Meanwell dimmable drivers.

[Ukreeferguy2020]

I have some Meanwell 700mA (LDD-700H) dimmable drivers and was wondering if anyone knew how they worked regarding dimming?

When one adjusts the dimmer channel via PWM for example, does the driver restrict the voltage going to the connected LEDs, and therefore dimming them, or does it restrict the current going to them and reducing their luminosity?

Basically... voltage or current?

Cheers. Steve.



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[mcgyvr]

Neither really..
It changes the duty cycle so its basically on for a period of time then off for a period of time and that repeats..
It does it fast enough though that your eye perceives it as dimmer..

Its always providing a fixed 700mA of current.. (LEDs need to be powered by a constant current source not constant voltage)..

 

[oreo57]

LDD output 50% duty cycle..

 

[Ukreeferguy2020]

Meanwell dimmable drivers.

I knew that you could dim an LED with pulse width modulation which alternates power on an off very quickly, but as the PWM signal goes to the driver, I thought it might finish by reducing the voltage instead. Thanks for the info.


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