How does current affect LED brightness?
When current flows through the diode in the forward direction, some of the electrical energy is converted into light of a specific color (i.e., wavelength). As the current through the LED increases, the brightness also increases. Typically, the recommended current for an LED is 20 milliamperes (mA) or less.
What is the relationship between the amount of current flowing through the LED and the brightness of the LED?
Allowing more current to flow through the LED will make it glow brighter but will also cause it to dissipate more heat. LEDs are designed to produce a set amount of light operating at a specific forward current ranging from about 10 to 20mA. In situations where power savings are important, less current may be possible.
What happens when the current of an LED is increased?
Firstly, human perception at constant power and variable duty cycle pulses. A say 10% duty cycle would result in 10 x the current at the same voltage for this to hold. Real LEDs will have somewhat higher forward voltages when current is increased by 10x but not greatly so. A fair test is probably Ipeak x time on = constant.
How can I change the brightness of my led?
You can also alter the brightness of an LED at a constant current by varying the duty cycle. A 50% reduction in the duty cycle is a 50% reduction in brightness.
How is the frequency of an LED driver determined?
The frequency of a switched LED driver is high enough that average power, not instantaneous power, should be used to determine maximum drive current. The limiting factor which determines maximum current at any duty cycle is average power dissipation.
Why are LEDs used for high power lighting?
High power LEDs used for lighting are pushing limits in a different way and exhibit more falloff with higher current. Maximum efficiency and maximum brightness are not the same thing. This difference is enough to matter in demanding applications. This is where you have to check the LED datasheet carefully.