Color and voltage of LEDs
The operating voltage of LEDs depends on the color. This is an indication of discrete energy levels and the photon character of light.
Information and ideas:
The abstract principle of the quantization of energy in the form of photons is demonstrated clearly in an extremely simple experiment with four LEDs and a power supply unit. Red LEDs light up at a voltage from about 1.5 volts, yellow from about 1.9 volts, green from about 2.3 volts and blue from about 3.3 volts.
Instructions for building a variable LED color mixer can be found in the experimentation instructions “Experiments – energy quantization with LEDs" on the media portal of the Siemens Stiftung.