• Re: light dimmer leading/trailing edge

    From Andy Burns@21:1/5 to All on Tue Dec 24 12:33:28 2024
    alan_m wrote:

    I've just installed a new light fitting with dimmable LED bulbs and it's connected to an existing light dimming switch.

    The bulbs don't dim at all, just stay at full brightness.

    Is this the expected behaviour of a bulb that requires trailing edge
    dimming but is connected to a leading edge dimmer switch or should I
    expect some form of step dimming or flickering?

    Previously the dimmer worked with the LED bulb fitted in the old light fitting but this new one only takes the smaller E14 bulbs where there
    seems less choice for the dimmable versions.

    The easiest option for me would be to possibly fit a trailing edge
    dimmer switch rather than try and find a working bulb to work with the existing switch.
    I've had better success with the v-Pro dimmers, than MK LED-specific
    dimmers (flickery) the v-pro can be 'programmed' to different modes to
    suit the lamps.

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  • From alan_m@21:1/5 to All on Tue Dec 24 12:16:00 2024
    I've just installed a new light fitting with dimmable LED bulbs and it's connected to an existing light dimming switch.

    The bulbs don't dim at all, just stay at full brightness.

    Is this the expected behaviour of a bulb that requires trailing edge
    dimming but is connected to a leading edge dimmer switch or should I
    expect some form of step dimming or flickering?

    Previously the dimmer worked with the LED bulb fitted in the old light
    fitting but this new one only takes the smaller E14 bulbs where there
    seems less choice for the dimmable versions.

    The easiest option for me would be to possibly fit a trailing edge
    dimmer switch rather than try and find a working bulb to work with the
    existing switch.

    --
    mailto : news {at} admac {dot} myzen {dot} co {dot} uk

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  • From Theo@21:1/5 to Andy Burns on Tue Dec 24 13:24:52 2024
    Andy Burns <usenet@andyburns.uk> wrote:
    alan_m wrote:

    I've just installed a new light fitting with dimmable LED bulbs and it's connected to an existing light dimming switch.

    The bulbs don't dim at all, just stay at full brightness.

    Is this the expected behaviour of a bulb that requires trailing edge dimming but is connected to a leading edge dimmer switch or should I
    expect some form of step dimming or flickering?

    Previously the dimmer worked with the LED bulb fitted in the old light fitting but this new one only takes the smaller E14 bulbs where there
    seems less choice for the dimmable versions.

    The easiest option for me would be to possibly fit a trailing edge
    dimmer switch rather than try and find a working bulb to work with the existing switch.
    I've had better success with the v-Pro dimmers, than MK LED-specific
    dimmers (flickery) the v-pro can be 'programmed' to different modes to
    suit the lamps.

    +1. Basically dimmable LEDs are a hack. The LED driver notices the mangled mains waveform from the dimmer and works out how much to dim the LED. If
    the mains waveform doesn't match what the bulb is expecting it won't dim,
    and cheaper LEDs won't have enough energy storage to keep going through a
    mains cycle and may flicker.

    So when you change the lamps you need to set the dimmer to something they expect. Different modes on the dimmer can be helpful here.

    Another option is to fit one halogen bulb in the fitting which gives a more continuous current waveform through the whole cycle. I have a V-Pro dimmer with some dimmable GU10s and without that they flicker at low dim settings.

    Theo

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  • From Brian@21:1/5 to junk@admac.myzen.co.uk on Tue Dec 24 20:45:48 2024
    alan_m <junk@admac.myzen.co.uk> wrote:

    I've just installed a new light fitting with dimmable LED bulbs and it's connected to an existing light dimming switch.

    The bulbs don't dim at all, just stay at full brightness.

    Is this the expected behaviour of a bulb that requires trailing edge
    dimming but is connected to a leading edge dimmer switch or should I
    expect some form of step dimming or flickering?

    Previously the dimmer worked with the LED bulb fitted in the old light fitting but this new one only takes the smaller E14 bulbs where there
    seems less choice for the dimmable versions.

