PAGE 019 OF 150 · COLOURS, SIZES & TYPES
Yellow and Amber LEDs
Amber is common for warning and indicator lights.
LED SYMBOLTriangle points from anode to cathode; the arrows show light leaving the part.
Yellow and amber
Yellow LEDs emit near 585 to 595 nm and amber slightly longer, around 590 to 610 nm. Both use phosphide-based materials with a forward voltage of about 2.0 to 2.2 V.
Where they are used
- Turn signals and hazard lights on vehicles
- Caution and standby indicators
- Warm decorative lighting
Things to know
The line between yellow and amber is a matter of naming, so rely on the stated wavelength. Amber output also falls noticeably as the chip heats up, so power amber LEDs need good heat sinking.
REMEMBER
Colour is set by the semiconductor material, not by the plastic lens.Try it yourself
Sketch the circuit on paper first, calculate the values, then build it on a solderless breadboard using a low-voltage supply. Measure with a multimeter before you make anything permanent.
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