Download to read offline
Uploaded byTaofir Shuvo
LED
This presentation introduces light emitting diodes (LEDs) and their uses. It explains that LEDs are semiconductors that emit light when electrically biased in the forward direction. The color of light depends on the energy level of electrons falling within the diode. Different types of LED displays are shown, including bar graphs and 7-segment displays. Applications discussed include uses in sensors, mobile devices, signs, automotive lights, general lighting, decorations, and laptop/TV screens.
LED
- 1.
- 2. Submitted to: Md. SayeedurRahman Lecturer in physics Submitted by : 171-23-4940 171-23-5013 171-23-4998 171-23-4984 171-23-5019 Section: C Dept. of TE
- 3.
- 4. • A lightemitting diode (LED) is essentially a PN junction opto-semiconductor that emits a monochromatic (single color) light when operated in a forward biased direction. • LEDs convert electrical energy into light energy.
- 5. LED: How ItWorks When current flows across a diode negative electrons move one way and positive holes move the other way. Therefore when a free electron falls it losses energy, the wholes exist at a lower energy level than the free electrons This energy is emitted in a form of a photon, which causes light. The color of the light is determined by the fall of the electron and hence energy level of the photon
- 6. Inside a LightEmitting Diode 1. Transparent Plastic Case 2. Terminal Pins 3. Diode
- 7. Some Types ofLED Bar graph 7-segment Starburst Dot matrix •There are some different types of LED. As for example we can see below:
- 8. Applications • Sensor Uses •Mobile Uses • Sign Uses • Automative Uses • Light Uses • Decoration Uses • Laptop & Smart TV Uses
- 9. Uses inUses inSensorSensor •LED are used for scanning barcode or QR code
- 10. Uses in Mobile •LEDare used smartphones for mobiles display
- 11. •LED is usedas Road signals & Cross- Signals
- 12. •LED is usedin automobiles headlight & back- light
- 13. •LED is usedin light bulbs, which gives very high quality light
- 14. •LED is usedfor latest technological Smart TV and laptops.
- 15. •LED is usedfor different types of home or outside decorations.
- 16. •LED is usedin multimedia projector.