Dimmer Performance (LED Lights) at Max %- Universal Dimmer

Discussion in 'General Discussion' started by glen_m, May 14, 2022.

  1. glen_m


    Jun 26, 2016
    Likes Received:
    I recently brought a sample of LED downlights to test compatibility with C-BUS dimmers (L5504D2U), from a local NZ supplier, before I rushed in and bought a load of 50 or so, to replace all the remaining Halogen IRC downlights in my house.

    Initially my testing was focused on reasonable linearity across the dimming range, and to determine an acceptable minimum dimming %age for differing combinations. The results I found were that these units seemed to be completely flicker-free in the following ranges/combinations:
    • 1 fitting - 1% - 95% (I don't have any 1 fitting circuits but tried this just for the sake of it)
    • 2 fittings - 1%-99%
    • 3 fittings - 1%-100%
    • 4 fittings - 1%-100%
    (A little disclaimer here - This is visual observation, not scientific measurement.....)

    So what surprised me a bit, was that the only flicker I observed was at the top end of the dimming range, none at the bottom end, where I had initially expected (and have also seen in other fittings, where I have just thrown a minimum %age setting on the dimmer range, to resolve this). As an aside, the dimmer detects/sets the channel to "Normal - Trailing Edge".

    Now that I am aware of this characteristic, I believe it may also be a similar thing for some LED bulbs I brought from Europe, but will need to play around some more to fully test this.

    Given my testing, I am going ahead with the purchase of the remaining fittings, which do look well made, and with the exception of one circuit, all mine are >3 fittings. which performed well. For the one 2 way circuit I have in the house, whilst I think the 'Load Corrective Device' from clipsal might sort it, there is no discernible difference between 99% & 100%, so I will just set a maximum limit of 99% on the dimmer).

    Has anyone else experienced a similar thing with LED fittings, with flicker right at the top-end of the dimming range, rather than at the bottom? Did the load corrective device resolve it, or did you take a similar approach to that which I plan to do (setting a max %)?

    glen_m, May 14, 2022
    Conformist likes this.
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