Halogen spotlights - now not working!!!

[Dave Jennings]

Hi everyone,

Hope someone here can help.

We have 4 12v/50w halogen spotlights through a transformer, set in a false ceiling, and over the last few weeks three of them have stopped working.

I switched the bulbs but this made no difference at all.

I checked the one that worked with the bulbs I'd bought, just to make sure I hadn't gotten a bad batch of bulbs. All bulbs work but only when in the single spot that works.

Now, I'm a total numptie when it comes to anything like this. Has anyone any ideas / clues that I can try to see if I can fix these? As I say, the wiring etc for these is in a "shielded" area, ie there's the ceiling that the spots come out of, then there's a small gap, then above that is the floor of an overhead built in cupboard.

Many thanks in advance - I'd hate to go to the expense and hassle of getting a sparky in, in case it is something I can look at myself.

[Mike Hibbert]

Hi Dave,

How much space is there between the floors? I.e. from the ceiling with the lights and the cupboard? It may be that they are overheating. It sounds to me like the transformers have all gone, so it should only be a case of replacing them.

Mike

[Dave Jennings]

Mike Hibbert yik-yakked:

Hi Mike,

if memory serves, they left something like 10 - 12" gap. Is that enough, or, if you think, the transformers are gone, then:

does each unit has its own transformer? I assumed there would be 1 central transformer that the 4 lights ran off, so is this incorrect?

If each unit does have its own transformer, are they attached to the top end of the spot? I'm just owndering if the floor/celing area would have to be opened up.

Many thanks - sorry more questions than my OP!!

Dave.

[Mike Hibbert]

Dave,

Mine have got a transformer for each bulb (well, thats what it looks like to me!). 10" - 12" is maybe on the short side for 50w bulbs, the wiring should say the minimum gaps on it. I think mine is something ridiculous like 50cm for a 50w bulb.

The transformer would be close to the bulb, so yes, the floor may have to come up upstairs.

Cheers Mike

[Dave Jennings]

Mike Hibbert yik-yakked:

Hi Mike,

Thanks a lot for your replies, I appreciate them.

One final question - hopefully!

What should the transformer look like? For some reason, I'm imagining a largish black box, but then maybe that's my old Scalextric kit I'm thinking about!

I might have a look and see what's near to hand before calling in the pros and having the flooring lifted!

[stuart noble]

These transformers don't seem to last long. I have replaced a couple where they were built into the fitting but it's hit and miss whether you can get one to fit and, at £12, hardly worth the aggro.

[Mike Hibbert]

Well, mines about 5 inches long and about an inch wide (and the transformer........ ho ho). It is screwed to the beam next to each light.

good luck!

Mike

[ARWadsworth]

If one transformer supplied all the lights then the fact one light is working would suggest the transformer is working.

If they are individual transformers then you can usually pull them through the hole after removing the downlighter to replace them.

The question I have to ask is did all 3 lights stop working at the same time? Your OP suggests not, but it is worth asking.

Adam

[David M]

These are typical dimensions for a switched mode transformer. These can have advantages over a toriod in that they are small and can be very efficient, BUT they do require careful design AND high quality components to work reliably. In particular the capacitors can be pushed close to there absolute maximum ratings.

I've got a couple of cheap units from B&Q in the bathroom, and while I first had trouble with a bad batch of bulbs which B&Q eventually replaced, I've now got one unit where one bulb has gone and another flashes late at night. Every cost saving possible is required in these low end units and I suppose that I shouldn;t really be surprised that the they have thrown up a few problems.

they were a bit of a spur of the moment purchase and I would now certainly avoid the cheap units that are available and pay an extra couple of quid for some decent transformers.

cheers

David

[Dave Jennings]

Mike Hibbert yik-yakked:

Brrum-ching! It's like having Jimmy Tarbuck give you advice.

Thanks - awkward space but I'll try to ahve a look here first!

[Dave Jennings]

ARWadsworth yik-yakked:

Thanks - that goes back to my thought that there was one transformer that all the lights "fed" off.

I'll try to see, although the spacing's a bit tight.

Nope, all at separate times.