Color Scroller Power Supplies

Les

Well-Known Member
Hey guys. So, I picked up a few of these Chroma Q scrollers from a university surplus auction. From what I have read, they're basically "the original" Chroma Q scroller. Of course they did not come with a power supply, so I wanted to get some input on what PSU's out there might be compatible. I only paid like $10 each for these, so it's more of a curiosity thing. If I get them working, great. They'd be fun to use on the '80s musical I'm working on this spring.

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model number would help or a serial number. Only to gauge the age would help immensely
 
model number would help or a serial number. Only to gauge the age would help immensely

Unfortunately there are no other markings on the unit other than the DIP switch chart shown. There are three LEDs on the bottom of the unit for Power, Data, and Level. Further research shows that they might be MK1's. Based on that assumption, I'm guessing these are 24v scrollers and should work with any 24v PSU.

Now, to figure out the power consumption. I've never used scrollers, but Chroma Q lists the MK1 as consuming 1PU (Power Unit). Still haven't figured out the exact specs of what Chroma Q considers a Power Unit. For example, the Rosco PSU 50 is at a great price-point, but how many scrollers (or PU's) would it accommodate? I have 6 of the scrollers but will likely only use 4.

Rosco PSU 50:
http://www.premier-lighting.com/shop/product4216.html

Chroma Q "Original":
http://www.chroma-q.com/products/discontinued/original-colour-changer-specification.asp

Chroma Q PS08 spec sheet:
http://www.stagelightingstore.com/core/media/media.nl/id.59261/c.689066/.f?h=238f72946772aa9c79fc
It apparently supplies 8 PU's @ 130w(?). So 130/8=16.25w. Would that be my power consumption per scroller?
 
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Looks like the PS08 is the winner.
 
Looks like the PS08 is the winner.

In a perfect world, yes ;). Truthfully though, I'm not going to spend $600 on a PSU when I'm not sure that the scrollers even work. I might go with the small Rosco unit to at least test them, or find what other PSUs are compatible (from various mfr's) so I have more options on the used market.
 
I wouldn't buy one either. I'm sure you could find one to rent around and give it a test with that. Tbh if they do work though I would stick with like products and not mix and match.
 
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It apparently supplies 8 PU's @ 130w(?). So 130/8=16.25w. Would that be my power consumption per scroller?
Physics dictates that its output power cannot be more than input. Based on the specifications, it consumes 144W @ 120V or 120W @ 240V, so 1 PU must not be more than 15W. The loss from converting from AC to DC means the actual demand is more likely about 10W, so the 50W Rosco supply should easily power 3 and very likely is enough to power 4.
 
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I have used those scrollers with several different PSUs in the past. Any 24v supply will work fine, as long as it has enough current.
$600 is highway robbery. All a scroller supply does is put 24v on 2 pins, and and DMX on the other 2. Nothing fancier than that. FWIW you could buy any old 24v supply from mouser, a 4-pin XLR and a 5-pin XLR, and BAM, Scroller Power Supply! Especially if you just want to test these before buying a real supply.
 
I have used those scrollers with several different PSUs in the past. Any 24v supply will work fine, as long as it has enough current.
$600 is highway robbery. All a scroller supply does is put 24v on 2 pins, and and DMX on the other 2. Nothing fancier than that. FWIW you could buy any old 24v supply from mouser, a 4-pin XLR and a 5-pin XLR, and BAM, Scroller Power Supply! Especially if you just want to test these before buying a real supply.

That is brilliant, and probably something I would like to take on; for educational value if nothing else.


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I think I still have some of those scrollers, if you want I can check and see what the wattage of the power supply is and how many it can run, if it has a label still.

Also, If you are considering buying a supply, you might just call around to your local rental guys and see if they will loan you one to test with, or maybe bring your scrollers to their shop an try em out. Then they could quote you a price for a supply.
 
And just out of curiosity, did you get other size mounting plates with those? I know you can or could get at least 6.25" and 7.5"
 
And just out of curiosity, did you get other size mounting plates with those? I know you can or could get at least 6.25" and 7.5"

Looks like mine came with 6.25" plates. I wish I had 7.5's to fit my 360Q 6x9's, but then I'd be burning more gel. I suppose I could always have them fabbed - I know a good metal shop.

About that PSU - any info would be great! In the end, I probably won't make my own after reading about opto isolation, etc. Unless there's a handy little PCB I can use. I do have a DFD Optosplitter but I'd rather not risk sending 24v down the wrong line in the first place. I'll probably keep my eye out for used power supplies while trying to borrow/rent for testing purposes.
 
Ill take a look when I have a second. Your right about the need for opto isolation, one reverse wired cable could do a lot of damage. There are some circuits available and they can be built pretty cheap, but unless your looking for a project to tinker with, its probably not worth the effort.
 
