CLC Light Source Technology & LEDs 2

Question 1

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

Accepted Answer

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

Answer

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

Question 2

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

Accepted Answer

Constant current driver

Answer

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

Question 3

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

Accepted Answer

125–150°C

Answer

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

Question 4

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

Accepted Answer

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

Answer

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

Question 5

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

Accepted Answer

Violet pump with multi-phosphor blend

Answer

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.

(CLC) Certified Lighting Consultant Practice Test

(CLC) Certified Lighting Consultant Practice Test

CLC Light Source Technology & LEDs 2