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220-801 · Question #95

Older laptops that did not use LEDs used which of the following to power the backlight lamp?

The correct answer is B. Inverter. Older laptops used CCFL (Cold Cathode Fluorescent Lamp) backlights, which require alternating current (AC) to operate. Since laptops run on direct current (DC) from the battery or adapter, an inverter board is used to convert DC to the high-voltage AC needed to illuminate the…

Mobile devices

Question

Older laptops that did not use LEDs used which of the following to power the backlight lamp?

Options

  • ACathode
  • BInverter
  • CSolenoid
  • DPlasma

How the community answered

(67 responses)
  • A
    1% (1)
  • B
    94% (63)
  • C
    3% (2)
  • D
    1% (1)

Explanation

Older laptops used CCFL (Cold Cathode Fluorescent Lamp) backlights, which require alternating current (AC) to operate. Since laptops run on direct current (DC) from the battery or adapter, an inverter board is used to convert DC to the high-voltage AC needed to illuminate the CCFL tube. The cathode refers to the lamp component itself, not the power source. Modern LED-backlit screens do not require an inverter because LEDs operate directly on DC.

Topics

#laptop display#inverter#CCFL backlight#LCD

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