Ang LED The LED — where the colour really comes from

1. Ang liwanag ay photon Light is photons

Nakikita natin ang 400–700 nm. Ang remote ng TV ay 940 nm: hindi nakikita, pero kita sa camera ng phone. We see 400–700 nm. A TV remote is ~940 nm infrared: invisible to us, visible to a phone camera.

2. Aling paa? Which leg?

Mahabang paa = anode (+). Patag na gilid at malaking plato sa loob = cathode (−). Long leg = anode. Flat edge and the bigger plate inside = cathode.

3. Sa loob Inside

Maliit na semiconductor (PN junction) sa loob ng tasa na nagre-reflect, may manipis na wire, sa loob ng epoxy. A tiny PN junction chip in a reflector cup, a hair-thin bond wire, all inside epoxy.

4. Boltahe at resistor Voltage and the resistor

Pula ~1.8 V, berde ~2.2 V, asul/puti ~3 V. R = (V_supply − V_LED) ÷ 0.020 A. Each colour needs its own resistor.

5. Saan galing ang kulay Where colour comes from

Band gap (eV) → wavelength: λ ≈ 1240 ÷ E. Hindi ang plastik ang nagbibigay ng kulay. The material's band gap sets the colour, not the plastic.

6. RGB

Pula + berde + asul = anumang kulay, pati puti. Ganito ang bawat pixel ng brownout lamp. Red + green + blue make any colour, even white. Every pixel in the brownout lamp works this way.