If the LED drive circuit keeps constant current, the constant current source can be implemented. Why choose PWM to adjust the light? Does it have any unique advantages?
You want to know what the constant current source and the PWM are. Constant current source is stable in order to make the LED luminous, PWM pulse width modulation, it is not the purpose of stable, but to move light, is how to adjust LED luminous intensity has been. The purpose of the two is different, so it is not inconsistent. The advantage of PWM is that the active device of the circuit is on the switch state, the current is low when the current is high, the voltage is high and the current is small, so the power consumption is small and the circuit is efficient.
I don't already have a simple statement in front of you, right? "PWM circuit is the advantage of the active components in the switch state, the current low voltage and high voltage when the current is small, so small power consumption, high efficiency of the circuit." For example, by adjusting the current also can adjust the brightness, but it on the regulatory elements to create a larger power consumption, it is not cost-effective, but also to solve the problem of the fever, especially in the LED is high power type, it is more serious.
1, the PWM dimming ensures that the LED color index and the light color, This is also the advantage of PWM, and is convenient for digital signal control because the digital signal is as long as the level is low and the change is in the pulse width
Constant current is in order to ensure the normal order of the LED color rendering index does not change, PWM is in order to achieve the LED brightness adjustment, the purpose is not only ensure the LED color consistent under the condition of different brightness, color temperature is the same; One of the things to note is that leds vary in color temperature in different current situations. Do you understand
