Need advice on how to cobble something together...

[Serapium]

Hi all. New to board, but not a total rookie where it comes to lighting. Have an odd situation though that I'm hoping someone can help with.

Putting on a production of Zombie Prom in Oklahoma and need to create a fog-filled box with green lights in it that can be controlled by a person backstage with just a rheostat or dimmer switch. Budget is REALLY limited, so I'm having to cobble together what I can. All the instruments owned by the venue are in use for the main stage front lighting so I can't just use the light board and a couple of instruments with gels on them.

I've got the fog filled box part worked out, just need advice on the lighting component. I went to the salvage yard and got four sealed-beam 12V headlights from a junk Silverado. Going to build a custom box to mount these in to illuminate the foggy box, but not sure how to power them on a budget. My first thought was a variable 12V power supply but they're more than I have to spend.

Do you think I could use a car battery? If so, what could I use to act as a dimmer? (the lights need to get gradually brighter over the course of about four minutes.) Would a standard household dimmer switch handle the load do you think?

 

[Amiers]

Household dimmer is AC and it won't work. You need a DC Dimmer that can handle the amps put out by the 4 lamps. Also a car battery will work or a deep cycle boat battery, if the junk yard is your outlet look for a newer car with rear end damage.

 

[Serapium]

Any idea where a guy might find a DC dimmer for cheap somewhere? Or even free? Something I could repurpose from something else? Thanks!

 

[Amiers]

Again you you have to know the amps that the lamps pumps out. The link I posted has an 12v 11a dimmer for 40$ that is as cheap as I can think of. Outside of ripping apart a dash at the junk yard to pull out a in dash dimmer but that works for the dash lamps not headlights. It might be time to go back to the drawing board and think of some other way to light up your foggy box :/

 

[MNicolai]

FWIW, green Christmas lights are dirt cheap and if I understand your idea correctly, they may work for what you're doing and can be placed on a standard AC dimmer. You could buy a few strings and mount them in the box. Just make sure you've got a little ventilation because in a fully enclosed environment, the lamps in the light strings will burn out faster.

 

[lwinters630]

If you are going with the car headlights, use a variable voltage dc transformer like from a train set. 0-15 vdc.

then again why are you not using ac power to incandescent green bulbs with household dimmer?

 

[Serapium]

If you are going with the car headlights, use a variable voltage dc transformer like from a train set. 0-15 vdc.

then again why are you not using ac power to incandescent green bulbs with household dimmer?

I chose the headlights because of the directional nature of the light beam. Was going for a specific look. I guess I could use typical AC spotlights and mount gels in front of them. Maybe that makes more sense....

 

[n1ist]

What about green PAR38 or R20 bulbs?
http://www.bulborama.com/90-WATT-PA...N-PAR-GREEN-LIGHT-BULB-4-000-HOURS-p1660.html
http://www.bulbamerica.com/sunlite-50w-r20-120v-red-colored-r-type-light-bulb-1.html
/mike

 

[lwinters630]

I chose the headlights because of the directional nature of the light beam. Was going for a specific look. I guess I could use typical AC spotlights and mount gels in front of them. Maybe that makes more sense....

The Gam stick up light has a great spread and is bright. You can gel it and put it almost anywhere.

 

[ship]

Lamps don't care what type of AC/DC voltatage is applied to them over a short run, and we are all collectively forgetting where the start of modern PAR VNSP lighting has come from in history for the most part. GE had a long article about what's going to happen to the filiments to the lamps, but that's a long term thing or perhaps short term thing dependant on age of lamp.

Voltage will become important as unless you are planning to chain say 11x lamps in series you will probably blow all by way of the oldest in age lamp and it arching in filament sufficient to blow others.. Even with none blown, you are for a show depending on nothing blowing and not blowing out others or the rest.

On the other hand, converting to 12v AC would be cheaper as long as a transformer to do so large enough for as many as you plan to power up. Than only all from one transformer. Not cheap solution, perhaps calculating the load and buying a few transformers for the most cost efficient load on them.

Beyond that, dimmers while variac perhaps best, but in general transformers don't like dimmers is another point. Just don't like signwaves cut and architectural dimmers easily get killed off for odd stuff.

If going to scrap yard, any number of more appropriate AC voltage fixtures might be found from old track lights in lots of sizes to even stage light fixtures. At one point I had an entire collection of track spot fixture out of some store that were spot as normal in hang, that I was using for a theater. Bought for I think $5.00 each and converted from track light to clamp. Got the idea perhaps but shoot for better - more what you can use gear.