Eliminating LED flicker with FGD211

[Ben 0]

Hi,

I've got a number of dimmable GU10 LED lights connected to the FGD211 Universal Dimmer. I've got two models of lamp in the circuit - both on this page (Link:

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); 9 of one and 2 of the other (2-wire configuration). I've got two weird observations - one that I cannot dial out flicker by adjusting parameter 20 (ms pulse duration). The second odd thing is that even when the switch is 'off' the lights remained dimly lit. I don't know if those issues are related. Fingers crossed... hopefully resolution of one will help solving the other, easier.

My total load is 44W (11 x 4W) so I'm assuming that the behaviour I've observed is not related to a 'minimal load' on the Fibaro unit - because the load is in excess of the stated 25W threshold.

I've asked the retailer to provide the ideal pulse duration value - and they're going to check that with their manufacturer. But it's occurred to me, could this flickering be due to, or at least made worse by, the fact that I've got two models of lamp on the same circuit?

thanks,

Ben

[deanrparry 19]

Never had an led gu10 work yet with or without bypass over 25w with cree and smd5059 bulbs so I know your pain..

[Ben 0]

Quick update - the flickering was mostly resolved after removal of one type of lamp from the circuit. I had 9 of one type (50W equivalent) and 2 of the other type (60W equivalent). After removing the two 60W equivalents the lights are far more stable. I tried briefly re-adding the 60W equivalent, and the flickering returned. So having two types of lamp definitely made things worse. I'm now back to one type only (and will need to buy another two of the 50W equivalents).

The lamps are still dimly illuminated when they're supposed to be 'off'. I've got a spare dimmer bypass so I may try putting that in circuit to see if it helps. I don't want to - because I don't really want to add 25W of load!

[ Added: 2013-08-03, 17:08 ]

...and addition of a Fibaro Dimmer Bypass does allow the LEDs to turn fully off. So I'm pretty much sorted now :-> Just a matter of fine tuning parameter 20. I'm using value 133 right now - and that's an acceptably low level of flicker for now.

[Lockzi 1]

My experience is that it is highly related to load on the circuit.

I have same dimmers and same LED spotlights running on different circuits, depending on the amount of LED Spotlights the value changes. You just have to try it out, I don't think that the manufacturer could give you the right values. What normally happens for me is that I have a specific dim level set, let's say 70% and I get it to be fairly stable. When I change the dim level, it starts to flicker again. It's hard to get it to be solid throughout the whole dim range, but it is possible.

Don't forget to adjust min-/max dim. On some LED lights the brightness does not increase to the same amount of current being raised. It could hit it's max at as low as 55%, set that to your max dim level if so.

[Ben 0]

I think you're right - there may well be a relationship to load. I noticed more flickering at low brightness levels than at higher brightness levels. That could be a subjective 'eye thing', but I suspect it's true.

I'm dimming between 20% to 99% of 'real' values. That 20% figure was from the manufacturer. However I may raise that floor to help dial out the worst of the flickering.