- #1
JC2000
- 186
- 16
- TL;DR Summary
- If I have understood correctly, the duty cycle of a pulse signal can be used to control the brightness of an LED. I am unsure as to why this happens.
The brightness of an LED is a result of the current passing through it. The current is a function of the voltage across the LED.
The duty cycle represents the percentage of the time period that the signal is in the ON state ( which means that the voltage is at max value as compared to 0 V for the rest of the time period).
If I have understood correctly, it seems that the duty cycle can be increased to make the LED brighter?!
I don't see why this should happen given that at the end of the day the voltage across the LED is constant irrespective of the duty cycle.
The explanation seems to be that the effective voltage is what causes the LED to change brightness (Effective/ Average Voltage = Duty Cycle * Maximum Voltage). However I am unable to see why this should be so given that actually the max voltage is always being applied in reality.
The duty cycle represents the percentage of the time period that the signal is in the ON state ( which means that the voltage is at max value as compared to 0 V for the rest of the time period).
If I have understood correctly, it seems that the duty cycle can be increased to make the LED brighter?!
I don't see why this should happen given that at the end of the day the voltage across the LED is constant irrespective of the duty cycle.
The explanation seems to be that the effective voltage is what causes the LED to change brightness (Effective/ Average Voltage = Duty Cycle * Maximum Voltage). However I am unable to see why this should be so given that actually the max voltage is always being applied in reality.