Low Voltage Transformers - UK Vintage Radio Repair and Restoration Discussion Forum

ALANS ANITAS · 22nd Dec 2010, 12:05 am

Hi

I have several mains electric clocks with o/c coils. As rewinding a 240volt coil is not very practical, safe,or possibly illegal I have decided to use a low voltage coil, the reccomended supply is a wal-wart type plug in transformer. But where can you get one? The waveform need not be pure sine wave,but does need to be 50Hz. Plenty of "dimable electronic transformers" are listed on Ebay,but I would assume these are a type of switched mode supply,and not suitable. Plenty of DC units are available but the cases are usually welded closed,so removing the smoothing components may damage the case.
Can anyone point me in the direction of a supplier?

ALAN

jimmc101 · 22nd Dec 2010, 12:59 am

Try searching for '12vac adaptor'
http://shop.ebay.co.uk/?_from=R40&_t...=12vac+adaptor
Brings up 'normal' plug-in transformers.

Jim

DAVEHALL · 22nd Dec 2010, 2:15 am

Have you looked in Maplin ?

ALANS ANITAS · 22nd Dec 2010, 3:54 am

Thanks Jim and Dave, I was using the wrong search parameters. A number of those on Ebay seem suitable. Maplin also have a couple, but as usual are rather expensive.

Regards

ALAN

ppppenguin · 22nd Dec 2010, 8:28 am

Hack open a normal DC wallwart and take out the rectifier etc. Need to make sure it's a genuine transformer, not a switchmode, but that's obvious from the weight.

glowinganode · 22nd Dec 2010, 9:36 am

Don't forget doorbell transformers. These often have multiple output voltage tappings and inherant short circuit protection.
Rob.

22nd Dec 2010, 12:05 am	#1
ALANS ANITAS Rest in Peace Join Date: Jun 2006 Location: North West Northamptonshire, UK. Posts: 346	Low Voltage Transformers Hi I have several mains electric clocks with o/c coils. As rewinding a 240volt coil is not very practical, safe,or possibly illegal I have decided to use a low voltage coil, the reccomended supply is a wal-wart type plug in transformer. But where can you get one? The waveform need not be pure sine wave,but does need to be 50Hz. Plenty of "dimable electronic transformers" are listed on Ebay,but I would assume these are a type of switched mode supply,and not suitable. Plenty of DC units are available but the cases are usually welded closed,so removing the smoothing components may damage the case. Can anyone point me in the direction of a supplier? ALAN

22nd Dec 2010, 12:59 am	#2
jimmc101 Heptode Join Date: Mar 2009 Location: Portsmouth, Hampshire, UK. Posts: 674	Re: Low Voltage Transformers Try searching for '12vac adaptor' http://shop.ebay.co.uk/?_from=R40&_t...=12vac+adaptor Brings up 'normal' plug-in transformers. Jim Last edited by jimmc101; 22nd Dec 2010 at 1:01 am. Reason: Fixed link

22nd Dec 2010, 2:15 am	#3
DAVEHALL Retired Dormant Member Join Date: Jan 2010 Location: Coventry, Warwickshire, UK. Posts: 339	Re: Low Voltage Transformers Have you looked in Maplin ?

22nd Dec 2010, 3:54 am	#4
ALANS ANITAS Rest in Peace Join Date: Jun 2006 Location: North West Northamptonshire, UK. Posts: 346	Re: Low Voltage Transformers Thanks Jim and Dave, I was using the wrong search parameters. A number of those on Ebay seem suitable. Maplin also have a couple, but as usual are rather expensive. Regards ALAN

22nd Dec 2010, 8:28 am	#5
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: Low Voltage Transformers Hack open a normal DC wallwart and take out the rectifier etc. Need to make sure it's a genuine transformer, not a switchmode, but that's obvious from the weight.

22nd Dec 2010, 9:36 am	#6
glowinganode Octode Join Date: Apr 2009 Location: Aylesbury, Buckinghamshire, UK. Posts: 1,522	Re: Low Voltage Transformers Don't forget doorbell transformers. These often have multiple output voltage tappings and inherant short circuit protection. Rob. __________________ We have done so much, for so long, with so little, we are now qualified to do anything with nothing.