Practice Test Geeks(CLC) Certified Lighting Consultant Practice Test
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Light Source Technology & LEDs Flashcards

7 cards from real CLC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Light Source Technology & LEDs flashcards as text

  1. What does the term 'binning' refer to in LED manufacturing?

    Answer: Sorting LEDs by flux, color, and voltage into consistent groups

    Binning is the process of sorting LEDs into groups (bins) with similar photometric and electrical characteristics to ensure consistent product performance.

  2. Which LED driver topology is best suited for maintaining constant light output regardless of input voltage fluctuations?

    Answer: Constant current driver

    Constant current drivers regulate current through the LED, which directly controls light output, making them immune to input voltage variations.

  3. What is the typical junction temperature range that LED manufacturers specify as the maximum operating limit?

    Answer: 125–150°C

    Most LED manufacturers specify maximum junction temperatures between 125°C and 150°C; exceeding this accelerates lumen depreciation and reduces LED lifespan.

  4. An LED fixture rated at L70/B50 at 50,000 hours means:

    Answer: 50% of a sample will retain at least 70% of initial lumens at 50,000 hours

    L70 means 70% lumen maintenance; B50 means 50% of the tested sample population reaches that point at the stated hours.

  5. Which phosphor-converted white LED approach produces the broadest, most continuous spectrum?

    Answer: Violet pump with multi-phosphor blend

    A violet-pump LED with a multi-phosphor blend produces a fuller, more continuous spectrum with higher CRI than traditional blue-pump yellow-phosphor designs.

  6. What effect does increasing drive current beyond an LED's rated level have on efficacy?

    Answer: Efficacy decreases due to thermal droop and resistive losses

    Overdriving LEDs causes thermal droop and increased resistive losses in the semiconductor, reducing lumens-per-watt efficiency.

  7. In an LED COB (Chip-on-Board) package, what is the primary advantage over discrete SMD LEDs for the same luminous flux?

    Answer: Higher color consistency due to single phosphor layer over all chips

    COB packages apply a single phosphor layer over all chips, producing more uniform color and eliminating the 'multi-shadow' effect seen with discrete LEDs.