Humming led light with dimmer

LEDs are driven by controllers, usually constant current and are designed to respond little to input voltage differences. Changing the input voltage will only change the input current and nothing on the output.

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Rick C

I installed a ceiling fan in a restaurant once. I found it had a "demo" mode where it would blink the lights, run the fan up and down and play a melody. lol I have no idea why they would include a sounder in a fan.

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Rick C

This is a $3000 light in a $2M house. They just like fancy stuffs. It does not have to make sense. For the moment, we might shut off the on board led and perhaps shine external lights on it.

Are the LEDs scattered in the fixture? Do you know anything about the controller or how the LEDs are wired? How many watts?

I have an LED controller module that uses a particular chip. There is a pin compatible controller chip that provides dimming. I am pretty sure all I need to do is swap out the controller and wire a 0-x volt dimming control. It's rated for 50 watts. I need to get the chips on order.

You could put a controller in the wall box and run the LED lines to the chandelier. A switching controller can run pretty cool so it may not need any air flow. Spot lights should work well as long as you don't aim them into people's eyes? Is there an upstairs balcony?

There is a multi-million dollar house on the lake here. They have a gazebo which stands on pilings a bit off the shore. It has a couple of spot lights shining on it from the shore. They are aimed right in your eyes when on the lake at night. Very sad.

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Rick C

t.

Firstly 'constant current' circuits are in fact current limited circuits. 2 nd the series capacitor reduces current - the only way a basic current cont rol psu can respond is to put out too little current. It works with simple sm psus & CR psus. There might be controllers out there that shut down inst ead, but I've not met them.

Why does Phil think series reactance can't work? Don't tempt me. Let's just say he hasn't tried it. I have.

NT

I'm sure silence is an important feature to mimes.

--sp

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Best regards,  
Spehro Pefhany

The OP most likely has a triac dimmer. Varying the phase angle the power is on does nothing to reduce the current in a current regulated circuit running from filtered DC. What it can do is exactly what you say you haven't seen, cutting the power off altogether. That's what happens with mine.

I think he is saying the dimmer actually works, but the light makes a bunch of noise, so I guess he has something different than what I have.

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Rick C

tput.

s. 2nd the series capacitor reduces current - the only way a basic current control psu can respond is to put out too little current. It works with sim ple sm psus & CR psus. There might be controllers out there that shut down instead, but I've not met them.

just say he hasn't tried it. I have.

correct. My comments were regarding series C, not triac dimers

I said that hasn't happened with C dimming. Triac dimming is a different an imal.

NT

** Did you look u[o the device the OP posted about?

I did and the maker claims it is well suited to use with dimmable LEDs lights. It also warns that such lights may "hum or buzz".

More likely the unit uses a mosfet output stage acting as a trailing edge dimmer. Many LED lights have circuits that react the off time and reduce the current accordingly.

The fact the OP's LED light does dim suggest this is the case.

.... Phil

Somewhere in the lamp or its power brick is a box with a ratings sticker. You need to find it (or they, there may be more than one) is, and get the manufacturer's data.

Lots of dimmable fixtures, with different (incompatible) electronics. Leviton, for instance, has an LED fixture line, using ballasts, that takes a low-voltage dimmer auxiliary control.

Have you thought about using a isolated transformer?

drive the primary with the dimmer, secondary to the light.

Jamie

If we have to open up the light mounting box to fix it, the answer is going to be no. But it's hard to fit a transformer into the light switch also.

Anyway, transformer might change the way the dimmer works. At least, not the same linear range.

I was puzzled how putting a transformer in the way might resolve it. It would need to be a very heavy transformer anyway.

NT

With that kind of wattage rating it almost certainly is not for LEDs.

** Why not look up the unit's details before posting shit like that ?

You colossal moron.

.... Phil

The manufacturer says it *can* be used for LEDs, which doesn't mean it works all that well.

** Yes it does and the power rating does NOT tell you a damn thing.

One dimmer can run DOZENS of lights -

GET IT, Fuckhead ?????

.... Phil

150W is a LOT of LED for a residential application. Now maybe if you're talking about a BIG parking lot or something...

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... (you made your point, no need for me to repeat it)

150W is not that much. Some kitchen and dinning rooms have 10s of bulbs. They adds up quickly. In this instance case, it's a single chandelier with reflective lighting. So, they want it very bright at time, but dimming most other time.

We didn't anticipate so much trouble with LED light controller. Next time, we will just get the incandescent version and change to LED bulbs. They might not be as efficient as build-in unit, but they can be changed.