admins: Sorry if this is not appropriate, or in the wrong place...
Good morning!
I am, well, puzzled by this situation: Being an old-school-type of guy, I still use halogen-lights wherever it seems not too unreasonable. Now, there's this little reading-lamp I use next to my bed and in the home-office, italian 80ies style. It's one of these late 80ies design-things, has "gliding contacts" to the bulb, runs on 12V AC, 35W, and has an on-off switch at the head (just before the lightbulb) and not much more.
Now, they seem to go down: The lamp seems fine (xformer stays cool) but when it's on the xformer suddenly turns very hot and stops working, until it is back to normal levels when unplugged and here it is again...
I wanted to check so got the other lamp: The transformer in the homeoffice is hot although the lamp was off for at least the night. I thought a lamp would not draw current when off???
here's the link to the lamp if anyone is interested: https://www.luceplan.com/products/berenice-table
Good morning!
I am, well, puzzled by this situation: Being an old-school-type of guy, I still use halogen-lights wherever it seems not too unreasonable. Now, there's this little reading-lamp I use next to my bed and in the home-office, italian 80ies style. It's one of these late 80ies design-things, has "gliding contacts" to the bulb, runs on 12V AC, 35W, and has an on-off switch at the head (just before the lightbulb) and not much more.
Now, they seem to go down: The lamp seems fine (xformer stays cool) but when it's on the xformer suddenly turns very hot and stops working, until it is back to normal levels when unplugged and here it is again...
I wanted to check so got the other lamp: The transformer in the homeoffice is hot although the lamp was off for at least the night. I thought a lamp would not draw current when off???
here's the link to the lamp if anyone is interested: https://www.luceplan.com/products/berenice-table
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The obvious thing to do is to swap the lamp and see if the problem goes with it.
If so, replace the lamp. If not, replace the xformer.
The switch appears to be in the lamp circuit, so the transformer primary is on the mains all the time and will get warm, hopefully not hot.
Nice lamp btw.
Jan
If so, replace the lamp. If not, replace the xformer.
The switch appears to be in the lamp circuit, so the transformer primary is on the mains all the time and will get warm, hopefully not hot.
Nice lamp btw.
Jan
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.
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.
PS the transformer is on all the time, burning through a few Watt of energy. On the lamp you switch only the less dangerous 12V.
If you go for a LED and SMPS you should get one that plugs directly into the mains (wall wart). These are usually "green" and use only a fraction of a Watt while at idle. Your electricity bill will drop significantly, be prepared to save about a Franken per year...
If you go for a LED and SMPS you should get one that plugs directly into the mains (wall wart). These are usually "green" and use only a fraction of a Watt while at idle. Your electricity bill will drop significantly, be prepared to save about a Franken per year...
Thanks to both, @jan.didden and @Turbowatch2 …
I have to admit I thought the tranny wouldn’t draw anything if no load on its secondary…
A few years ago, we had a serious installations-issue (where a nice radio went up in smoke while in standby), so this could have damaged the trannies as they seem to be „online“ all the time? (Amazing as there are others in the house, troublefree)
Those lamps btw. had a glorious appearance in a (glorious) cronenberg spooky movie, dead ringers…
I have to admit I thought the tranny wouldn’t draw anything if no load on its secondary…
A few years ago, we had a serious installations-issue (where a nice radio went up in smoke while in standby), so this could have damaged the trannies as they seem to be „online“ all the time? (Amazing as there are others in the house, troublefree)
Those lamps btw. had a glorious appearance in a (glorious) cronenberg spooky movie, dead ringers…
This sounds like a shorted turn, possibly more, in the primary - so the transformer is junk (and a hazard, as noted above)
It could be taken apart and the bobbin rewound, but perhaps easier to find a new transformer or LED transformer (SMPS) that can supply 3A at 12V.
Don't forget that only one of the xformers may be broken; the other seems OK.
And we still don't know if it is the xformer or the lamp.
It's a simple, logical and smart test: swap the lamp bulb to the other lamp and see if the xformer of that lamp then gets too hot.
If so, its the bulb, and both xformers probably are fine. If not, you have identified the broken xformer and are sure that the other is OK.
I am always amazed at the speculation these kind of posts generate with nobody aparently interested in the real cause.
Jan
And we still don't know if it is the xformer or the lamp.
It's a simple, logical and smart test: swap the lamp bulb to the other lamp and see if the xformer of that lamp then gets too hot.
If so, its the bulb, and both xformers probably are fine. If not, you have identified the broken xformer and are sure that the other is OK.
I am always amazed at the speculation these kind of posts generate with nobody aparently interested in the real cause.
