how to dimm led light

[svizoman]

Hi guys.
I' ve bought **broken link removed**

and this **broken link removed**

I don't know how does this drivers work but I predict they control output voltage by PWM according to the input voltage (85-265V as written on the box).

Can I control the brightnes by regular dimmer switch which as I know use potentiometer and triac to cut AC sin wawe.

Would this work or would led flicker?

 

[chris.mourad]

Hi

Why do you talk about AC voltage? I am not sure LEDs should be driven by an alternating current. They just need DC current.

 

[FvM]

"Dimmable" LED power supplies are expected to work with regular triac dimmers. The LED brightness should be independent of AC input voltage, the power supply is sensing the dimmer phase angle. No idea how good it works, just try.

 

[jiripolivka]

LED dimmable drivers operate by PWM, pulse-width modulation not by AC cntrolled by a triac. You can make a simple LED dimmer by using a variable series resistor with a value exceeding that determining a maximum current. Reducing the current dims the LED output.
This method is not suitable for high-power LEDs as the power loss on the series resistor generates a lot of heat. Thus PWM is used for a better economy.

 

[FvM]

I see that it's not generally known what an AC dimmable LED power supply is and how it works. Please refer to manufacturers specification to get an idea. E.g.: https://www.meanwell.com/webapp/product/search.aspx?prod=PCD-16

In a brief, it translates the dimmer phase angle to switched mode supply variable output current.

 

[jiripolivka]

I see that it's not generally known what an AC dimmable LED power supply is and how it works. Please refer to manufacturers specification to get an idea. E.g.: https://www.meanwell.com/webapp/product/search.aspx?prod=PCD-16

In a brief, it translates the dimmer phase angle to switched mode supply variable output current.

Thanks for the info! Still no details are given in the spec.

 

[FvM]

Still no details are given in the spec.

Yes, I agree. But you get a basic idea what they are doing. Some points are unclear, e.g. obviously you can't have PFC operation and dimmer control at the same time.

You can also review datsheets of respective controller ICs, e.g. from NXP.
https://www.nxp.com/products/lighti...ics/ac_led_driver_ics_dimmable/SSL5231BT.html

 

[FlapJack]

Put this in Google images.

ac dimmable led power supply schematic

 

[svizoman]

I see only FvM undestood my question. I am not building a diimer and I am not runing LEDs with AC. I bouugt LED light (series of led chips of 10W & 24V) that comes with a led driver (85-265VAC input source). I also bought "dimmable" led driver for 10W leds and I intend to use it along with regular dimmer switch build around triac.

Since I don't know exactly how led drivers work, I predict they direct AC current and control brightness of leds by PWM but I have no idea of what shoud the iput source be.
Would it work with regular triac dimmer cutting the AC sin wave? Some dimmers have written that they work for loads of 40 to 300W in my case leds consume only 10W.

 

[FvM]

You'll notice that Meanwell shows a list of dimmers that has been tested with their product. In case of your cheap Ebay LED power supply, you hardly get that kind of information. So trial is the only way to find out.