LED Dimmer switch or fixed brightness reduction

Thread Starter

RodneyB

Joined Apr 28, 2012
697
I have installed 6 x 4 Watt 220 Volt LED lights. A dimmer switch in Zimbabwe is US$275.00 which is Just outrageous.

I am trying to see if there is a way that I can use a incandecent lamp dimmer modified somehow on these lamps.

Alternativly I dont need them completely dimmed, just the intensity reduced, is there something fixed that I can do to achieve this.

Many thanks

Rodney
 

Dodgydave

Joined Jun 22, 2012
10,063
Yes it should work on leds no problem , a dimmer just alters the voltage across the leds,.

You might find the led bulbs have a Capacitor as a current limiter and series resistors too.
 

Thread Starter

RodneyB

Joined Apr 28, 2012
697
Yes it should work on leds no problem , a dimmer just alters the voltage across the leds,.

You might find the led bulbs have a Capacitor as a current limiter and series resistors too.
Thank you, All the articles I have read say that you have to use a special LED dimmer switch and on the incandescent lamp dimmeres it says not suitable for LED lights

So was just needing conformation
 

Dodgydave

Joined Jun 22, 2012
10,063
As Leds are current driven, they are usually controlled by a Constant Current Dimmer, you can use Voltage control with series resistors just as well, but it won't be as smooth at low lighting.
 

Tonyr1084

Joined Sep 24, 2015
6,372
All the articles I have read say that you have to use a special LED dimmer switch and on the incandescent lamp dimmeres it says not suitable for LED lights
I use regular dimmers all the time. BUT: If I use a regular dimmer without an incandescent load the LED's can flash annoyingly and self destructively. But by adding a single incandescent bulb the whole thing dims nicely. Been doing that for many years.
 

Thread Starter

RodneyB

Joined Apr 28, 2012
697
I use regular dimmers all the time. BUT: If I use a regular dimmer without an incandescent load the LED's can flash annoyingly and self destructively. But by adding a single incandescent bulb the whole thing dims nicely. Been doing that for many years.
Thank you very much, I am going to try this
 

MisterBill2

Joined Jan 23, 2018
9,529
I have installed 6 x 4 Watt 220 Volt LED lights. A dimmer switch in Zimbabwe is US$275.00 which is Just outrageous.

I am trying to see if there is a way that I can use a incandecent lamp dimmer modified somehow on these lamps.

Alternativly I dont need them completely dimmed, just the intensity reduced, is there something fixed that I can do to achieve this.

Many thanks

Rodney
If the LED devices are listed as dimable then you should be able to reduce the brightness with the dimmer that you have. It may work even better if you also put a single incandescent bulb in parallel with the LED devices. Sometimes that helps a lot.
 

MisterBill2

Joined Jan 23, 2018
9,529
@MisterBill2 See post #5 Beat you to it almost 12 hours. ")
I am neither infallible nor invincible, not since mid 1969. So I occasionally miss things like that. But perhaps getting the same answer from two independent sources will add to it's credibility.
What I am not sure about is if some of the non- dimable LED devices will be destroyed by connecting to a dimmer the way that some CFL devices will be destroyed. The failure of the one CFL was quite spectacular.
 

Tonyr1084

Joined Sep 24, 2015
6,372
@MisterBill2 I'm considering making a very short video of my LED's that dim with regular dimmers AND one set of LED's that - without the incandescent - flash incessantly. Maybe tomorrow.

As for repeating something someone else already covered - I'm notorious for doing that. But why since 1969?
 

MisterBill2

Joined Jan 23, 2018
9,529
@MisterBill2 I'm considering making a very short video of my LED's that dim with regular dimmers AND one set of LED's that - without the incandescent - flash incessantly. Maybe tomorrow.

As for repeating something someone else already covered - I'm notorious for doing that. But why since 1969?
Now you have an interesting LED activity. I recently had to replace some 48 inch LED tube lights. They would begin their failure mode by flashing, first one set and then all 96 LEDs, and then go out completely. When I open the tubes I find that one or 2 leds in each series group of 32 does not light when I apply 2.8 volts across it.That is as far as I have gone. These are T8 sized 48 inch devices that take 120 volts AC, mains direct, from end to end.The back half is an aluminum heat sink for the LED devices, which I suspect is not adequately in contact with the LED circuit board. But since as the failure progresses only one section flashes while the others stay lighted it seems that the failure is not in the power supply section. But possibly that is wrong. Do LEDs ever fail in a flashing mode????
I probably should post this in a new thread, I suppose.
 

Tonyr1084

Joined Sep 24, 2015
6,372
As promised, here's a short video of dimming LED lamps with an incandescent lamp in the circuit. And don't blast me for using the word "dimmnes". I know it's not a word, but I couldn't think of what to say. After all, this was unscripted.

 

MisterBill2

Joined Jan 23, 2018
9,529
Hey Tony, "Dimness is a perfectly good word, found in classical literature. I see far worse in posts here on most days. Today I had to switch on my light because of the dimness due to the storm clouds.
 
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