Identify transformer

Hi

Please see attached photos. This is 12v battery charger, 230v to 14v Leisure Battery Charger.

The charger has failed, and I'm trying to help my customer by repairing it rather than replacing the whole unit.

After testing I think this transformer is the cause. As you can see the sooting of the pcb, and the damage on the underside of the block.

I can't find any information about this component. There is no writing on it other than the label you can see. Nordelectronica don't respond even to engineers like myself, they told me that themselves!!

Help would be appreciated.

Custom made switch-mode transformer, almost certainly impossible to source - the only place would be the actual manufacturer of the board, assuming they even keep spares.

Thank you, like I said they don't talk to engineers!

I just thought there might be a chance.

Cheers

I'm not sure that the transformer is a high frequency transformer. I think the open construction transformer between the pictured transformer and the toroidal inductor is the high frequency one. The marking on the transformer that has been removed from the board is marked 230/19.9Vo which MAY indicate the primary and secondary voltages. NOTE the transformer on the board has a different part number. I suggest tracing enough of the schematic to see if the primary is connected directly to mains voltage. This maybe just supplying control voltages.

Les.

Hi Les
Sadly no schematics. I did think about getting hold of a similar value transformer and just try it, if it doesn't work that's OK, at least I did my best. I'll just rewire a new charger unit.

Thank you for your reply.

Cheers

It should not be difficult to trace enough of the schematic to see if the transformer is supplied at mains frequency or if it is supplied from some sort of high frequency oscillator. (This could be from a switch mode regulator IC or a high voltage transistor or mosfet.)

EDIT. I have just noticed the place on the board where the transformer was removed from. (I thought it was the same transformer removed from another board.) I notice that there a four diodes just above the place where the transformer was located. I think these probably form a bridge rectifier. The part number of these diodes may give us an idea if the transformer is working at mains frequency or some higher frequency.

Les.

It's a MOFSET, so yes, I'll sit and trace the circuit.

Cheers

Yes Les!! I'll check them

That looks to me like a low power 50 / 60 Hz transformer. If so, the input resistance will be 1 kOhm or so, and the input will be connected to the mains.

It looks something like one of these:- https://uk.farnell.com/myrra/44268/transformer-10va-15v/dp/1689089

If the original is a main frequency transformer, there may be standard transformers that will work, of you could have an off-board transformer with leads to the circuit board.

Diver300 said:

That looks to me like a low power 50 / 60 Hz transformer. If so, the input resistance will be 1 kOhm or so, and the input will be connected to the mains.

It looks something like one of these:- https://uk.farnell.com/myrra/44268/transformer-10va-15v/dp/1689089

If the original is a main frequency transformer, there may be standard transformers that will work, of you could have an off-board transformer with leads to the circuit board.

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If it is in deed a conventional mains transformer, it should be a nice easy fix.

Hi, I do hope so. I've been looking at these last night. I'll order one, if it doesn't work I'll add to my stock .

Anot

MoAw said:

Thank you, like I said they don't talk to engineers!

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Another example why "Right ro repair" act has to be introduced.

starLED said:

Anot


Another example why "Right ro repair" act has to be introduced.

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Load of crap and a stupid idea - not at all what you think (and hope) it might be.

For a start it will considerably increase the price of everything you buy, modern electronics is so cheap partly because they don't provide spares or service, both of which are VERY expensive to do.

They certainly aren't going to go back to component level repairs, at best it will be replacement PCB's, and manuals without any circuit diagrams in - basically what you get now as a service agent.

So as a customer you approach the manufacturer (most probably a call centre in Egypt or India) and ask to buy a replacement Main PCB and service manual (so you can set it up) for your £400 TV. Certainly sir, the PCB is £380+VAT+postage, and the service manual is £48+postage.

It's a typical example of governments opening their mouths without the slightest idea what they are talking about, or what they are actually saying (just normal government I suppose?).

Nigel Goodwin said:

not at all what you think (and hope) it might be.

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I think that depends on the maker, and possibly country.

eg. Apple have release full service manuals for all their stuff made in the last few years, totally free:

Parts prices are not too bad either:

rjenkinsgb said:

I think that depends on the maker, and possibly country.

eg. Apple have release full service manuals for all their stuff made in the last few years, totally free:

Manuals, Specs, and Downloads - Apple Support

Manuals, technical specifications, downloads, and more for Apple software and hardware

support.apple.com

Parts prices are not too bad either:

https://www.selfservicerepair.com/order

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Interesting that Apple have done so, as (as far as know) they were one of the worst and earliest offenders.

