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Using a standard house light bulb

Discussion in 'Lighting and Electrics' started by emanueltech, Oct 22, 2006.

  1. emanueltech

    emanueltech Member

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    Hello guys.

    Im a sound boy at heart but am designing lighting for a show at the moment. Wondered if any of you would be able to help out. Basically i have seen this effect created before at productions but have never questioned how its done. I want to hang standard like 25 watt house light bulbs from my rig. Now how would I go about doing this? Can they be put through dimmers? How would i go about making the light bulb fixtures etc....if anyone can help me real soon it wuld be much appreciated...

    Peace.
     
  2. JSFox

    JSFox Active Member

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    You just want bare lamps hanging down?

    You can get wire-end sockets from most hardware or electrical supply houses. These are often used as temporary light in construction. Get a bunch of lamp cord to run from an edison plug on one end to the lamp housing on the other. This can be plugged directly into a dimmer or you can plug a bunch into plug strips and then plug these into a dimmer.

    If this is for a touring production where it has to go up and down every day get an electrician to make it for you so that you'll have drops at the proper places and all hardwired and safe connections.
     
  3. personalZEN

    personalZEN Member

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    Ikea makes a great lamp socket and drop cord combo for under 8 bucks a pop.
     
  4. ship

    ship Senior Team Emeritus Premium Member

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    A Household type A-Lamp (Edison lamp) is a filament incandescent lamp the same as any stage lighting lamp. Only difference is that it doesn’t have the extra gasses in it to make it have the halogen effect. Otherwise it’s the same basic lamp design and will work on any dimmer.

    That said, you might have to add a ghost loading to your dimmer by way of fixture backstage somewhere to make the fixture work properly on the dimmer if not enough resistance loading is appied to the dimmers. Many if not most dimmers require at least a 75 Watt loading on them to function properly. A 25w lamp could work fine but not shut off, or do all sorts of strange non-off/on type of stuff. Add a load to the circuit and all should be fine. (Dependant upon the dimmer used but overall a safe plan.)


    Normally you want any lamps without safety screens or lenses in front of them to be either caged or “safety coated”. This would be a Teflon or Silicone coating over the surface area of the lamp. Kind of a cool thing - break the lamp, all the glass is retained within the coating. Many lamps are available with this coating on them (gives it a sort of frosted lamp appearance) or many suppliers of lamps can either dip them or get them dipped for you. Also McMaster sells “Colored Light Bulb Covers” which is a silicone lamp cover that slips on over the glass of the lamp in coloring it. This would also fulfill the need for protecting those on stage from the potential of hot falling glass from the overhead.

    All it takes is one drop hitting the lamp or one kid screwing around on stage and you now have someone missing an eye and a tremendous lawsuit. It’s highly recommended that you don’t just use some un-coated or protected lamp overhead. That said, a rock tour with 24 of them leaves in the morning. The designer specified the lamp to be used and as long as I warn the production about the lack of protection on the in this case A-21 silver bowl lamps, liability is not with the supplier of the gear, it lies with the production manager and designer who specified and approved of the gear given a prior knowledge of my concerns as a representative of the equipment supplier for the tour. (This as a theory at least.)

    Ikea does make a decent lamp socket, but for all intensive purposes, it’s nothing more than a clip light socket with the clip and reflector removed.

    There is all sorts of lamp sockets with cable attached to them on the market, someone else mentioned lamp stringers as an option - with or without the cages. There is types of lamp sockets that can clip into the wires feeding them, others that have exposed terminals needing a box around them, and others that are weather tight but need to be crimped to a cable. Lots of solutions, need to refine what specifically you are looking for in concept - just a lamp socket hanging from a cord or a lamp with lamp socket and box around it hanging from a cord.

    A week ago I made two 60" on center 24 lamp "stringers" as similar to the construction light stringers but using lamp sockets that crimp themselves onto the wire where you wish. Two 140' pieces of #12 type MTW wire (grey and black) that was secured to the building on one end, the other end was put in the chuck of my drill. Spun the conductors around and around until both conductors wound around themselves and would tend to stay that way without un-winding. Than it was just a question of marking every five feet and installing the self piercing and protected terminals on the lamp bases onto the conductors. Not a huge fan of this type of lamp base, it at times won't pierce the wire properly (self piercing terminals also both damage conductors and can be high resistance) and are fairly brittle lamp sockets by way of breaking.

    Other options would be doing line splices and splicing the wire from lamp sockets into the power lines - challenge for that would be most lamp sockets use 16ga to 18ga wire and while that's fine for a single lamp, it's hard to crimp such small wire into a 12 or 10ga cable feeding a lot of them. This short of a vulconizing machine and a few other techniques that would be hard to do. Another option in using weather tight sockets with two wire leads off the molded lamp housing would be to crimp to a cable than protect the conductors and crimps from abuse. It's also done but due to how weather tight lamp sockets are constructed, also difficult to make in some way compliant with code or for stage a very heavy duty rating. Construction sockets and some commercial types are available and for the most part for stringers of many lamps on a chain of them the best solution.

    Construction sockets are normally yellow but can be painted with plastic painting spray paint, or in black thru theater supplier sources.

    A few years back I made a few 40' three circuit "Stringers" (Three circuits for more lamps on a 20 amp circuit and for doing chases.) They had lamps 18" on center with all six 10ga MTW conductors twisted around each other and a 1/8" vinyl coated wire rope core. The wire rope terminated in some welded rings for supporting the cable runs. The bundle of conductors were also inserted into a 5/8" fiberglass sleeve for further protection. That's a stringer to an extreme.

    There could be other things you have in mind on the other hand not expressed. Could be the individual lamp sockets (clove hitch and tape the cords to the rigging), could be a stringer. Otherwise it could be more elaborate as not explained in say a chunk of the ceiling having fallen out and it's now a part of the set decoration.

    For one show I did a C-Clamp mounted box that spliced a Edison cable into a piece of BX (AC) flexible conduit and had suspended from it a ceiling box with porcelain lamp holder.
    The BX and ceiling box were grounded by way of isolated ground wire run to the suspended box. Both the ceiling box and BX were supported by a piece of vinyl coated wire rope that was run with the conductors inside the BX and secured to each of the boxes so as to pick up the tension on the BX. BX cable and box plus lamp holder were distressed so as to make look old and really bad looking - there was even a simulated piece of lath attached plaster was affixed to the hanging down lamp socket with lamp so as to help the simulation of a light socket that had literally fallen out of the ceiling.

    Get someone familiar and trained if not a electrician to wire this thing up. There is details like the neutral to the shell and use of polorized plugs that must be followed in being safe. Might seem simple enough but it’s not in making it safe and proper.
     
    Last edited: Oct 23, 2006
  5. emanueltech

    emanueltech Member

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    guys. Thank you sooo much for your help. Its much appreciated. Ship that big post is really helpful.

    Thanks!

    Tom
     

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