dimmable LED flicker -trick

[Harry Bloomfield]

Months ago, I bought some new dimmers, to replace some decades old ones, which caused the brighter dimmable LED's I had fitted, to flicker. The old dimmers had worked fine, with the first set of LED lamps, but the lamps needed to be brighter.

On fitting brighter dimmable LED's, the flicker problems began. The new dimmers were described as supposed to be able to auto select the correct positive or negative trigger. Despite the new dimmers and the dimmable LED's, I still sometimes notice an occasional, very brief flicker.

What I have since found a workaround - if I set the light level I want on the dimmer, then turn off for a few seconds and back on, at the new setting - there is no more flicker.

 

[ericmark]

I wish I could say what causes the shimmer one sees on some LED's, my electronic switches click, so one assumes they had a relay inside, they do not dim, most bulbs work OK, however the G9 bulbs caused me a problem, the small bulb I had a problem with staying on cured with one of these and a shimmer which would go if a quartz bulb was fitted, only one of 5 needed to be quartz or one of the larger bulbs were fitted.

One of the larger bulbs failed, and I opened it to see what was inside, the smoothing capacitor after the full wave rectifier was nearly as big as the smaller bulb, actually found a dry joint and repaired the bulb, still working a year latter.

But there is no good explanation why one bulb should stop the flicker with the others, but it did. The switch states minimum bulb size, and has a chart to say which bulbs should work, however the 2.3 watt Philips bulb did not work without flicker, it states up to 5-6 bulbs a circuit, total not to exceed 250 watt, (50 watt LED) I am sure I did read some where 5 watt minimum.

I had 5 fitted, but due to problems with lights doing daft things, now down the 2, had them around 4 years, and main good point is it works with a remote even with no internet, it needs a hub to connect to internet, but not to the remote, and can have 4 remote's paired to one switch. I use them as no two way switching in the bedrooms.

It only has 3 time slots as standard, and you can select which days of the week they work on, plus IFTTT if you do need extra slots.

However the Lidi bulbs could also work with a remote, and these can dim as well as On/Off, and you can also adjust the colour temperature with the app, and were cheaper, unfortunately can't find more of the Lidi remotes, the came with the three lamp GU10 light bar, and work with zigbee.

In the guest bedroom I use a bulb with dedicated remote which does not connect to internet, it means no need to program it into guests phone, default is on, so turn off light at wall switch and back on, and it works even without the remote. From B&M bargains.

The landing light odd one out, and uses a relay this means original switch still works like a two way switch with phone or google nest mini control. Although I can dim and colour change the centre bulb, in the main centre bulb used so it does not wake anyone, and outers for good light it is not really there because of functionality, but to look good. I think we have to decide if we want lights to look good, or light the room, I can dim many of my lights, but not really to do with functionality, and most are zigbee controlled with SmartLife. Or voice control with Nest Mini's, but most rooms amount of light is adjusted number of lights switched on, not a dimmer switch, we did start fitting them in the 80's but it was a passing fad.

 

[Harry Bloomfield]

I wish I could say what causes the shimmer one sees on some LED's, my electronic switches click, so one assumes they had a relay inside, they do not dim, most

My dimmer issue, wasn't a shimmer - rather it was an irregular and very brief, off then back on, several seconds to several minutes between them. So very brief, as at first to leave me wondering if it was maybe my blinking. None-the-less, quite annoying and distracting.

 

[JohnW2]

I wish I could say what causes the shimmer one sees on some LED's, my electronic switches click, so one assumes they had a relay inside, they do not dim, most bulbs work OK, however the G9 bulbs caused me a problem, the small bulb I had a problem with staying on cured with one of these ....

LED lighting with good old-fashioned ('mechanical') switches works fine

As for anything else, it really depends how much time, effort, heartache and cost you are willing to expend in the name of so-called "progress"

Kind Regards, John

 

[Harry Bloomfield]

LED lighting with good old-fashioned ('mechanical') switches works fine

Yes, but sometimes dimmable lighting can be more suitable, or effective. My living room has a 22w CFL, handy for 'doing things' which needs lots of good general illumination. That is supplemented by 2x 8w + 1x 8w wall lights on dimmers, providing localised lighting, enough for reasonably close work, but they can be set down to TV viewing light levels, or anything between. Match the lighting level, precisely to the needs.

