Halogen lights flickering on dimmer

[Daskew78]

Hello,
First time poster and I have no electrical experience what-so-ever.

I have recently converted an attached garage into a room. We built a false ceiling and put in 8 halogen spotlights with a transformer on each, connected to a dual dimmer switch (each switch controls 4 lights).

When the lights are not turned up full, some of the flights flicker slightly which is pretty annoying. I called the electrician back who installed them but he's as puzzeled as me.

We tried changing the bulbs and it's not that.
We tried changing the transformer, it's not that.
We tried changing the dimmer switch and it seems to swap which lights are affected. So we think it's this, but unsure why or how to fix it.

He's gone away to check with his supplier and the manufacturer of the dimmer to see if they have had any issues like this but I thought I'd have a look online.

Anyone experienced anything like this before?

Cheers in advance.

 

[pjcomp]

PResumably the dimmer was chosen to work with halogens and transformers? Some are a bit fussy about what they attach to ...

PJ

 

[Daskew78]

errm no? Didn't realise it needed to be. It just said minimum 60watts and maximum 800watts.

 

[ban-all-sheds]

There is a compatibility issue with dimming ELV lighting "transformers" (in quotes because they aren't actually transformers, which is why the problem arises)

Dimmers do not work by lowering the peak voltage, they reduce the RMS voltage by simply chopping out part of the waveform - they either turn on part way through each cycle (leading edge, or phase-delay) or turn off part way through (trailing edge, or phase cut), and what the dimmer does must match what the transformer needs.

So you might have a "transformer" that is labelled as suitable for dimming and you might have a dimmer switch that is suitable for use on ELV power supplies but you still need to match the leading/trailing edge characteristics of each.


But in any event, 8 lights?

Unless your garage was large enough to be used by the Sultan of Brunei did the fact that you needed so many not make you realise that you were trying to light a room with lights not designed to light rooms, in fact with lights specifically designed to not light them?