Ill take a look when I have a second. Your right about the need for opto isolation, one reverse wired cable could do a lot of damage. There are some circuits available and they can be built pretty cheap, but unless your looking for a project to tinker with, its probably not worth the effort.

Exactly right. And I do like a good pet project... But now is not the time. Nor is it ever, these days. Hah!
 
I have twenty of those scrollers that I have purchased from many different sources a few at a time. The model you have in the pictures, is the second generation of the original chroma Qs. The dip switches indicate that it is self calibrating. The first generation had three rotary switches and were manually calibrating. In every other way they appear the same. They were manufactured by Spectrum engineering in Canada probably on the early 90s. Spectrum also manufactured the early Apollo "S" series of scrollers, plus many other branded scrollers. Camelont in Sweden manufactured scrollers that used many of the same parts and designs for Strand called the "Colour call" but used a five pin XLR. They also manufactured them for Rainbow in Germany. I have some of each and many of the mechanical parts are interchangeable. The one caution on the model you have is to make sure that you tape the ends of the scroll to the rollers. They have a small metal piece that is taped into the end of the scrolll and slips onto the roller. When the unit is calibrating at power up, it will pull the scroll to the end at each end. it is not uncommon for the clop to jump off. If you place a small strip of gaff tape around the roller where the clip is attached it will keep it in place during calibration.
Those scrollers draw a max of 600 miliamperes when moving at their fastest. I have built about ten different supplies for them. The best is a Elation DMX distributor with 8 outputs. four are 3 pin and four are five pin. I mounted a 12 amp 24 volt switching supply obtained from mpja.com to the top of the distributor and ran the 24 volts into the distributor. I changed out the xlr connectors for 4 pin obtained at Mouser.com. Connected the DMX to pins 1 thru 3 as usual and put the 24 volt on pin 4 with the ground of the 24 volt added to pin 1.
All together, I have 61 scrollers of 7 different manufactures and models. All of them are running through a supply distribution system that I built distributed to all of the electrics and various other positions. I run two different systems to each location. one is the standard 24 volt with DMX on 4 pin. The other is Color Ram with supplies that I have built using the circuit boards from the Ram supplies, but with my own much larger 24 volt supplies. On the Ram system I have reversed the pin 1 and pin 4 on all of the scrollers and supply feeds so that 24 volts is on pin 4 not 1. In this way, if someone plugs the wrong scroller into a different supply, there is no damage, it just doesn't work. My theater had this system in for about 3 years this way, with no problems. I started on it over 10 years ago, but it took a little refinement over the years.
 
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All Apollo PSUs will operate just great with those old Chroma-Q scrollers-

Looks like mine came with 6.25" plates. I wish I had 7.5's to fit my 360Q 6x9's, but then I'd be burning more gel. I suppose I could always have them fabbed - I know a good metal shop.

We may also have 7.5 inch mounting plates for these units. These scrollers are the same as the Spectra Q we sold years ago before making our own Smart Color units here at Apollo. :D
 
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Good news -- I bought a used 150w Chroma Q supply on eBay and some cables from Barbizon. The scrollers work great. Of course, what was a cheap project turned in to a bit more than "$10 scrollers" but at least I have 'new' toys!
 
$600 is highway robbery. All a scroller supply does is put 24v on 2 pins, and and DMX on the other 2. Nothing fancier than that. FWIW you could buy any old 24v supply from mouser, a 4-pin XLR and a 5-pin XLR, and BAM, Scroller Power Supply!
Ya i have such a power-supply i do plug it to an opto isolated dmx splitter just to protect other devices. Any cable you make should have heat shrink on the back side of the xlr pins, I did that by wrapping the heat shrink with a small piece of wet paper towel when i soldered the pin.
 
We also make a PSU02 if you'd rather that as opposed to an 8 unit power supply.

If they don't work, we can probably still repair them for you! Just get in touch with the service department
 
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We also make a PSU02 if you'd rather that as opposed to an 8 unit power supply.

If they don't work, we can probably still repair them for you! Just get in touch with the service department

Good to know that there's a Chroma Q guy around here!

I actually purchased a used Chroma Q 150w power supply on eBay for $250 so I'm running with that. The scrollers seem to work fine and actually are surprising how in sync they are with each other. They're going to be a lot of fun and I will keep you in mind for repairs.

I never realized how expensive it was to get scrollers up and running. I think I spent another $200 on cable. Could have made them myself and spent less, but I didn't trust myself to not accidentally swap pins somewhere along the line, and I have so many other things going on that there wasn't much time.

I also looked at prices on gel strings. Wow. I will [try] to self-repair as colors burn out.
 

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