Got a not audio transformer problem

[myleftear]

Buona sera pcan
thank you for these heads-ups!
I've just been running both transformers on the one lamp—both get very warm while the lamp is on. I'll have to check the bulb, as this is a replacement I found on a auction-site, maybe it is not what it should.

Letting the transformer cool down (unplugged), and will then run the other lamp to see how this behaves.

The transformer that gets hot with the lamp being off will be replaced. I don't mind cannibalizing a sought-after designer-icon, as this appears to be a, sorry to say so, average industrial mass-production stuff. (The berenice itself is still one of the great designs full of great engineering ideas!)

 

[tiefbassuebertr]

Please don't use it any more, there seems to be a serious problem with the transformer, which may burn up your house in the worst case.
The simple solution is to puy a 12V-5A SMPS and use it. If you find one of the right size, it may even fit inside the transformer box.
If you use an LED bulb instead of the halogen type, you should only need a very small SMPS, something like 5 Watt instead of 45.

I know the transformer showed in post #1. It is an inferior version (as is often the case with Italian design lamps for 12V). This transformer definitely needs to be replaced by a high quality version.

Another disadvantage is the fact that the lamp switch is not a main switch, which interrupts the 230VAC.
Due to the high contact stress (only 12V but 20 times higher current flow), the switch fails much earlier than if it were in the 230V primary circuit, which often leads to the entire halogen set-up ending up as electronic scrap and being replaced as a whole by buying a new one.

SMPS-versions often also suffer from this disadvantage - this further reduces the already short additional the lifetime of the SMPS.
In general - I don't like SMPS which are not make for repair service and thus no service manual therefore available.
Any guys do this without such a manual despite the complexity - go to
https://www.giangrandi.ch/electronics/smpsfix/smpsfix.shtml
because in any cases the elcaps failure due bad quality and short life time (check out attached image for an example).

Thus I prefer old school transformers instead SMPS versions like this one:
https://www.reichelt.de/de/de/halogen-trafo-300-w-hal-trafo-300va-p24818.html?r=1
very expensive in new condition unfortunately (compared to a SMPS).
But age doesn't matter with high quality designs - therefore versions in used condition is a good choice and not too expensive:
https://www.ebay.de/itm/186349308729
https://www.ebay.de/itm/145628545227
Don't use a switch between transformer and lamp in the 12V leads and use a usual switched extension lead like this one under
https://www.kaufland.de/product/396093501/
or Brennenstuhl eco-line - search under
www.brennenstuhl.com.

 

[tiefbassuebertr]

If you find 30-40 years old white halogen transformers from the probably defunct German brand "ABN", you will get very high quality/reliability.
Obviously this brand currently don't longer manufacturing this transformers:
https://www.abn-electro.com
The German supplier "DEKO_LIGHT" sold a lot of these transformers at a time when SMPS were still rarely offered.

Sometimes one can even find these in the electronic scrap at the recycling center because young people simply throw them away (usually out of ignorance or because of a defective fuse) despite them working perfectly.
Like many amplifiers, these transformers have built-in fuse holders.

 

[myleftear]

Thanks, tbü, for the hint! I'll look around...
(Had a quick look for trannies at our bay, 99% SMPS) so I'll have to dig a little deeper.