Automated Fixtures Converting a VL500 80v

[Les]

I have posted about them before, but I have 5 VL500 80v fixtures in my collection, which I occasionally use on my own shows (mostly theatrical).

These fixtures are unfortunately members of a dead product line, and parts are getting increasingly harder to find; especially in the 80v dimmer module, where some parts are proprietary (and discontinued). As luck would have it, I have one unit with a dead dimmer module. While I'm working on getting (used) parts, I realize that as time goes on, this may be an issue - especially since no one wants to sell me raw components (assemblies and boards only). And then I got to thinking...

Mind you, this would be 100% my liability and would void all UL listings, but for experimentation's sake and thinking out loud...

I wonder how hard it would be to remove the dimmer module and replace the 80v socket/lamp system with something like the TP220XL + GLA.

In order to control intensity, I'd run wire through the yoke/base to a pigtail, to be controlled by a remote dimmer/rack, much like the VL1000 Tungsten. Of course I'd source the same type of wire generally applied to this task and loom it all the same way.

Inside the fixture I'd want some sort of relay so the lamp can't be powered up without the rest of the fixture being on (since there are microfans on the MCB). The 80v dimmer takes two lines in, and I'm in the process of tracing those wires. They either come straight from the base's Neutrik input (which would be great! No re-routing!) or the MCB - which would then be removed. Depending on the voltage on those leads, which would be metered but I know has to be greater than 80v and probably closer to 120, I'd buy a relay with a matching coil to make contact with the lamp. These leads *should* apply voltage once the fixture is powered anyway. There are also two smaller leads terminating to a Molex in that area, which I suspect is signal for the dimmer. They could be capped or removed.

This would obviously cause the DMX mapping to be "funky", lacking a dimmer channel, but my initial thoughts are that the fixture itself would operate fine. There would be some sheet metal work involved in mounting a relay and adding a cover plate (and probably some counterweight to compensate for the missing ~three-pound dimmer), but nothing too hard.

Again, this would all be experimentation on my own equipment, but at first blush, it sounds completely doable.

 

[cbrandt]

No luck with lightparts? They have a lot of parts listed as available. They also might be able to make some suggestions/provide parts to just put in the arc ballast. No matter what you do, it probably requires a new reflector. I don't have any experience with those 80v lamps, but I can't imagine that something else is going to line up nicely into that reflector to give you good light out the front.

 

[Les]

I'm not sure if anyone is following this (TL;DR: converting VL500 with internal dimmer and 80v lamp to a VL500 with external dimmer and 120v lamp), but I thought I'd give an update, at least to gather my own thoughts.

Apparently, I'm not the first to come up with this conversion. I was talking with Don Pugh at LightParts yesterday and he said they used to modify Studio Colors this way and said it worked great. Then I spoke with a friend in the Vari*Lite service department and he confirmed that it can be done. VL even made this model specifically for external dimmers. Sure enough, the fixture menu has a setting for "External Dimmer". Perfect.

The original lamp socket (usually powering the 80v 1200w lamp) is a G22 and should work well with the Philips EGT lamp. I believe it's the same lamp they use in the VL500D. The reflectors are the same across the line so there shouldn't be any worries there.

I removed the DMX line running from the MCB to the internal dimmer. The fixture won't need it and it's one less thing to have hanging around waiting to get tangled in a tilt belt. At first I thought it would be a good idea to make this mod reversible but now I'm thinking screw that. This is how it is now.

The 80v dimmer was powered directly from two leads originating in the base of the light and tied straight in to the mains input. This is a lucky break since it means I won't have to route any new wiring through the main harness (which needs to flex - a lot) I'll just use what's already there. I will remove these leads from the terminal block directly behind the Neutrik input and connect them to the output of a relay, which will also be located in the base (there's some space in there so I should be able to make things fit). The input of the relay will come from a new line cord. This cord will exit from a currently unused jack that VL put in for some kind of testing option. I think I can live without it. The terminal block will then get two new leads which will power the coil of that relay (meaning I need a relay with a 120v coil).

I thought about powering a 12v (or whatever) coil voltage relay from the LVS (low voltage supply) which is also located in the base, but I've decided against it. I don't know how much headroom they factored in to the power supply and I don't want to drag it down with an additional load.

Up in the arm of the fixture, I will connect what was the dimmer supply directly to the lamp leads (which I needed to replace anyway). I will leave the old dimmer in place due to the fact that the fixture was designed and balanced accounting for that extra weight. No other fabrication needed.

