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Picture of #STEMontheCheap RGB Light Show Paper Circuit

Let students explore the REAL primary colors and not the lies taught in far too many classrooms. If you ask me, a physicist, what the primary colors are, I would ask you a question. Are you talking about light or paint? The answer is, in fact, different but connected in the most beautiful, symmetric way when it is taught correctly.

In NO case are the primary colors red, yellow, and blue!

The RGB Light Show Paper Circuit will introduce students to the primary colors of light, used for color addition, which are red, green, and blue. It will also introduce them to the secondary colors of light, which you get by mixing combinations of two primary colors together. This demonstration can also be done at full scale using red, green, and blue flood lights with a setup that costs about $60. When the supplies are purchased in bulk for a classroom, the RGB Light Show Paper Circuits cost under $1 per circuit.

NGSS Standards

(NOTE: For preschool and early elementary students, the teacher would likely build the RGB Light Show Paper Circuit and the students would use it to make observations, notice, and wonder.)

1-PS4-2 Waves and Their Applications in Technologies for Information Transfer: Make observations to construct an evidence-based account that objects in darkness can be seen only when illuminated.

1-PS4-3 Waves and Their Applications in Technologies for Information Transfer: Plan and conduct investigations to determine the effect of placing objects made with different materials in the path of a beam of light.

4-PS3-2 Energy: Make observations to provide evidence that energy can be transferred from place to place by sound, light, heat, and electric currents.

4-PS3-4 Energy: Apply scientific ideas to design, test, and refine a device that converts energy from one form to another.

4-PS4-2 Waves and Their Applications in Technologies for Information Transfer: Develop a model to describe that light reflecting from objects and entering the eye allows objects to be seen.

MS-PS4-2 Waves and their Applications in Technologies for Information Transfer: Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials.

Step 1: LED Prep and Warning

Picture of LED Prep and Warning

LEDs (light emitting diodes) have a negative (short) lead and a positive (long lead). As you can see, the difference in the lengths of the leads is very slight. To ensure you can tell the leads apart, use either scissors or wire cutters to snip off an extra 1/8" off the negative (short) lead, as shown.

Be sure to check your green LEDs using the battery. Sometimes you get good, brilliant green LEDs and other times you get an orange-ish, green LED like the one on the right. You can also check the green LEDs with other colors. If the green lights with the red and yellow LEDs and not with the white and blue, it is a bad one. If it lights a full, brilliant green with the white and blue LEDs, then you have a good quality green LED. In the bulk LED batches where you get five different colors, the green LEDs have often been poor quality LEDs. Replace them with the suggested 3 mm green LEDs you can purchase by themselves in the supply list.

I love how this setup is small and easy so I can realistically have each group of students explore this on their own (as opposed to the whole class sharing one).
Thanks! Students really love making them and then taking them home to show their families. The whole class version of this demo is pretty cool too, though!!!

oliviamudong3 months ago
I think this project would be more fun and simple if you used a circuit scribe pen
TheSTEMAZingPro (author)  oliviamudong3 months ago
Perhaps but then it wouldn't really fit the #STEMontheCheap qualification. I hope you will give it a go! I work in Arizona where we are hyper-under funding education - nearly the worst in the country. So, it is not realistic to imagine getting a classroom set of circuit scribe pens to make this accessible to teachers and students. This version costs less than $1 per circuit which is feasible.
jessyratfink3 months ago
Great project! :D
TheSTEMAZingPro (author)  jessyratfink3 months ago
Thanks! It has gone through many iterations and has been well tested with teachers and students in the U.S. and Honduras.