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Dimmable led drivers?

Harald Kapp

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How do dimmable LED drivers work?
This kind of dimmable LED driver is meant to be used with a classic dimmer/switch combo used to control brightness of lamps. The featiure "dimmable" needs to be mentioned since not every LED driver will work with this kind of dimmer.
For setting the brightness on the low voltage side via potentiometer or similar typically a technique called PWM is used. You can buy off the shelf modules for that purpose.
 

primuspaul

Feb 7, 2018
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This kind of dimmable LED driver is meant to be used with a classic dimmer/switch combo used to control brightness of lamps. The featiure "dimmable" needs to be mentioned since not every LED driver will work with this kind of dimmer.
For setting the brightness on the low voltage side via potentiometer or similar typically a technique called PWM is used. You can buy off the shelf modules for that purpose.
What if I want to use the dimming module to permanently dim the LED? Do I need a resistor on live 120VAC wire? Is there a cheap way to do it without generating waste heat?
 
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Harald Kapp

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Do I need a resistor on live 120VAC wire? Is there a cheap way to do it without generating waste heat?
A resistor is a cheap way to generate as much waste heat as possible.
Use one of the PWM modules I linked.
 

Sunnysky

Jul 15, 2016
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This LED driver is NOT meant to be dimmable without issues. It provides a CC output of 300mA +/-3% with TOO WIDE an input range for triac dimming to be practical. max/min =265Vac / 85Vac is 3.4x ratio so the output will track and stay constant over this RMS voltage ratio. So when you want to dim it with an input < 85V it will start saturating the buck coil with more current and it will start making noises (buzz) try to put out max current with low input voltage. Remember it was design to put out constant current,. SO bad choice for a dimmer. upload_2018-3-14_15-47-8.png
 

Bluejets

Oct 5, 2014
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Note that there are many types of lamp dimmers and most are for a specific purpose and as such most will not work correctly with LED dimmable drivers.
 
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