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-   -   Imported goods and UK Mains Voltage (http://www.diyaudio.com/forums/power-supplies/218492-imported-goods-uk-mains-voltage.html)

noggindoo 25th August 2012 08:58 AM

Imported goods and UK Mains Voltage
 
Hi All
My first post and venture in to integrated Hifi tube amps. I live in the UK and unfortunately cant afford to purchase a UK made amp so looking at imports which seem to all be for 220V.
I have asked on seller who informs that i should use a voltage converter with them.
Can anyone tell me if this is correct I know nothing about electronics and dont want to buy something then be unable to used it or have an expensive conversion cost on my hands - what are these voltage converters ??
Thank You

DF96 25th August 2012 09:32 AM

Many modern '220V' units will be fine on our mains supply, which is officially 230V but actually more like 240V in most places. Be careful about cheap Chinese stuff, as the transformers might saturate on 240V.

AndrewT 25th August 2012 01:04 PM

most transformers are manufactured to the universal 115/230Vac standard.
These transformers should all operate on the full UK range of 216Vac to 254Vac.

But as Mooly has siad, some substandard transformers may be in the market place.
I don't know how you tell them apart prior to buying.

After you have bought, you will find out if the transformer is "hot". That is a sign that it is drawing too much current on light loading.
But how do you convince the retailer that their transformer is substandard when the only evidence is "hot"?

noggindoo 25th August 2012 01:28 PM

Ok, Thank you for the replies.
Thats helpful to know.
Unsure what is meant by saturate
Would it be worth getting a voltage converter then to be on the safe side or just plug in and see how hot the transformers get? Presume that they should be warm but not hot also if
I plugged an amp in what happens if it does not like our 240V mains will it blow a fuse or completely damage the amp.

I know it does appear that you may take a chance ordering from abroad and I realize that effectively I wont have a guarantee etc and be liable for import duty. Not knowing about electronics as well makes it that little more of an adventure as well.
I am keeping my eyes open for the direct import brands on the bay and other sites etc as I may be lucky and find one already in this country and in my budget, although I do wonder if some items advertised as saying items are located in UK actually are.

Anyway and thanks for your input

ashok 25th August 2012 02:19 PM

A 220V trafo on a 240 V mains line will not blow a fuse. It will start to get hot pretty quickly. Most get warm after 20 minutes or so. This one will get very hot quickly. You should also worry about the rectified dc voltage on the circuits.

You could use a 220v to 240 V auto-transformer. This is less expensive than an isolated 220/240 v transformer as part of the winding is shared by the primary and secondary so it uses less copper.

jean-paul 25th August 2012 02:26 PM

So I am not the only one wondering why Chinese electronics companies think the world is divided in 110 V and 220 V. This was something 20 years ago. Chinese domestic mains voltage is still 220 V though.

If only they would design in an extra winding for 230 or 240 V (most countries silently raise mains voltages higher than 230 V) and all would be happy...

When I think of it: 4 terminals would be best. 0/115/230/240 V. I am just changing an old US device from 1988 that has it done like that. Couldn't be better.

noggindoo 2nd September 2012 05:53 PM

Hi everyone
Just to say the amp has turned up, finally got round to trying it out today and pleased to say
that so far it seems ok, i have run it for an hour and the transformers are just tepid.
So will keep you posted if something happens ...
mean while i want to start reading does and don'ts with these amps and aslo what tube are and how they work.
Noggindoo


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