On 01/12/2023 20:15, alan_m wrote:
> On 01/12/2023 16:20, John Rumm wrote:
>
>> That is a known problem with some "active" switches that need to draw
>> power without the benefit of a neutral connection. However those don't
>> seem to cause a problem IME - and I have several, all driving LEDs and
>> have not seen an issue.
>
> It is a manufacturer's warning in the fitting instructions for that device.

The instructions say "Some LED lamps are not designed for electronic
dimmer switches and may remain illuminated even when a dimmer switch is
turned off."

To which I would suggest "don't use LED lamps not designed for
electronic dimming". However you can also fit one of these if it is a
problem:

https://www.tlc-direct.co.uk/Products/VLGF.html

Personally I have never found the need since all my dimmed LEDs seem to
work ok. (3 on remote controllable touch dimmers (one two way with
master slave dimmers), one on normal rotary push to switch dimmer. All
the dimmers are Varilight of various generations. Most of the lamp
fittings have multiple LEDs.

Also worth noting that some brands of bulb dim better than others -
either in dimming range and/or in controlling colour temperature.

--
Cheers,

John.

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On 29 Nov 2023 21:13:28 GMT, David wrote:
> Just realised that my original plan to replace the wall switch with a
> remote control switch has one major flaw.
> Most (single way) light switches are one wire in and one wire out.
> They just switch the live (I think) from the light fitting.
> As such current will only flow with the switch turned on.
> Remote control light switches seem to need live and neutral to the
> switch (not unreasonably).
> I was looking for a solution which didn't involve any rewiring.
> I don't fancy channelling out the wall and also lifting the floor in the
> loft to upgrade the wiring.

This should do what you want I think. Replace the wall switch with one of
these:
https://www.tlc-direct.co.uk/Products/QURS1W.html
(note "No neutral is required")

Then add extra wall switches:
https://www.tlc-direct.co.uk/Products/QUWS1W.html
or fobs:
https://www.tlc-direct.co.uk/Products/QUFB1.html

It doesn't do dimming, but meets all your other requirements.

There are dimming modules in the same series, but these do need a neutral.
You could install these next to the light, so you'd only need to lift one
board in the loft, or if you don't mind a box on the ceiling install it on
the ceiling next to the light.

Mike

On 01/12/2023 11:03, John Rumm wrote:
> On 29/11/2023 16:02, David wrote:
>> Contemplating a remote control light switch (possibly with dimmer) for the
>> bedroom so I don't have to get my lazy arse out of bed to work it.
>>
>> I see Screwfix list some which it claims work with Alexa, Google Home,
>> Androis App, IOS App.
>>
>> Does anyone have recommendations?
>>
>> I'm not keen on Alexa as it seems to listen all the time.
>> An Android App would be fine.
>
> How about:
>
> https://www.tlc-direct.co.uk/Products/VLIJDQI101S.html

Not sure I understand some of the info about that device:
"The dimmers also feature soft start to improve lamp life and totally
silent operation."

Does no "soft start" affect LED lamp life? Or perhaps it's dimmable CFLs
they're referring to, as it apparently can work with those according to
the dimmer selection info.

Also, on the downloadable datasheet, it states:
Operating Voltage: 230v 50Hz
Maximum Load Rating: LED; 100W (Max. 10 lamps)
Maximum Current Rating: 1.3A

Where does that current rating come from? At 230V, it's 300W, so why
the maximum load rating of 100W?

--

Jeff

On 03/12/2023 08:42, Jeff Layman wrote:
> On 01/12/2023 11:03, John Rumm wrote:
>> On 29/11/2023 16:02, David wrote:
>>> Contemplating a remote control light switch (possibly with dimmer)
>>> for the
>>> bedroom so I don't have to get my lazy arse out of bed to work it.
>>>
>>> I see Screwfix list some which it claims work with Alexa, Google Home,
>>> Androis App, IOS App.
>>>
>>> Does anyone have recommendations?
>>>
>>> I'm not keen on Alexa as it seems to listen all the time.
>>> An Android App would be fine.
>>
>> How about:
>>
>> https://www.tlc-direct.co.uk/Products/VLIJDQI101S.html
>
> Not sure I understand some of the info about that device:
> "The dimmers also feature soft start to improve lamp life and totally
> silent operation."
>
> Does no "soft start" affect LED lamp life? Or perhaps it's dimmable CFLs
> they're referring to, as it apparently can work with those according to
> the dimmer selection info.
>
> Also, on the downloadable datasheet, it states:
> Operating Voltage: 230v 50Hz
> Maximum Load Rating: LED; 100W (Max. 10 lamps)
> Maximum Current Rating: 1.3A
>
> Where does that current rating come from?  At 230V, it's 300W, so why
> the maximum load rating of 100W?
>

Power factor. So whilst they take a what seems a high current for the
power used, they only do so for a small part of a mains cycle, so the
power consumed is small. This is the difference between VA and Watts.

if you are interested just stick

"whats the difference between VA and watts"

into your normal search engine, you will find lots of artivles.