    The easiest option for me would be to possibly fit a trailing edge
    dimmer switch rather than try and find a working bulb to work with the existing switch.


    In general, trailing edge dimmers are recommended for LED bulbs but some
    are fine with leading edge ones. The LE dimmers were fitted ( about) 1998
    so long before LED bulbs were around.

    We used LE ones with some LED bulbs - IKEA large globes ( I think 120W equivalent) and 3 40W equivalents in wall lights without issues in two
    rooms. ( We originally used ordinary bulbs - I fitted LED ones once they
    became available.)

    When one of the IKEA globes failed - after a several years- I bought a
    dimmable globe of Amazon ( in fact a pack of 3). They were hopeless.
    Erratic dimming and like a cigarette end. I returned them.
    I ordered some non- globe dimmables, which are fine.

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  • From Harry Bloomfield Esq@21:1/5 to Theo on Wed Dec 25 11:12:12 2024
    On 24/12/2024 13:24, Theo wrote:
    Another option is to fit one halogen bulb in the fitting which gives a more continuous current waveform through the whole cycle. I have a V-Pro dimmer with some dimmable GU10s and without that they flicker at low dim settings.

    I bought a pair of dimmer switches, which claim to be able to self
    adjust, to suit either leading, or trailing edge dimmable LED lamps. I'm
    not clear how that works?

    These were to replace a pair of ancient dimmers, which had continued to
    work fine, after I had swapped the lamps from halogen, to dimmable LED,
    but the LED lamps were just too low wattage. I replaced them with higher wattages, but then they no longer dimmed, so time for new dimmers to suit.

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  • From Max Demian@21:1/5 to All on Wed Dec 25 11:47:44 2024
    On 24/12/2024 12:16, alan_m wrote:

    I've just installed a new light fitting with dimmable LED bulbs and it's connected to an existing light dimming switch.

    The bulbs don't dim at all, just stay at full brightness.

    This is a good argument for a 12V DC supply for lighting. Then PWM
    dimmers can be employed.

    --
    Max Demian

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  • From alan_m@21:1/5 to All on Thu Dec 26 10:21:07 2024
    On 24/12/2024 12:16, alan_m wrote:

    I've just installed a new light fitting with dimmable LED bulbs and it's connected to an existing light dimming switch.

    The bulbs don't dim at all, just stay at full brightness.

    Update:

    Fitted a V-pro dimming switch as suggested in this thread. The lights
    now dim as expected on the default trailing edge mode. I haven't had to programme any of the other functions.



    --
    mailto : news {at} admac {dot} myzen {dot} co {dot} uk

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  • From charles@21:1/5 to max_demian@bigfoot.com on Fri Dec 27 18:30:04 2024
    In article <vkgrd0$2cilq$1@dont-email.me>, Max Demian
    <max_demian@bigfoot.com> wrote:
    On 24/12/2024 12:16, alan_m wrote:

    I've just installed a new light fitting with dimmable LED bulbs and
    it's connected to an existing light dimming switch.

    The bulbs don't dim at all, just stay at full brightness.

    This is a good argument for a 12V DC supply for lighting. Then PWM
    dimmers can be employed.

    The current needed is 20x that at 240v!

    --
    from KT24 in Surrey, England - sent from my RISC OS 4té˛
    "I'd rather die of exhaustion than die of boredom" Thomas Carlyle

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  • From Max Demian@21:1/5 to charles on Sat Dec 28 12:32:57 2024
    On 27/12/2024 18:30, charles wrote:
    In article <vkgrd0$2cilq$1@dont-email.me>, Max Demian <max_demian@bigfoot.com> wrote:
    On 24/12/2024 12:16, alan_m wrote:

    I've just installed a new light fitting with dimmable LED bulbs and
    it's connected to an existing light dimming switch.

    The bulbs don't dim at all, just stay at full brightness.

    This is a good argument for a 12V DC supply for lighting. Then PWM
    dimmers can be employed.

    The current needed is 20x that at 240v!

    LEDs use hardly any power.

    --
    Max Demian

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