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What is it?

Discussion in 'Question of the Day' started by ship, May 27, 2016.

  1. ship

    ship Senior Team Emeritus Premium Member

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    Newest version, last year I made a 48 way version taking up an entire rack.

    What's iti's purpose? Given resistors are the equivalent, couldn't they do the same? Why is such old school technology coming back?
     

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  2. Wheezy

    Wheezy Member

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    Load Bank.

    A few reasons off the top off my head to use this one are:

    * Cheap and Simple
    * By changing lamps of different wattages, you can vary the load.
    * If it's a road setup, easier to pop over to Walmart and pick up replacement lamps. Not so with resistor packs.
     
  3. Skervald

    Skervald Active Member

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    I was going to guess tanning booth for short people or super mega EZ bake oven. Sure you don't want to reconsider?

    In all seriousness, I understand the concept but what's the most common situation you find yourself in where you need to add a load?

    Sent from my SM-G900V using Tapatalk
     
  4. JD

    JD Well-Known Member

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    From about 1960 to 2010 there wasn't much use for these, but it's funny that our newest technology necessitates something from the old world for the exact same reason!
     
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  5. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    A sense of scale would be good. It looks like the box has rack ears made for mounting in a 19" rack?

    It also appears to have Socapex in and out, so I wonder what powers the two fans?

    Last question, are those candelabra socket s (E-12)? Wouldn't Edison screwbase (E-26) have been more available?

    EDIT: What's that weird mess in the lower right-hand corner of the box, and why is there a 3" (?) piece of wood (lath strip (?)) next to the bottom socket?

    One more: is this creature UL Listed? Does it need to be?
     
    Last edited: May 27, 2016
  6. Brad.O

    Brad.O New Member

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    One common use for this would be using LED fixtures on dimmers not designed for low wattage loads - by placing a synthetic load in parallel withe the low wattage, you create a load consistent with what the dimmer was designed to accommodate.

    Also works good for keeping you warm on cold show nights :) Lutron (LUT-LBX) and other manufacturers make synthetic loads that can be used for the same purpose - but at higher cost - they do come with a UL listing though.
     
  7. Amiers

    Amiers Custom Title of Awesomeness

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    Dual purpose heater and light source?
     
  8. Wheezy

    Wheezy Member

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    If you zoom in you can see mounting holes around the lamp bases. Almost looks like it had resistors that were replaced some time with lamps.

    The background items throw the scale off, as if this thing is much bigger than a 19 inch rack.
     
  9. ship

    ship Senior Team Emeritus Premium Member

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    Mess in the lower corner is IEC feed thru power and feed thru for the fans to the other 3-space rack mount panel. E-12 as surmised for base but more for wattage and incandescent long life version in conserving heat from output as low as possible. You guys are good, especially JD and overall all repliers!!

    Lower corner is silicone insulated for the wires under a bridge to control for wire sag from the IEC. Messy in look but function is to ensure the wires cannot get cut in strapping bridge housing them in. UL listed, no a prototype at the moment that could be useful on a tour as with a 48way version (photos of external lamps in entire rack used for it as opposed to lamps inside rack panel.) Totally agree with the history and how it was a funny to have to do such a thing last year. But it worked well and prototyping smaller versions.

    Zoomed in mounting holes was for two lamp sockets per circuit (prototype) in not fitting with both 25w and 60w lamp in the space for original goal. Also looked into light shield wlding glass viewing glass to verify all six lamps were working but not enough room so far in concept.

    "Lutron (LUT-LBX) and other manufacturers make synthetic loads that can be used for the same purpose - but at higher cost - they do come with a UL listing though." Thanks, I will look into that info and in part why I'm posting.

    Application as above, LED lamps too low in load for control from normal or LED dimmers.

    Purpose, dummy/resistance loading but one not seen in light output on stage or even back stage. Attached, photos of an entire rack devoted to 48 channels of incandescent loading per dimmer channel. Last year built it, two shows used so far with it. That 30+ year old road case the photos are on, are currently at R&R for total re-build of the case. Funny, they at R&R asked the same question about UL listing, this after explainging what it was and why it was needed, than the whole concept of what it does.

