LED Color Mixer
Recommended for grades 9–14.
Introduction
LEDs (Light Emitting Diodes) are long-lasting light sources made from a special semiconductor material that converts electrical current directly into light. Unlike incandescent lamps that emit broad-spectrum white light (all the colors of the rainbow), LEDs emit a small wavelength range that appear as a single color. In the human eye, the receptors that interpret hues of color are called cones. Cones can be classified into three basic types based on their responsiveness to long, medium, and short wavelengths, or red, green, and blue color. A 3-color LED (sometimes called an RGB LED) emits the three colors of light (red, green, and blue) that trigger the cones in the eye. A RGB LED actually contains three individual LEDs encased in one shell. It looks like a single LED with four leads or wires – one for each color and a fourth lead for the common ground. Additional colors can be perceived by the human eye when the individual LEDs are illuminated simultaneously in different combinations.
Objectives
In this Project, you will build a circuit and write a LabVIEW program to illuminate the three different colors of light (red, green, or blue) in a RGB LED. The user should be able to select any one of the three colors by name from a front panel control and be able to turn off all three colors while the program is running. Since LEDs can be destroyed if too much current flows through them, you should wire each of the three leads in series with three current-limiting resistors.
Sensors and Equipment
This project requires each of the following Vernier sensors and equipment (unless otherwise noted):
Additional Requirements
You will also need a SensorDAQ interface and LabVIEW software for data acquisition.
Download Experiment Preview
The student-version preview includes:
- Step-by-step instructions for computer-based data collection
- List of materials and equipment
The preview does not include essential teacher information, safety tips, or sample data. We strongly recommend that you purchase the book for classroom use.
Standards Correlations
No standards correlations for this experiment.
Experiment 3 from Engineering Projects with NI LabVIEW and Vernier Lab Book
Included in the Lab Book
Vernier lab books include a CD with word-processing files of the student instructions, essential teacher information, suggested answers, sample data and graphs, and more.