Hello I am a Graduate art student working on a sculpture piece that I would like to light up as the viewer gets near. I would like the light to grow in intensity as the viewer gets closer and fade as they step away. If that is too complicated or expensive I will settle for it to just turn on when they get near. I am hoping I can put this together cheaply and simply. I haven't built a circuit since high school, 10 years ago, but I am fairly good with a soldering iron and can follow instructions well. Any suggestions on what I need would be greatly appreciated. I have been scouring the internets but am just confusing myself, so I thought I would ask for some help. Also the sensor itself needs to be small enough that i can conceal it in the sculpture. Thanks!

 

There are circuits for this if you search around:
http://en.wikipedia.org/wiki/Theramin
Frequency to voltage ICs are fairly easy to find so all you would need is a piece of wire running through the sculpture.

 

So I will building a Theremin but have it emit light instead of sound? I am kinda dumb with some of the electronics speak. So I need it all laid out for me. Are there any kits for such a project that I can buy and modify for my use? Or should I just stop by my local radio shack for everything necessary?

 

Paul Godfrey's and simple theramin from this page look easy enough.

http://www.thereminworld.com/schematics.asp

If you connect the output up to something like the LM2917 then it can control the light.
http://www.national.com/mpf/LM/LM2917.html#Overview

 

Woah, looks like some reading. Maybe I'll print it and read it at work. What part do I need to pay attention to? I am assuming I don't need to build the whole thing just part of it to control the light.

 

Yes, I think the whole circuit is important. The Paul Godfrey link looks the best, the simple theramin circuit might work. They are pretty simple as circuits go.
There are probably hundreds of different ways to go about the project.

 

Not exactly what you spec'd...but...could it be a PIR motion detector (automatic light switch) that feeds a PWM fader circuit? The PIR detects the person, triggers a slow fade-on, keeps the light on as long as the PIR detects the person, then slowly fades-off after the person leaves the PIR field.

Ken

 

or use a circuit like this >>http://sound.westhost.com/project126.htm << to control a few 12 Volt LED strings, and use a sensor like this >> http://www.sparkfun.com/commerce/product_info.php?products_id=8958 << to control the brightness of the LED's, you would connect the sensor in place of the potentiometer in the circuit, although you may have to use a transistor, such as an NPN (2N3904) to interface the low voltage (5 volt) sensor to the 12 Volt LED dimmer circuit...


This should cover pretty much all your specs for your project, the sensor is small enough to "hide" it, and the LED controller/Dimmer should do exactly as you want, when a person gets closer to the item, it will output an analog value to light the LED's, as the person gets further away, the light will diminish along with the sensors analog output....

B. Morse

 

OK I am in a little over my head here. I need to keep this simple and easy. I am now trying to think if there is something I can buy preassembled and modify for my purpose. I just don't have the time to create the entire circuit from scratch.

 

benjamin,

Can you describe the floor plan layout out of the area around your sculpture?

Ken

 

Hello I am a Graduate art student working on a sculpture piece that I would like to light up as the viewer gets near. I would like the light to grow in intensity as the viewer gets closer and fade as they step away. If that is too complicated or expensive I will settle for it to just turn on when they get near. I am hoping I can put this together cheaply and simply. I haven't built a circuit since high school, 10 years ago, but I am fairly good with a soldering iron and can follow instructions well. Any suggestions on what I need would be greatly appreciated. I have been scouring the internets but am just confusing myself, so I thought I would ask for some help. Also the sensor itself needs to be small enough that i can conceal it in the sculpture. Thanks!

It would be helpful to those who are providing you assistance to give a upper limit to your project budget.

hgmjr

 

The sculpture is a mixed media wall relief about 18 x 24 and 3 to 4 inches deep. I have about eight of these sculptures that need this circuit so I want to keep it cheap. Around $25-30 max for each piece. The works have many cracks and small holes the sensor can be hidden in. I liked the idea of the Theremin like antenna wire because that would be very easy to conceal. Ideally the sculpture would begin to light up 3-4 feet away and be at full brightness when the viewer is within a foot of the work. If someone is willing to help build these circuits for me maybe I can scrap together more money.

 

Where are you located BenjaminAB?


And, does this have to be battery powered, or do you have access to mains power(A wall socket)?

 

It will be battery powered. They hang on the wall and I don't want to have any cords hanging down. I am located in Scranton, Pennsylvania.

 

Have you already worked out the lights? Are the sculptures to be lighted internally, back-lighted, or indirectly lighted? Since you want them to be battery powered, what type of lamps do you want to use...LEDs?...incandecent?

Ken

 

The lights are behind the sculpture to illuminated the cast resin sections of the pieces. The lights are not in place yet. As for led versus incandescent. I want the soft white light you get from incandescent bulb not that stale bright white from an LED.

 

Then be aware that you will need a bigger battery for incandescent lamps than LEDs. Maybe combinations of white, with yellow and/or red LEDs at lower current levels, to soften the color.
How much room do you have behind/in the sculptures got the lighting/battery/controls?
Pictures maybe?

As you can see, "the devil's in the details!".

Ken

 

Yeah I realized that with incandescent bulbs. Don't they now make soft white LEDs? There is a good amount of space behind each piece. Plenty of room for a few batteries and a circuit board. I will try to provide some pictures. They are still in progress so things are incomplete.

Details make all the difference. For sure.

 

OK here are some pictures.
The works consist of a porcelain face plate that has openings cut into it. Clear resin fills these openings. The resin is backed with a thin layer of opaque black resin. To really get the idea of depth the clear resin needs to catch some light. That is why I need the little lighting circuit so the viewer can really sense the depth in the resin filled openings.
The first picture is just the piece. In the second picture I tried to illuminate part of it with an LED headlamp but it is the stale blueish white light that I don't want. Still gives you a pretty good idea.
The pieces are pretty flat now but the sides are being built up with different materials so they stick out of the wall between 3 and 4 inches.

 

I think you need to spend some time with LEDs to find a color you like. You can use RGB LEDs to find a color combination you like. You can also diffuse and soften the light to your taste.

There are devices that can do what you want. It may take most of your budget.

A micro controller with an ultrasonic distance detector could activate and change the brightness of an led according to distance.