Mind you, as they aren't 'giving' their equipment away, and making vast profits, they no doubt have the ability to do so

Nigel Goodwin said:

Load of crap and a stupid idea - not at all what you think (and hope) it might be.

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No, it's a good idea, and exactly what I think that will be is now underway in EU and USA.
Sure, it's not there yet, but lawmakers are fighting to push this law as people are expecting.
There will be a harsh fight with a manufacturers, though.

Nigel Goodwin said:

For a start it will considerably increase the price of everything you buy, modern electronics is so cheap partly because they don't provide spares or service, both of which are VERY expensive to do.

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I agree, surely it will raise prices, but it would pay off in a long run, since you will not spend on buying new device every two years.
They would just have to provide spares, not service.

Nigel Goodwin said:

They certainly aren't going to go back to component level repairs, at best it will be replacement PCB's, and manuals without any circuit diagrams in - basically what you get now as a service agent.

Click to expand...

EU proposed law that will demand components (IC's, transistors...).

starLED said:

No, it's a good idea, and exactly what I think that will be is now underway in EU and USA.
Sure, it's not there yet, but lawmakers are fighting to push this law as people are expecting.
There will be a harsh fight with a manufacturers, though.


I agree, surely it will raise prices, but it would pay off in a long run, since you will not spend on buying new device every two years.
They would just have to provide spares, not service.


EU proposed law that will demand components (IC's, transistors...).

Click to expand...

Providing spares is VERY expensive - going back a good many years there was legislation that manufacturers had to keep spares for seven years - and the costs of that go on the price of the equipment. Sharp Electronics got round it by pricing CRT's (and later LCD's), which take considerable expensive space to store, at considerably more than the price of the TV, and not allowing service agents to replace them under warranty. I even had a Sharp 25 inch CRT TV, and as a matter of interest I priced a CRT for it - the sets retailed for about £399 - a replacement CRT was £1500+VAT at trade.

This meant they never sold any, so only had to keep a couple in stock, and after seven years they just crushed them - I happened to be there on a course one day, and they had a special skip with a built-in crusher, crushing all the CRT's for disposal.

Presumably you, as well as the EU, don't have the slightest idea of how the electronics industry works? - a manufacturer (such as Sony, or TESCO'S - who are also a 'manufacturer') - order X thousand TV's from the factory, and also order whatever spares they think will be needed over the life of the set. The factory run the production line to create the required number of sets and spares, then the production line is shut down, and reconfigured to make something else. These are all the sets and spares that will ever exist - the factory don't have any spares, they are just a manufacturing facility for a third party.

So obviously Tesco's have a huge spares and facility, where all the spares are kept and service carried out? - I don't think so

You should also bear in mind the manufcaturing life of the chips used, most of those will only have a manufacturing life of a year or two (if you're lucky) so who keeps all those spares?.

EU will force manufacturers to keep spares, because market is over-saturated with electronics waste.
You are talking from the manufacturers point of view, and their logic is like that.
But only big markets as EU or USA have a power to change such logic, and EU is determined to force it.
Manufacturers will have to comply, it's too big of a market to abandon if otherwise.
Latest, they forced Apple to use USB-C standard charger/plugin, and all other manufacturers.

The science community are lobbying governments right now, they are saying Mine the E-Waste and not Earth. Environmental pollution from electronics waste is having a huge impact on people and land, look at what's happening in China.

For information it was a customer services from the company in Italy who answered me.

starLED said:

EU will force manufacturers to keep spares, because market is over-saturated with electronics waste.
You are talking from the manufacturers point of view, and their logic is like that.
But only big markets as EU or USA have a power to change such logic, and EU is determined to force it.
Manufacturers will have to comply, it's too big of a market to abandon if otherwise.
Latest, they forced Apple to use USB-C standard charger/plugin, and all other manufacturers.

Click to expand...

As someone who spent 46 years in the electronics trade as an engineer I certainly know the manufacturers point of view, but I also know the customers point of view. How much more are you prepared to spend on your electronics items?, 50% more?, double? - even more?.

The USB-C standard is pretty well nothing, it made perfect sense, and didn't really cost anything - just stick a USB-C socket on your next model, rather than the old socket - so zero cost to the manufacturers, and no impact on the retail price.