Dimmer Switch Problem?

Joined
5 Jun 2006
Messages
24
Reaction score
0
Country
United Kingdom
Hi All,

I have recently fitted a ceiling light with x10 12v 10watt G4 halogen light bulbs - the light itself has a built-in transformer.

The light also has 2 switches operating it. One is a standard 2-way light switch and the other is a dimmer switch (a special dimmer switch that can deal with transformers). Both switches are 200w.

The problem is that when I switch the light on there is a faint buzzing noise coming from the dimmer and a faint buzzing noise coming from the transformer in the light itself. Then, when I turn the light off at the dimmer switch and turn it back on using the standard switch, the same faint buzzing noise can be heard from the light and and can also be heard from the standard light switch.

Is there a problem?


Many thanks - this is a great forum!
 
Sponsored Links
Thanks for the above hyperlinks, but the above problem I have posted is of a different nature to the information provided.
 
your light - does it have a round cylinder-shaped base with a similarly shaped transformer in it that fill sthe base? if so, its a wire-wound transformer, most dimmer switches will have trouble with these.

If you can, bypass this transformer and fit your own electronic dimmable transformer in the ceiling space.
 
Sponsored Links
crafty1289 said:
your light - does it have a round cylinder-shaped base with a similarly shaped transformer in it that fill sthe base? if so, its a wire-wound transformer, most dimmer switches will have trouble with these.

If you can, bypass this transformer and fit your own electronic dimmable transformer in the ceiling space.

Or he could use the MK dimmer I provided a link to in his other post on the exact same subject.

//www.diynot.com/forums/viewtopic.php?p=406291&highlight=transformers#406291
 
RF Lighting said:
crafty1289 said:
your light - does it have a round cylinder-shaped base with a similarly shaped transformer in it that fill sthe base? if so, its a wire-wound transformer, most dimmer switches will have trouble with these.

If you can, bypass this transformer and fit your own electronic dimmable transformer in the ceiling space.

Or he could use the MK dimmer I provided a link to in his other post on the exact same subject.

//www.diynot.com/forums/viewtopic.php?p=406291&highlight=transformers#406291
yeah, you could do that. in fact, i was patiently waiting for RF to come along with that link.

but isn't it a bit cheaper to buy a new transformer? :LOL:
 
Thanks guys.

I already thought I had bought a dimmer switch that could handle the light, obviously it can't. (And yes the light has a cylindrical base which contains a transformer of the same shape).

I think I might just give-up, as since making this post, the transformer in the light started crackling very violently, so I had to turn it off immediately. I just wanted to be sure what the problem was, yet I still can't diagnose it, as the same light started crackling with 2 standard switches before I tried the dimmer switch, which leads me to think it could be my electrics. I actually took the first light back to the shop as the transformer had totally burnt out and had made the light's metal casing live!! This is the 2nd light of the same model and this also seems to be going the same way.
 
does your lighting circuit have an earth?

was the crackling definitely coming from the transformer? :eek:

the problem with that transformer is that it draws high current on startup (particularly as it is connected to a halogen load which also draw high current), thus will wear out the electronics in a dimmer. Dimming may make it vibrate and hum loudly, because a dimmer actually slices up the phase to the light - so it switches on and off 50 times a second. wirewound transformers dont like this, and may overheat or simply stop working.

Electronic transformers are more tolerant of it, and most are made to be compatible with dimmers nowadays. Why they still make lights with WW tx's, i dont know. Must be cheaper? (though i cant think how several hundred metres of copper wire and a bit of iron is cheaper than a few resistors and capacitors and a PCB)
 
i think there is more chance of a wirewound transformer frying a dimmer (the current in a big coil doesn't change quickly without a LOT of voltage applied) than a dimmer frying a wirewound transfomer.
 
Indeed, the lighting circuit is earthed.

The loud crackling definately came from the light itself - this was also true before I tried a dimmer - I had 2 standard 2 way light switches before I tried the circuit with a dimmer and I still had the same problem with the light starting to crackle and in effect, burn itself out. I thought the light was faulty so took it back and got a replacement, I now have the same problem, but cannot think how the lighting circuit could be doing this - could both lights be part of a faulty batch?
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top