Think you know LEDs? Test your skills on our Designing with LEDs trivia contest. Submit your answers to these five questions and you will be entered to win one of five Solar-Powered LED Flashlights!


QUESTION 1
The luminous flux and dominant wavelength (or color temperature for white LEDs) of LED light are controlled by:
The drive circuit’s output capacitor
The EMI around the lighting system
The drive circuit’s input voltage
The average forward LED current

QUESTION 2
LED manufacturers generally recommend a ripple current of::
+/-5% to +-20%
+/-10% to +-35%
+/-5% to +-40%
Ripple current is inconsequential in LED lighting designs

QUESTION 3
Ripple from the drive circuit is not visible to the human eye over the typical switching regulator frequency range of:
50 Hz – 1 kHz
50 Khz to 2 MHz
800 kHz to 1.6 MHz
1 MHz to 2 Mhz

QUESTION 4
Which LED driver switching topology should be used if the input voltage always exceeds the sum of the maximum forward voltages of every LED in a string?
Buck
Boost
Buck-boost
None of the above

QUESTION 5
Which LED driver switching topology should be used when the sum of the minimum forward voltage of all the LEDs in a string will always exceed the maximum input voltage?
Buck
Boost
Buck-boost
None of the above