So... It looks like this modification will work well and really not cost that much money. The most expensive part will be the 1,000w lamp ($20). The relay should be $10-15, and the rest is just wiring. Edit: Just kidding - flexible silicone cable rated to 200C is super expensive, on the order of almost $8/ft!). I will need 2-4' per fixture (five fixtures total, so about 25' should be safe).

 

[cbrandt]

Thanks for the update! We see so many of these projects fail, it is nice to see one moving forward.

 

[JD]

Quick question/thought:
What is failing in the dimmer mod?
The most likely part is the thrysistor (SCR/Triac/SSR/IGBT.) Even if it is a proprietary part, there should be a generic workaround, space permitting. Yes, it will no longer be a fixture with any type of approval, but that sounds like a given. As long as the processor is producing a firing logic output, making up a firing circuit and converting to generic device should be a piece of cake!
Always had a soft spot for those wonder-vane Varilites like the 500! Such a uniquely over-complicated system. Almost a the steampunk of lighting fixtures!

 

[Les]

Quick question/thought:
What is failing in the dimmer mod?
The most likely part is the thrysistor (SCR/Triac/SSR/IGBT.) Even if it is a proprietary part, there should be a generic workaround, space permitting. Yes, it will no longer be a fixture with any type of approval, but that sounds like a given. As long as the processor is producing a firing logic output, making up a firing circuit and converting to generic device should be a piece of cake!
Always had a soft spot for those wonder-vane Varilites like the 500! Such a uniquely over-complicated system. Almost a the steampunk of lighting fixtures!

I love the Dichro*Tune "twisty vanes" color changer! I know LED's could kick these fixtures' butts in most cases, but you can't beat the 'eye candy' factor that they have. Even though it's way over complicated and really quite delicate, I've never had an issue out of the system. It's surprisingly resilient.

What seems to be failing is one through-hole ferrite (inductor?) and two large common-mode chokes seemed to have gotten very hot. One cracked and the other looks "bubbly". I looked around online and couldn't find the parts they were using, and a local electronics/hobby store thought they were custom run parts. I also found that the fan motor in this assembly was very oxidized - either water damage or extreme heat. It was locked up, so maybe that caused a cascade of failures.

I actually haven't had many problems with the dimmer modules (which are IGBT), but I figured this one would be hard to fix and it's only a matter of time before the rest start having issues. At first I liked the "standalone" nature of the lights, but it's actually quite difficult finding enough constant power when I'm using 5 of them at 1200w each in a community theatre or similar venue. Letting the venue's dimmer racks handle the lamps and only needing constant power for the electronics/logic seems to be a pretty good compromise. That said, I am open to trying to repair the dimmer that is bad. I enjoy the education.

Full PCB

"L701" is blown. Apparently it is a ferrite. The board is labelled "Bead 1".

This common-mode(?) choke seems to have gotten pretty hot. Notice also the rusty fan motor with a piece of plastic stuck in the blades.

This choke's potting has cracked in a few places. Definitely not normal when compared with the working units.

Here's the model number for one of the chokes. I was able to find Falco online, but not that part. They do manufacture custom runs, so that's possibly what this is.

 

[JD]

I would say the fan was the cause of the problem. Cracked potted chokes can be like that for 20 years and not fail. After all, it's basically #14 or #12 enameled wire wrapped around a torad and potted. Same is true with the bubbly one. It is the blown bead which I find most interesting! It almost looks like a snubber across the dimmer output. Usually, a "bead" is just a piece of #16 looped through a ferrite, but this one deserved a closer look. The white ghosting on the one side does look like it spewed something but that concept is hard to wrap my mind around! If you have other units that do not look like that and the fans are running, I would not worry about them all doing this. It doesn't take much heat to destroy something if the airflow is cut off. Just think of how hot a 12 watt soldering pencil gets!
If the unit is not working, I would suspect there is yet another failure somewhere. Easy enough to meter the chokes, but I suspect they will check out.

 

[Les]

The electronics gurus I talked to were equally perplexed as to why a bead blew in that fashion, though I didn't mention the fan. I did talk with a guy in Canada who repairs a lot of movers (particularly VL) and posts the videos on YouTube. He said they always blow in the same place and he repairs about two per month, though I'm not sure if he was exaggerating or mixing it up with something else. I think I would have found more discussion online if that were the case. I personally am not very experienced with the reliability of these, since I bought them about two years ago and only two have been up and running during that time (and not even continuous). Hopefully once I get everything done with them I can find more excuses to put them on shows. I do agree with you that the chokes are probably fine. After all, they are just turns of copper wire, and I also think the frozen fan was the catalyst of the failure.