    Prototype stage... fans in use not powerful enough to properly cool the 6x60w internal box lamp assembly. Lots of details but project put aside for a few more weeks. Should work in concept, but I have a child bed to build firs,t in it not working for tour potentially needing it next week, the R&D will take more time than I have available at the moment.
     

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  10. Amiers

    Amiers Custom Title of Awesomeness

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    For cooling problems you should add another 2 sets of fans where you have the louvers and push the hot air out while pulling fresh air from the back. I also feel that you are having problems with cooling in the 24x2x60w Roadcase as well. I would drop another set of 3 fans on the bottom of the second row and then direct the air with some sort of curved sheet metal like a 90 degree duct. Then add fans on all 3 side vents aswell to push out extra heat. To keep the sleek design of the Roadcase I would keep the sidewall fans inside and behind the vents.
     
  11. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    Funny that in ten posts, no one has mentioned the mystical, ethereal, commonly-accepted term for what the device is.
     
  12. Scarrgo

    Scarrgo Active Member

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    Ghost Load?
     
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  13. ship

    ship Senior Team Emeritus Premium Member

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    Cool, thanks on design ideas further. Yes, ghost load. 48way rack already been on two shows and worked well, but will consider changes given it was 25w loading per circuit in last use thus ran cooler than goal of 60w.
    Project(s) on back burner until probably fall at this point - at best. Encouraged by the above comments though - thanks. R&D is a really cool thing given I don't design shows these days.
     
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  14. Amiers

    Amiers Custom Title of Awesomeness

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    I would love to do R&D one day. Nothing sounds more fun than creating something about watching it become something at the end of the day. Even if it is a flop and you have to go back to the board.
     
  15. MikeJ

    MikeJ Well-Known Member

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    I guess I don't get it. I understand what it does, but what specifically are you using this for? I take it these are for "dimable" LEDs that just don't work right on existing dimmers? I could see this on house lights that that are all can lights in a theater, but I would not imagine most of those situation would use socapex. What in a touring application is this used for, and are there not better solutions?
     
  16. Footer

    Footer Senior Team Senior Team Premium Member

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    Festoons..... all the hipster rage these days.

    Sent from my XT1585 using Tapatalk
     
  17. RonHebbard

    RonHebbard Well-Known Member Premium Member

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    On the musical Tommy, the one with all of the pinball machines, we had many transformer coupled (inductive) loads. Having a resistive load in parallel allowed the dimmers of the day to work MUCH smoother in the low end and deal with the transformers with little noise and without mechanically jarring the heck out of transformer windings and laminations. The Canadian shop I was with built Tommy for Offenbach (Frankfurt am Main) Germany in 1995 and the Germans were prepared with small two and three lamp fixtures appearing much like small traffic lights. What caught us off guard in Germany was having 440-ish dimmers supplied as a small mountain of six and twelve packs but at least they were ready with dual-lamped dummy loads for all specified dimmers, something in excess of fifty. Checking the lamps in the dummy loads was part of the lamp check. Every dummy load had two lamps as, if you only had a single lamp per load, you can guarantee it'd burn out at the worst possible time, especially when you're running a great many chases.
    A year later, 1996, we built all of Tommy a second time for its U.K. premier in London's West End where the Brits weren't quite so prepared for dummy loads and the quantities required.
    The Who's Tommy originally came together in La Jolla California, toured the U.S. to Broadway's St. James; then, while still running in the St. James, a first international tour, U.S. and Canada, was spun off prior to the German and U.K. productions. Mr. Townsend was proud as punch when he finally got to see Tommy in his homeland.
    Basically, there are many uses for dummy loads although some uses have followed the dodo with the advent of IGBT dimmers.
    Toodleoo!
    Ron Hebbard.
     
  18. Evans Poulos

    Evans Poulos Active Member

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    Would it be reasonable to wire a bunch of panel mount indicator lights, 1 in series with each load lamp, such that if the lamp inside were to fail, the corresponding indicator would not illuminate? That way you could close up the case to shield the mini sun...
    Would it not be possible at that point to make the indicator panel be usable remotely with the appropriate multi conductor cable(s).
    I'm fascinated by this project to an absurd degree!
     
  19. ship

    ship Senior Team Emeritus Premium Member

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    Had to build two more 48way dummy loads recently. Wanted to do a resistor based version but wasn't time.
     
    Last edited: Sep 30, 2016
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