There's this white LED flashlight in my cellphone (a basic Nokia model). One fine day during power failure, i was flashing it about when I noticed that the streak of light it left in the darkness consisted of little line segments, in other words, the LED was switchin on and off at a very high rate.
Could anyone enlighten me as to why this PWM-kinda-drive for the LED is used in the phone?
Could anyone enlighten me as to why this PWM-kinda-drive for the LED is used in the phone?