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#373013 - 25/08/2020 19:12 Can't dim enough
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12318
Loc: Sterling, VA
I have replaced as many of the lights in my house with LED bulbs as I can. There are two lamps that I purposefully have not swapped out, and those are the lamps we use as night lights for my kids. The incandescent bulbs are capable of dimming FAR more than any LED bulbs I've tried.

Why?

I understand how dimming has traditionally worked. I also understand the way that LED bulbs work around that technology. What I don't understand is why that limits the lower end dimming limit. Is it because they simply can't make the diodes put out that little light? Are they not able to separate them for individual control?

I recently had my son's bulb burn out and had to replace it with the only incandescent I had on hand. Are there any LED bulbs that can dim really far?
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Matt

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#373015 - 25/08/2020 19:42 Re: Can't dim enough [Re: Dignan]
Roger
carpal tunnel

Registered: 18/01/2000
Posts: 5680
Loc: London, UK
It's my understanding that LED dimming does it by using PWM (i.e. on for a bit, off for a bit, repeat). To dim, you reduce the number or length of "on" periods.

Once you go below a certain frequency, it becomes really noticeable as flickering. So they don't do that.
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#373016 - 25/08/2020 20:04 Re: Can't dim enough [Re: Dignan]
Phoenix42
veteran

Registered: 21/03/2002
Posts: 1424
Loc: MA but Irish born
Might this be a place where a smartbulb is needed? I'm assuming a smartbulb could dim further as it could shut off LEDs not just pulse them. Of course this means needing a smart switch or device to do the dimming.

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#373017 - 25/08/2020 23:51 Re: Can't dim enough [Re: Phoenix42]
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12318
Loc: Sterling, VA
That makes sense Roger. Sigh.

Originally Posted By: Phoenix42
Might this be a place where a smartbulb is needed? I'm assuming a smartbulb could dim further as it could shut off LEDs not just pulse them. Of course this means needing a smart switch or device to do the dimming.

Perhaps, though I have some Hue bulbs in my house and they're not much better, if at all. I have the lamps plugged into Lutron Caseta dimmers because Caseta is my favorite home automation product line of all time.
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Matt

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#373018 - 26/08/2020 13:00 Re: Can't dim enough [Re: Dignan]
tahir
pooh-bah

Registered: 27/02/2004
Posts: 1900
Loc: London
We never used nightlights, our kids didn't seem to mind. Dimming very low on LEDs is a problem, as Roger says if you get really low you can see noticeable flicker.

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#373019 - 26/08/2020 15:29 Re: Can't dim enough [Re: Dignan]
tanstaafl.
carpal tunnel

Registered: 08/07/1999
Posts: 5539
Loc: Ajijic, Mexico
If the night light is too bright, you might consider covering it with something that will only let a little of the light come through it. Even something as simple as aluminum foil with a couple of strategically placed pinholes might do the trick.
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"There Ain't No Such Thing As A Free Lunch"

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#373020 - 26/08/2020 18:22 Re: Can't dim enough [Re: tanstaafl.]
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12318
Loc: Sterling, VA
Originally Posted By: tahir
We never used nightlights, our kids didn't seem to mind. Dimming very low on LEDs is a problem, as Roger says if you get really low you can see noticeable flicker.

We tried really hard to get our son accustomed to no nightlight, but he wasn't having it. We never tried with our daughter.

Originally Posted By: tanstaafl.
If the night light is too bright, you might consider covering it with something that will only let a little of the light come through it. Even something as simple as aluminum foil with a couple of strategically placed pinholes might do the trick.

That would look pretty awful, as the nightlights are just their table lamps on their nightstand. We just use those because all the lights are automated and it's easy enough to do that. If I can't find a solution I'm probably just going to give in and use a more traditional night light that plugs into the wall.
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Matt

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#373021 - 26/08/2020 18:26 Re: Can't dim enough [Re: Dignan]
Tim
veteran

Registered: 25/04/2000
Posts: 1522
Loc: Arizona
Could you replace them with those blue glowing night lights? Something like this:

https://www.amazon.com/Elsent-Bright-Night-Light-Sensor/dp/B073M28VC9

<edit>Not replace the lamp, but the night light function. When the lamp is turned off, those night lights turn on due to the light sensor



Edited by Tim (27/08/2020 01:19)
Edit Reason: clariication

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#373022 - 27/08/2020 19:50 Re: Can't dim enough [Re: Tim]
canuckInOR
carpal tunnel

Registered: 13/02/2002
Posts: 3212
Loc: Portland, OR
Originally Posted By: Tim
Could you replace them with those blue glowing night lights?

Although, perhaps some other color than blue, because blue light during the evening/night has been linked to health issues.

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#373023 - 27/08/2020 20:40 Re: Can't dim enough [Re: Tim]
Dignan
carpal tunnel

Registered: 08/03/2000
Posts: 12318
Loc: Sterling, VA
Originally Posted By: Tim
Could you replace them with those blue glowing night lights? Something like this:

https://www.amazon.com/Elsent-Bright-Night-Light-Sensor/dp/B073M28VC9

<edit>Not replace the lamp, but the night light function. When the lamp is turned off, those night lights turn on due to the light sensor

Yeah, I mentioned that if I can't get this working I'll just use a more traditional plugin type of nightlight.

But I would get a light that was - at most - in the white spectrum. Blue would drive me nuts. We currently have these in the bathroom, where there's no lamps (naturally).

All LED bulbs in our home are the Philips "Warm Glow" LED variety, which actually shift to warmer color termperatures as they dim, much like incandescents do.

Our house is very much a sub-3000K space everywhere except my workshop. Even there, I had to try a few different work lamps before I found one that was as white as possible without any hint of blue.
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Matt

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