Horizon Dimmers

[acooper]

Hi guys, this is probably a stupid question but hoping someone on here will have an idea. In our school Drama department we have too very ancient Horizon Dimmer units both 18 channel.

We have just purchase an updated controller, cabling etc but unfortunately when connectIng both units to a splitter then into the desk both Dimmer units are running on the same DMX address ie both channel 1 on the dimmer units are running of DMX channel 1 (its worth saying we have a similar setup in our main hall with the same dimmer units but one unit is DMX channel 1-24 and the other is 25 - 40 etc). Does any one have any thoughts on how to change one of the dimmer units to run from a different DMX address?

 

Cheers - sorry if this is an obvious question but I would be great full for some help if possible.

[DrV]

There will be some configuration switches somewhere either on the front or rear panel of the units or possibly inside them. You will need to set them to 18 (or perhaps 17) on the second dimmer. If you find them but can't work out what to do then put a photo of them on a website and post a link to it here.

Do they have a numeric display on them of any sort?

Dave

Edited July 20, 2018 by DrV

[acooper]

Hi there Dave,

 

unfortunately there is no display on the unit, I have opened it up hoping to see a DIP switch or something like that to select the starting address but alas there is nothing that I recognise.

[Brian]

Post some photos of the PCB. You'll need to host them somewhere else like photobucket and put the link here.

[Paul O]

If the dimmers are ancient, they are more likely to be analogue rather than DMX. Is there a demux in the installation somewhere?

[Hilary Watts]

see this thread. ...and in particular note Brian's post concerning the demux in the dimmer rack.

 

It doesn't actually answer the question but it looks as if things aren't exactly straightforward!

[acooper]

Hi guys here are the pics of the unit.

 

And here.

 

And here.

[DrV]

Crumbs... that brings back memories - double sided non pth boards and having to solder all those little link wires through the board. But that was for PDP11 interfaces in the late 70s - I digress.

What we need is really clear pics of the left hand end of each board - clear enough to read chip numbers if possible.

What are the three components in the lower left corner of the 3 triac boards? And if they are little toggle switches what are their positions?

 

No - just spotted the addresses! There is a row of 6 pin pairs just above the ribbon cable on each triac board and they are currently set to 1 2 and 3 respectively. If you move those to 4 5 and 6 I bet you'll find that works

Edited July 20, 2018 by DrV

[Brian]

...its worth saying we have a similar setup in our main hall with the same dimmer units but one unit is DMX channel 1-24 and the other is 25 - 40 etc). Does any one have any thoughts on how to change one of the dimmer units to run from a different DMX address?

 

Might be worth looking at the unit which does work.

[acooper]

Cheers guys I will definitely have a look at those pins, plus I'll open up the working units and have a gander. I'm away from work for a week but I'll post how I get on. Thank you all again. Edited July 20, 2018 by acooper

[MarkE]

Hi! The school where we perform has a Horizon rack as described. Unfortunately during lockdown the dimmers either drifted or were tweaked so the pre-heat was too high, and it was impossible to get a blackout (you got a red glow instead). I asked the school to have this corrected when their tame PAT tester came in, but unfortunately he's now set it totally wrong, and some dimmers don't come on until 50 or 60%. Although I've built my own dimmers in the past, and am fairly familiar with what's going on, not surprisingly I'm not allowed inside the box. However, I'd like to know as much as possible before trying to get the man back to fix it (hopefully while I'm there!). So: (a) if acooper is still around and sees this, would it be possible for you to post or put in, say, dropbox, a higher resolution image of the internals? (b) does anyone have any technical information on the Horizon, or know where I might find it (Googling only yielded this page); and (c) failing that, does anyone know what the trimming entails (I'm kind of assuming there's either one pot or two which control a base level and possibly tweak the top end so you can get maximum brightness).

 

Edited September 20, 2022 by MarkE
Text got put in twice

[kgallen]

Not Horizon, but if it helps, see here where Keith describes the method to set preheat on a Betapack2 - the method on the Horizon dimmers should be similar:

https://www.zero88.com/forum/topic/3748-betapack-2/#comment-19272

[MarkE]

Hi! Thanks - from the reply it suggests the pots have simply been taken down to 0, and that gives the behaviour I'm seeing. Really helpful! Cheers mark.