 

[Loofah]

My sparky fitted dimmers and LED downlights throughout when we did a renovation. Some rooms have been ok, others have had flickering and I'm now just swapping to basic switches as it's too much of a PITA. We have so many lighting circuits that we just switch less on for 'moody' lighting instead of dimming. Works for us

 

[JohnW2]

Yes, but sometimes dimmable lighting can be more suitable, or effective. My living room has a 22w CFL, handy for 'doing things' which needs lots of good general illumination. That is supplemented by 2x 8w + 1x 8w wall lights on dimmers, providing localised lighting, enough for reasonably close work, but they can be set down to TV viewing light levels, or anything between. Match the lighting level, precisely to the needs.

All true - and I suppose my comment was more related to 'electronic switches' (and other new-fangled gizmos) of one sort or another, rather than dimmers.

As far as "matching lighting level to needs", I have to say that, even though it might be a little 'naughty' (in terms of PF), given my fairly unhappy experiences with dimming LEDs, in several places in my house I have changed the single-gang switches to two or three gang ones, and use them to switch capacitors in series with the LED - thereby achieving two or three levels of light intensity without any 'electronics'.

Kind Regards, John

 

[Harry Bloomfield]

All true - and I suppose my comment was more related to 'electronic switches' (and other new-fangled gizmos) of one sort or another, rather than dimmers.

I agree. I don't like too much complexity, too much to go wrong. My upper limit is dimmers wall switches, and smart plug adaptors, which are easy to simply unplug to bypass, when they inevitably 'go wrong'.

As far as "matching lighting level to needs", I have to say that, even though it might be a little 'naughty' (in terms of PF), given my fairly unhappy experiences with dimming LEDs, in several places in my house I have changed the single-gang switches to two or three gang ones, and use them to switch capacitors in series with the LED - thereby achieving two or three levels of light intensity without any 'electronics'.

Two or three levels is generally enough for most purposes, and maybe better in many ways - because I often find myself adjusting the level up or down a bit, when I get it wrong on the dial.

 

[ericmark]

I have not had any problems with dimming bulbs, I select the bulb in the Smartlife app, and adjust light output or colours, or used the remote which came with the bulb.

It is my attempts to do it on the cheap which have caused problems, 8 x 6 watt E14 candle bulbs are expensive if you want them as smart bulbs, so the wall switch is a cheap option, clearly doing it on the cheap, we buy cheap switches.

 

[JohnW2]

I agree. I don't like too much complexity, too much to go wrong. My upper limit is dimmers wall switches, and smart plug adaptors, which are easy to simply unplug to bypass, when they inevitably 'go wrong'.

I agree - although, as said, I've gone one step further and essentially abandoned dimmers.

Two or three levels is generally enough for most purposes, and maybe better in many ways - because I often find myself adjusting the level up or down a bit, when I get it wrong on the dial.

Indeed. I do as I described, and never really find the need for more than the three levels it can provide - in many situations, two is really enough.

Kind Regards, John

 

[bernardgreen]

Connecting two matching tungsten lamps in series is the almost perfect way to achieve a warm inviting dimmed light,

 

[Harry Bloomfield]

Connecting two matching tungsten lamps in series is the almost perfect way to achieve a warm inviting dimmed light,

Not very energy efficient these days though, and efficiency goes down drastically as the voltage across a tungsten lamp reduces.

 

[JohnW2]

Connecting two matching tungsten lamps in series is the almost perfect way to achieve a warm inviting dimmed light,

Yes, if one likes 'red light' than that is a solution - but, as Harry has said, probably not a very energy-efficient one(and increasingly difficult to implement, as incandescent bulbs gradually disappear).

My approach with LEDs and switched capacitors works fine, without any significant change in colour of light.

Kind Regards, John

 

[bernardgreen]

Yes, if one likes 'red light' than that is a solution

It is more of a warm orange colour than red

as Harry has said, probably not a very energy-efficient one

Power to light, poor efficiency
Power to non wasted heat, 100 percent efficient
Power to comfort, high efficiency.

 

[JohnW2]

It is more of a warm orange colour than red

OK - but certainly more red than blue!

Power to light, poor efficiency

Indeed. I presume that's what Harry was referring to.

Power to non wasted heat, 100 percent efficient

Only when heat is needed - otherwise 0% efficient.

Power to comfort, high efficiency.

That's obviously a very personal thing. I agree that one cannot perfectly reproduce the spectrum of a dimmed incandescent with an LED, and that you prefer the former. but there's a fairly wide range of LED 'colours' available, and most people seem to be satisfied by at least one of them.

Kind Regards, John