I had tested all the fixtures when I bought them and *thought* they all worked, so maybe this one isn't completely dead. I just saw all the carnage and figured it probably needed some attention.

On another note, do you have any recommendations on some nice, bendy lamp wire? I found some stuff online that matches the specs of what was originally used (minus the 5KV rating, which was pointless on an 80v fixture to begin with) but it is outrageous. It only has to go from the socket to just inside one of the arms so I guess it doesn't have to be too, too flexible. I'll move one of the heads by hand and see what kinds of stresses are actually at play. VL probably used this particular wire because they already had a spool of it for their arc fixtures. I assume SF-2 is out of the question.

 

[Les]

Progress report:

The lamp wire is on order. Pretty tough finding a type that would meet all the criteria (14-16 gauge, 200°C rating, flexible, high strand count) and a supplier who would provide small quantities. I bought 50' for a little over $50.

I also received my "test" relay today. It is nice, small, and will easily fit where I need it. Hopefully I can figure out how to mount it this weekend. I'm tempted to epoxy it in to place, since the ideal mounting method would require drilling holes where no drill can fit (would need a 90° driver because the mounting area is recessed in an aluminum casting), but I might be able to design some type of bracket system. Epoxy will be strong and permanent - but maybe a little too permanent. Plus, I always try to design/build my projects as if a professional will see them. I don't want them to open it up and say "well that's all a bit how ya doin."

But depending on how the bracket works out, I just may stoop to that level.

 

[Les]

The VL500 project is complete. Each fixture fought me nearly every step of the way, but it got done. There were a lot more small parts to source than I realized.

1). Relays (Zettler Z2280-1A-120A)
2). 200C lamp wire - high flexibility (this was hard to find, but I finally went with Daburn #2616)
3). Fiberglass sleeving, black (1/2")
4). Fiberglass sleeving, white (1/4")
5). Insulated crimp terminals
6). 14/3 SJOOW for pigtails
7). Strain relief
8). Decent Klein crimper (so much better than those all-in-one crimper/stripper tools)

I also over-bought in terms of heat shrink and various small items I ended up not using.

But the end result is a group of five VL500's that can have their lamps powered from a dimmer and the electronics powered by constant circuits (but won't allow the lamp to run without the rest of the fixture powered up), which really helps in those spaces that don't have relay cards for their dimmer racks. It's easier to pull constant circuits for a several small loads rather than several 11-amp loads.

Here are a few pictures, in no particular order. I also didn't get pictures of every step or process (ex: installing and wiring the relays in the base of the fixtures), but I can take other photos if asked.


Thanks to the flexible software, I was able to set the MCB's to "external" mode. Doesn't seem to change much, but at least the fixture knows what it is. It seems that VL uses the same MCB and software across all versions; allowing the user to select between Arc, 80v Internal, 1,000w Internal (aka Universal Dimmer), and External Dimmer.

New cord exit (on right)

Yoke/arm before adding new lamp leads:

Bell housing with reflector removed - about to start pulling wire through. The rear color bulkhead containing magenta and blue dichroic panels also needed to be removed for this process:

Lamp cap assy with new wires and fiberglass sleeving installed.

As I go through and install new lamps (which are on order), I will take more 'completion' pics . I left the original 80v dimmer in place, but I am considering removing the inactive PCBs since they have components that could snag the lamp leads. I'm sure the ~few ounce weight difference won't affect things too much, especially since I never side-hang these.

 

[Evans Poulos]

Congrats on getting them working!

 

[soundman]

Nice work!

 

[Scarrgo]

Love to see it in action when your done...great job!

 

[Les]

I'm currently wishing there was a such thing as a bi-post (G22) - anything else socket adapter, so I could install a ~100w 'test lamp' and run all five at once for testing (at home) without burning the place down. I'll admit that I'm tempted to take a bandsaw to my old 80v lamps but aside from the safety implications, it would feel like a sin to destroy what are still perfectly good lamps - although I have no use for them any longer.

 

[JD]

What, no Dryer or Range outlet in the house ?

First thing I added when I moved in! One has to be able to play with new and improved toys!