Dimmer 2 with LED's experiences

[Guest azevenhuizen]

Anybody has some experience to share about dimmer 2 in combination with LED's?

 

I am about to replace all my dimmer 1's for dimmer 2's as we keep having issue's with the led's here.

Like humming lamps, flickering, failing bulbs, etc.

 

 

[tvs 1]

Hey, I've just installed 4 of them, with mixed success. In my kitchen (12 Philips master 6w led) and 3m of led strip powered by a dim marble driver it works very well, no humming at all (used to be very loud hum with a dimmer 1. In the other rooms I get a slight flicker, although I think that's to do with the minimum load. Also I don't have the bypass installed, which should sort out any problems.

The main issues are to do with associations, basically they don't work. I can get it working with other fibaro units but it's useless with anything else. They've also disabled the triple click scene activation on s1 which seems stupid to me.

[Guest azevenhuizen]

Thanks for sharing.

Do you know if, by any chance, we can use the bypass-1 on dimmer-2? I have a couple of these which I don't use.

[petergebruers 1,268]

No, new dimmer has a different design and has its own bypass. From the manual: "FIBARO Bypass 2 (FGB-002) is a device designed to work with FIBARO Dimmer 2 (FGD-212). It should be used in case of connecting lED bulbs or energy saving compact fluorescent lamps. FIBARO Bypass 2 prevents flickering of the lED lights and glowing of the turned off compact fluorescent lamps."

[Guest azevenhuizen]

Makes me wonder what the bypass 2 actually does, as in my humbel opinion it is just a simple resistor.

[petergebruers 1,268]

Makes me wonder what the bypass 2 actually does, as in my humbel opinion it is just a simple resistor.

I like the fact that you try to reverse engineer this thing! You're my guy!

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No, neither bypass 1 nor bypass 2 are simple devices. A resistor would work... Like adding an incandescent light bulb might help. But it would consume more energy, and the limiting of the voltage across the lamp wouldn't be as precise.

The bypass acts more or less like a switch. When the dimmer is off, the bypass closes. The small current that is needed to "feed" the dimmer (especially with 2-wire setup but also 3-wire), goes through the switch. This keeps the voltage across the terminals of the light bulb so low, that it can't start or glow. Hence the name "bypass". When you set the dimmer to anything > 0% the bypass detects this (and there's the magic... I don't know what the circuit looks like) and switches itself off. I checked it with a random LED bulb. Without the bypass, the voltage rises to roughly 180 Volt peak in a few seconds. Then it flashes and discharges and the cycle starts again. Different lamps, different cycles. I have an Osram that "pumps" but doesn't switch on the light. Clever engineering. So not all types have this annoying stroboscopic effect. This is a 3-wire setup. When you add the correct bypass, the voltage can only rise up to about 10 Volt. That's way below the threshold...

[Guest azevenhuizen]

I like the fact that you try to reverse engineer this thing! You're my guy!

Please login or register to see this image.

/emoticons/default_icon_smile.gif" alt=":-)" />

No, neither bypass 1 nor bypass 2 are simple devices. A resistor would work... Like adding an incandescent light bulb might help. But it would consume more energy, and the limiting of the voltage across the lamp wouldn't be as precise.

The bypass acts more or less like a switch. When the dimmer is off, the bypass closes. The small current that is needed to "feed" the dimmer (especially with 2-wire setup but also 3-wire), goes through the switch. This keeps the voltage across the terminals of the light bulb so low, that it can't start or glow. Hence the name "bypass". When you set the dimmer to anything > 0% the bypass detects this (and there's the magic... I don't know what the circuit looks like) and switches itself off. I checked it with a random LED bulb. Without the bypass, the voltage rises to roughly 180 Volt peak in a few seconds. Then it flashes and discharges and the cycle starts again. Different lamps, different cycles. I have an Osram that "pumps" but doesn't switch on the light. Clever engineering. So not all types have this annoying stroboscopic effect. This is a 3-wire setup. When you add the correct bypass, the voltage can only rise up to about 10 Volt. That's way below the threshold...

 

Interesting. Thanks for the insight.

It sure makes a lot more sense as this approach will not consume aditional power.

 

I actually thought it was just a sort of pull-down resistor, creating some fake load on the output of the dimmer, which causes it (probably a triac) to close properly.