few different connectors on old analogue systems, so all that matters is that they're the correct ones for the kit.

 

Please - 'sliders'. Call them faders - or if you wish to be posh, linear potentiometers (just joking - but that's what they are). 'Sliders' is a bit cringeworthy. We all know what you mean, but lighting is full of jargon, but sliders isn't one of ours. They fade lights (or sound on a mixer) - so they're faders!Before you do anything. Read a book or two by Francis Reid - then you'll have a better idea of what stage lighting is about.

 

Hi, I've had a word with the teacher and he says the battens have never been used as long all the time he has been there (10 years) and does not know even how to turn them on or if they work. He therefore doesn't mind having them taken down as they are never used anyway. Allot of building work is taking place over the holiday so he don't think it'll be a massive problem to get them removed (I've told him about possible asbestos).

 

Once they are gone, this leaves me 3 over stage bars to put temporary lights on, I though something like this.

http://tomlinson-net.org/james/school-lights/Q%20Factor.jpg

 

I think that should provide enough illumination over the stage (better than what they usually have which is nothing!) Any thoughts? I'm happy to be criticized :)

 

As for the par can on the front of the stage, they are normally there, but I''m not sure whether they are needed what with the new above stage lights? I'm a bit worried about lighting the performers like features and the shadow they would cause.

 

Having watch a video of last years show, I've realized front of stage lighting will be very important as just about all the acts some past the proscenium arch at some point, making the above stage lighting not enough.

This is the layout of the lighting above the hall, aiming at the stage:

http://tomlinson-net.org/james/school-lights/Stage%20Front%20Lights.jpg

None of them have coloured filters on ATM, but all work.

 

I understand what your saying about my stuff, it has all been PAT tested though so they seem happy to use it. I get what your saying about them not spending money, but I don't get many chances to do a light show like this, and I really enjoy it (its not 'till Christmas and I'm planning now!) so I don't mind doing it myself & with the help of a friend. I also may like to use in a university portfolio.

 

I understand that my designs are not ideal or the best, but I'm working with what I've got, as new stuff or hiring is not really possible. Not that I don't want to do a good job, I do want it to look really good, but as far as they'll see, anything I do will be an improvement...

 

I have an idea about the 12 channel dimmer, I'll post back when I've done some plans & thanks for the 'faders' info, I like new words :)

Thanks!& Thanks everyone else for you input :D

 

PS - sorry about the paint drawn designs, did them in a hurry!

 

PSS - The stage last year, there is another par can you can't see, the 'present' is hiding the monitor with the song lyrics on & The cans were just plugged in and left on all throughout.

http://tomlinson-net.org/james/school-lights/2010%20Stage.JPG