Highest speed for normal LEDs

[MahmoudHassan]

Hi All
wish you the best
I am planning to work in circuit that will switch output across normal LED , but I am confused about the highest speed the LED can work at so that my eye can detect change in light emitted by the LED ?

Thanks a lot , your help is really appreciated

Best Regards,
Mahmoud

 

[dick_freebird]

The LED, any LED, will be way way way faster than your human
persistence-of-vision. You can't really make out 120Hz flicker.
LEDs can follow hundreds of MHz to multi-GHz depending on
type and so on.

It's not a LED problem.

 

[Audioguru]

Pulse Width Modulation (PWM) is used to dim an LED. If the duration of flashes is less than 30ms then the LED will appear dimmer.

 

[Vbase]

Mahmoud,
audioguru probably means that if a LED is switched on for a single pulse of 30ms or longer you will be able to see it, I agree with that.

Pulse Width Modulation (PWM) is used to dim an LED. If the duration of flashes is less than 30ms then the LED will appear dimmer.

audioguru, this will be a good test to do on a simulator.

 

[Audioguru]

Mahmoud,
audioguru probably means that if a LED is switched on for a single pulse of 30ms or longer you will be able to see it, I agree with that.
audioguru, this will be a good test to do on a simulator.

It is a standard dimmer system. It is also used for DC motor speed control.

 

[MahmoudHassan]

Thanks a lot really helpful for me
Thanks a lot
God bless your efforts
really appreciated