Author Topic: Transformers, 220V AC  (Read 2009 times)

Family_Dog

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Transformers, 220V AC
« on: December 07, 2006, 09:39:27 pm »
I have used them for many years for custom-made transformers & DC chokes. They also manufacture Output Transformers at a reasonable price.


PETER SOURIS AND CO (PTY) LTD (Johannesburg ) tel (011) 493-2042


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-Eric

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Ampdog

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Re: Transformers, 220V AC
« Reply #1 on: December 10, 2006, 12:29:55 pm »
They can also supply 3 sizes of metal end shells to cover the windings for a professional look. They are sometimes slightly more expensive than others, but run a very neat shop (I have inspected).
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GearSlave

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Re: Transformers, 220V AC
« Reply #2 on: December 10, 2006, 09:59:55 pm »
Just for interest sake,

I have all my toroids made by Toroidal Technologies. Also pricey in one off quantities, but if you compare it with what the guys pay overseas for custom toroids, I think we are paying peanuts! As a matter of interest, something I was told recently. You have the option of giving the toroid VPI treatment for an additional 18%. This is required for larger sizes, especially in Class A amplifiers were you have a constant drain on the supply. I'm not too sure about the details of the process, but basically it is an additional step in the process where the windings are forced tighter in a vacuum sealing process. This limits the amount of audible hum that the toroid emits.

chipwelder

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Re: Transformers, 220V AC
« Reply #3 on: December 11, 2006, 06:59:42 am »
Aha that would be useful... that VPI thingy...

CM transformers in Pretoria West... they'll even build you transfromers for Power factor corrected designs, although I think you have to build the rest of the PSU... darn!

Is there truth in the rumour that psu's beyond a certain size has to be power factor corrected? and what is this size - I read up on welders a while ago and  appreciate that they should be so corrected, but I'm sure some of our amps may fall into nearly the same category.... well some of the lucky ones amongst us
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Ampdog

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Re: Transformers, 220V AC
« Reply #4 on: January 14, 2007, 02:13:16 am »
The last post was some time ago - WHERE IS EVERYBODY!

Power factor corrected - not that I know of (I mean for amplifiers). From what I know welders can be quite reactive, but most amplifiers probably not. But I will enquire from someone connected with the City Council electricity department whom I know.
'Miracles' are not contrary to Nature - they are only contrary to our understanding of Nature

chipwelder

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Re: Transformers, 220V AC
« Reply #5 on: January 16, 2007, 02:46:00 pm »
Hi,

I just heard that in the talk given by the Halcro Designer, a web-site dedicated to corrected PSU's and an old welding manual - so it is possibly only true for Australia and UK... So I don't know too much except that and that Corrected power supplies tend to be quite difficult to design for somebody with limited welding/soldering experience...

Electric motors are also quite reactive it seems
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Family_Dog

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Re: Transformers, 220V AC
« Reply #6 on: June 24, 2011, 08:29:37 pm »
Pinched these details posted by Murray (Thanks, Murray!) in the DIY Amp & Preamp thread...

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W.Gardner & Son T/A Toroidal Technologies

Phone: (011) 615 7245
Fax: (011) 615 1800

Address:

2 A Heriot Street
Malvern
2094
South Africa

They're good people, local, and will wind a custom toroidal transformer for you, and as a bonus, they're cheaper than RS.

---


-F_D



-Eric

That Guy in South Africa...
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Ampdog

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Re: Transformers, 220V AC
« Reply #7 on: June 25, 2011, 11:14:56 pm »
This is sure a long-running thread; since 2006. But the subject will always be relevant, as will be the experience of every one for the mutual benefit.

Perhaps in all fairness I should qualify this post with: RANT.

This is now the middle of the year 2011 - and sadly, matters sure have deteriorated. I am at present 'shopping around' for the manufacture of output and power transformers for my 100W valve amplifier (500VA range). NO manufacturer is immediately interested, also those with whom I had business within the last less than a year. E-mails are sent in vain; one has to phone up and sound important, often several times, getting a non-committal reply to start with - they clearly do not even recall or can immediately locate your (several) e-mails sent within less than a month.