Dave

On 2023-12-03, Jeff Layman <Jeff@invalid.invalid> wrote:
> On 01/12/2023 11:03, John Rumm wrote:
> Also, on the downloadable datasheet, it states:
> Operating Voltage: 230v 50Hz
> Maximum Load Rating: LED; 100W (Max. 10 lamps)
> Maximum Current Rating: 1.3A
>
> Where does that current rating come from? At 230V, it's 300W, so why
> the maximum load rating of 100W?
>

I liked the bit about "not for sale to Germany". Is the war not finally
over. :)

(Yes, it is about commercial agreements, but still:) )

--
greymausg@mail.com
Death to the Influencers, hung, drawn and quartered is more than they deserve.
BringBack(Bonking)Boris..

On 12/3/2023 7:12 AM, David Wade wrote:
> On 03/12/2023 08:42, Jeff Layman wrote:
>> On 01/12/2023 11:03, John Rumm wrote:
>>> On 29/11/2023 16:02, David wrote:
>>>> Contemplating a remote control light switch (possibly with dimmer) for the
>>>> bedroom so I don't have to get my lazy arse out of bed to work it.
>>>>
>>>> I see Screwfix list some which it claims work with Alexa, Google Home,
>>>> Androis App, IOS App.
>>>>
>>>> Does anyone have recommendations?
>>>>
>>>> I'm not keen on Alexa as it seems to listen all the time.
>>>> An Android App would be fine.
>>>
>>> How about:
>>>
>>> https://www.tlc-direct.co.uk/Products/VLIJDQI101S.html
>>
>> Not sure I understand some of the info about that device:
>> "The dimmers also feature soft start to improve lamp life and totally silent operation."
>>
>> Does no "soft start" affect LED lamp life? Or perhaps it's dimmable CFLs they're referring to, as it apparently can work with those according to the dimmer selection info.
>>
>> Also, on the downloadable datasheet, it states:
>> Operating Voltage: 230v 50Hz
>> Maximum Load Rating: LED; 100W (Max. 10 lamps)
>> Maximum Current Rating: 1.3A
>>
>> Where does that current rating come from?  At 230V, it's 300W, so why the maximum load rating of 100W?
>>
>
> Power factor. So whilst they take a what seems a high current for the power used, they only do so for a small part of a mains cycle, so the power consumed is small. This is the difference between VA and Watts.
>
> if you are interested just stick
>
> "whats the difference between VA and watts"
>
> into your normal search engine, you will find lots of artivles.
>
>
>
> Dave

Some effort was made to do PFC (Power Factor Correction)
on the earlier (more expensive) LED lamps.

The cheap ones now, the power factor is more consistent
with a raw SMPS. I guess with no factors to control implementation,
this is what we get.

PFC LED lamp (more likely sold years ago)

https://www.researchgate.net/figure/Experimental-results-Steady-state-performance-for-LED-lamp-driver-using-the-proposed-PFC_fig8_260030758

Plain LED lamp (what you can expect today)

https://www.researchgate.net/figure/Voltage-and-current-waveforms-for-the-LED-lamp_fig12_333790025

The specs for the lamps we can buy at the store now,
they have a "cycle count limit" for lifespan, in addition
to the normal termination-of-life due to drop in intensity.

I had one of those cheap LEDs fail after only a few months,
putting me well short of "10,000 hours", and I'm pretty sure the
number of start cycles didn't kill it either. The more expensive
LEDs in past years, had a 25,000 hour rating (based on expiry
due to LED intensity dropping, and the bulb still kinda works).

Paul

On 03/12/2023 08:42, Jeff Layman wrote:
> On 01/12/2023 11:03, John Rumm wrote:
>> On 29/11/2023 16:02, David wrote:
>>> Contemplating a remote control light switch (possibly with dimmer)
>>> for the
>>> bedroom so I don't have to get my lazy arse out of bed to work it.
>>>
>>> I see Screwfix list some which it claims work with Alexa, Google Home,
>>> Androis App, IOS App.
>>>
>>> Does anyone have recommendations?
>>>
>>> I'm not keen on Alexa as it seems to listen all the time.
>>> An Android App would be fine.
>>
>> How about:
>>
>> https://www.tlc-direct.co.uk/Products/VLIJDQI101S.html
>
> Not sure I understand some of the info about that device:
> "The dimmers also feature soft start to improve lamp life and totally
> silent operation."
>
> Does no "soft start" affect LED lamp life? Or perhaps it's dimmable CFLs
> they're referring to, as it apparently can work with those according to
> the dimmer selection info.

Soft start was more of benefit for halogen lamps longevity. There might
be some aesthetic benefit from the softer start on LED but it will
probably not make any difference to life.

>
> Also, on the downloadable datasheet, it states:
> Operating Voltage: 230v 50Hz
> Maximum Load Rating: LED; 100W (Max. 10 lamps)
> Maximum Current Rating: 1.3A
>
> Where does that current rating come from?  At 230V, it's 300W, so why
> the maximum load rating of 100W?

LEDs will present a reactive load, due to a combination of being
capacitive, and also having a non sinusoidal current draw (i.e. they
draw their current in short gulps near the centre of the peak of the
mains waveform). So the real power in watts will be significantly lower
than the apparent power you see in peak current draw multiplied by RMS
voltage.

See the section on switched mode supplies:

https://wiki.diyfaq.org.uk/index.php/Power_factor#Other_causes_of_low_power_factor

--
Cheers,

John.

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| John Rumm - john(at)internode(dot)co(dot)uk |
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