PAGE 024 OF 150 · COLOURS, SIZES & TYPES
Ultraviolet LEDs
UV LEDs need eye and skin protection.
LED SYMBOLTriangle points from anode to cathode; the arrows show light leaving the part.
About UV LEDs
Ultraviolet LEDs emit light shorter than violet. Common UV-A types emit at 365 to 405 nm and need about 3.2 to 3.8 V.
Uses
- Making fluorescent materials glow
- Checking banknotes and security marks
- Curing resins and inks
Safety
UV can harm eyes and skin. Never look into the beam, avoid exposing skin for long, and wear UV-blocking glasses with strong sources. Shorter-wavelength UV-C LEDs are far more hazardous and are not suitable for casual projects.
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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