Jan
But over half of the first post is stuff that has nothing to do with the issue so it's easy to get confused with all the ramblings
.Jan
Agreed, as a source of evidence to pinpoint a fault, it's somewhat ambigious!
More testing required I think!
The description of when the transformer is heated is a bit unclear. If that transformer does not heat up by itself when it is connected to the mains and switched ON, when the lamp is not connected, and there is 12-13VAC on the secondary, then everything is fine with the transformer and the problems should be looked for in the lamp. It is old, maybe the insulation of the wires has loosened somewhere, so they need to be replaced. If the switched ON transformer heats up without a connected lamp, then the problem is in the bridged windings in the primary or secondary, and that is thrown away and a new one is bought. Transformer 12VAC or DC power supply of appropriate power according to the power of the lamp, and it is better to be twice as strong.
It's a simple, logical and smart test: swap the lamp bulb to the other lamp and see if the xformer of that lamp then gets too hot.
If so, its the bulb, and both xformers probably are fine. If not, you have identified the broken xformer and are sure that the other is OK.
But yes, it's quite a job, will take you at least 10 minutes.
Needs careful scheduling and thinking ahead but you can do it if you really want to!
Jan
If so, its the bulb, and both xformers probably are fine. If not, you have identified the broken xformer and are sure that the other is OK.
But yes, it's quite a job, will take you at least 10 minutes.
Needs careful scheduling and thinking ahead but you can do it if you really want to!
Jan
@myleftear If the problem is in the transformer, and you want to keep the original look of that combination (usually that's what you want in vintage devices - originality), then you should consider rewinding that transformer or getting a new one that fits in that original case. If I own it, I would definitely replace the wiring regardless of the condition of the transformer.
These are 12V 35W and 25W … don’t know but I wouldn’t bet on them being geeignet…I still think that somehow these lamps could (and should!) be converted into audio devices, surely the best lamps would be directly heated triodes, or some giant tubes that light up like incandescent lamps
Then they could be both lamp and amplifier!
And, BTW, @jan.didden , apologies for again switching into chat-mode, and blurrig the topic.
Will do those tranny-swaps in the afternoon just to see what happens…
Your Luceplan Berenice lamp is still in production and sought after, like several other iconic Italian design lamps from that era. Street prices for old lamps in like-new condition are often higher than the list price of current production ones. Berenice is a comparatively inexpensive lamp, I believe that it is about 500 euro; many vintage designer lamps are sold at 1000 euro or more.
Italian desiger lamps are comparatively common were I live and well worth the expense of a repair when they broke, so I've repaired or restored several of them over time. They are beautiful objects built to last and have have a collector value that may increase over time (depending on future popularity of the design), so it is imperative to change the apparence as little as possible. You also need to check the official manufacturer literature and see what parts are depicted because the lamp will lose value if they are modified, even a different screw matters if there is a picture of it. You are lucky because the power supply is not depicted so you can replace it with a modern, more efficient one, although it would be best to find a SMPS naked module that can fit inside the original enclosoure. It is very likely that someone else will replace the power supply again 20 or 30 years from now, so every repair should be reversible.
The original transformer, with double insulation, becomes warm because it draws about 3W when the lamp is off due to inefficient magnetic design, and it is normal. This may lead to shorted turns over time. It you need to replace it, you must use a medical grade, double insulated (no ground connection) SMPS from a reputable manufacturer because the output wires are exposed to the touch. For the same reason, it must have a good short circuit protection and current limitation calibrated to the need of the 35W alogen lamp because the wires may be accidentally shorted out and this may pose a hazard. On my experience, faulty/damaged wires are also a common issue.
Italian desiger lamps are comparatively common were I live and well worth the expense of a repair when they broke, so I've repaired or restored several of them over time. They are beautiful objects built to last and have have a collector value that may increase over time (depending on future popularity of the design), so it is imperative to change the apparence as little as possible. You also need to check the official manufacturer literature and see what parts are depicted because the lamp will lose value if they are modified, even a different screw matters if there is a picture of it. You are lucky because the power supply is not depicted so you can replace it with a modern, more efficient one, although it would be best to find a SMPS naked module that can fit inside the original enclosoure. It is very likely that someone else will replace the power supply again 20 or 30 years from now, so every repair should be reversible.
The original transformer, with double insulation, becomes warm because it draws about 3W when the lamp is off due to inefficient magnetic design, and it is normal. This may lead to shorted turns over time. It you need to replace it, you must use a medical grade, double insulated (no ground connection) SMPS from a reputable manufacturer because the output wires are exposed to the touch. For the same reason, it must have a good short circuit protection and current limitation calibrated to the need of the 35W alogen lamp because the wires may be accidentally shorted out and this may pose a hazard. On my experience, faulty/damaged wires are also a common issue.