How to demonstrate RGB=White to kids

[robj]

Anyone have a good way to demonstrate the additive property of combining Red, Green and Blue result in white light? I want to show a group of kids but can't find a good demo project. Tried flashlights with home made filters but can't get the mix to work.

Ideas welcome!

 

[Madko]

Other then using a pixel and setting it red, green, blue then all together ( had to say that as this is a lighting forum), if you can make a round wooden disc, divided evenly into three sectors. Paint each sector red, green, blue. Drill a hole in dead centre and put a long bolt and clamp it into a cordless drill. Hopefully you can get the colours right then hopefully at a high speed (theorically) white should appear!

 

[penguineer]

Sort of a class thing?

How about dumb nodes with seperate red, green, blue channels and a physical dimmer switch for each channel - using computer+software+magic boxes in the middle makes the whole thing look too staged, get the kid(s) to control it.

Get a volunteer to control each dimmer
- each volunteer plays with their own dimmer in turn so they can see the control they have over the colour(each returns to zero after their turn)
- each colour gets turned on slowly in turn (slow add to white)
- get them to make specific colours (which colours add to which to make what)
- free play, see what colours they can work together to mix

Should need a dumb string, power supply and three dimmers as well as cable to connect together.

Dumb String:
http://www.aliexpress.com/store/product/IP68-DC12V-input-12mm-through-hole-LED-channel-letter-RGB-color-100pcs-a-string/701799_522236867.html

Single dimmer:
http://www.aliexpress.com/store/product/LED-Dimmer-DC12V-24V-input-P-N-LN-XDIMMER-1CH-12V/701799_307327655.html

Three dimmers on one block:
http://www.aliexpress.com/store/product/3-channel-led-constant-voltage-dimmer-DC10-30V-input-6A-each-channel-output/701799_533629672.html

How does that sound?

Cheers

 

[nato595]

I like the other ideas so far. If you like the method of 3 dimmers on one block (one for R, G, and B) and want to buy from the US, I have and recommend this one:
http://www.environmentallights.com/led-controllers-and-dimmers/12-volt-dc-led-dimmers/13833-rgb-3-dimmer.html

 

[robj]

Outstanding ideas guys. Thanks! Rob

 

[BradsXmasLights]

I remember the RGB Colour mixing display at the Queensland Museum as a kid. It was just 3 dimmer sliders with separate stage lights for each colour. Worked a treat!