Led lights flicker

Discussion in 'Electricians' Talk' started by spen123, Oct 24, 2021.

  1. spen123

    spen123 Active Member

    Morning all
    I've got some led lights in my kitchen that are on a dimmer switch.
    They flicker when down low but only start to do this after being in for 5 minutes.
    They did work fine.
    Can intest for anything or am I looking at replacing the fittings?
    8 in total on a dedicated circuit due to being in an extention.
     
  2. Hell68

    Hell68 Active Member

    Im no expert but sounds like it could be either the dimmer isn't compatible with the leds. Solution... change the bulbs to halogen or change the dimmer switch to trailing edge (if its a leading edge dimmer).

    Or if it is in fact a trailing edge dimmer you might have exceeded the maximum load for the switch.
     
    spen123 likes this.
  3. Bazza

    Bazza Screwfix Select

    More likely not achieved the minimum load for the dimmer!
     
    Hell68 and seneca like this.
  4. MGW

    MGW Screwfix Select

    I had the same, not a dimmer switch, it was an electronic on/off switch that could be worked with a remote control or phone. We had G9 bulbs and I found there is a whole range of G9 LED bulbs. This is a picture of two G9-comp.jpg about to scale, and the large one has a smoothing capacitor inside nearly as big as the small bulb. The small bulb is designed to fit inside the glass cover required for the quartz bulb which would have retained the white hot parts of the quartz bulb if it exploded which can happen, also it stopped the harmful rays from the quartz bulb damaging our skin, unless high up so quartz cool when it reaches the ground and the rays dissipated, all quartz bulbs were used behind glass.

    So when replaced with LED there is not need for the glass, so you can use the larger bulb, but they look very different and we tend to buy a chandelier or any other light fitting as much for what they look like as to light the room.

    The large bulb does not have lumen or watts marked on bulb, so illegal to sell in the UK. So you can't buy in UK shop, internet only.

    There are Compatibility Charts one linked to is for Energenie light switches, for G9 it lists Philips Master 2.3 watt and says "No flicker apparent on any tested bulb" but in my house they did flicker. What we have is an interaction between the components used in the switch and those used in the bulb.

    Many bulbs use a capacitor to limit current used, capacitors and coils can form a tuned circuit this is how old radios worked, and we are using AC current, the switch also has coils in it, and some times we have an interaction between the two.

    If the bulbs had on the package smoothing capacitor fitted we could select a bulb unlikely to flicker, but it is a case of suck it and see.

    So in general if you want to use a dimmer switch use a large (physical size) bulb, as more likely to have a smoothing capacitor fitted. But best idea is use a smart bulb, so all built into one device so will work with each other. If the bulb type does not allow use of a large bulb, use an electronic control which requires a neutral.

    I used this relay DSC_6061.jpg inside the light fitting DSC_6057.jpg details here DSC_6060.jpg this allows me to select centre or outer bulbs giving three levels of lighting, and can be controlled from light switch or phone in same way as two way switches. The centre bulb is actually a smart colour changing bulb so it can change the colours of dangling bits once fitted over the stairs.

    With the two bulbs shown, until I found a bulb that did not flicker, I used 4 LED and one quartz, which stopped the flicker.
     

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