To be blunt: Forget about an e-mail request to Souris; they have simply stopped to be interested in small private orders. (I recently had a rather stiff chat to someone 'in charge', with a somewhat arrogant attitude. If it was not that they can also supply end bells with three popular core sizes and their quality is superior ....)  Then I had quite favourable dealings months ago with 'SJ Andrews Electronics', but attention has suddenly waned.

I am hunting for the Garner blokes, but understood that they no longer exist. Dealings/practice with the local CJ Transformers for other than toroids, better go unmentioned. I am also hunting for the successors of previously 'Fanvier', last in Minerva Ave, Lea Glen, Jo-burg. Mr Howard Glass there is/was pleasant and a man of experience. (Gunter Steinhart used them for his transformers.)

And so it goes on; maybe the impatience of my age is setting in - but why must one accept mediocre attention; my money has the same colour as that of others and I have never argued about someone's price. Perhaps the picture is more favourable elsewhere in the nation - one would like to hear about that. Only cost of post in the case of transformers is rather prohibitive. Almost forces me to exorbatant measures like constructing my own facilities as Karel Mars does.

(That leaves cores. In all fairness, I must praise the efforts of AMC [Alloy Magnetic Cores (Pty) Ltd] in Jo-burg. I believe most SA transformer manufacturers use their cores. They have been pleasant to deal with, even winding non-standard C-core widths for me at no extra cost. Even more alluring to set off on one's own....) 
'Miracles' are not contrary to Nature - they are only contrary to our understanding of Nature

tangmonster

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Re: Transformers, 220V AC
« Reply #8 on: June 26, 2011, 10:42:37 am »
This is sure a long-running thread; since 2006. But the subject will always be relevant, as will be the experience of every one for the mutual benefit.

Perhaps in all fairness I should qualify this post with: RANT.

E-mails are sent in vain; one has to phone up and sound important, often several times, getting a non-committal reply to start with - they clearly do not even recall or can immediately locate your (several) e-mails sent within less than a month.


An that is why for the last 3 500va toroidal's i needed i didn't care to spend the extra R80 per transformer to just get it from RS. i get within 4 days at my door. And they are good quality.

My previous project with ordering 4 x 500va's from toroidal technologies cost me 4 to 5 weeks of emails and phone calls and begging.

handsome

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Re: Transformers, 220V AC
« Reply #9 on: June 26, 2011, 12:24:41 pm »
I ordered two filament transformers from Souris less than a year ago and i was not disappointed

tangmonster

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Re: Transformers, 220V AC
« Reply #10 on: September 01, 2011, 11:26:28 am »
Pinched these details posted by Murray (Thanks, Murray!) in the DIY Amp & Preamp thread...

---

W.Gardner & Son T/A Toroidal Technologies



They're good people, local, and will wind a custom toroidal transformer for you, and as a bonus, they're cheaper than RS.


-F_D


Have to disagree.

I currently need an 800va 40 0 40.

toroidal technologies quote excluding vat R989
vpi treatment at toroidal technologies is another 15% more before vat.
Shipping will then add to the above cost with toroidal technologies (R100?)
has 2 to 3 week lead time


rs components excluding vat R888
Rs has free delivery.
4 working days.

undefined.za

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Re: Transformers, 220V AC
« Reply #11 on: September 01, 2011, 11:34:04 am »

Have to disagree.

I currently need an 800va 40 0 40.

toroidal technologies quote excluding vat R989
vpi treatment at toroidal technologies is another 15% more before vat.
Shipping will then add to the above cost with toroidal technologies (R100?)
has 2 to 3 week lead time


rs components excluding vat R888
Rs has free delivery.
4 working days.

Yeah, yeah, so RS wins...

More importantly: what are you putting that 800va into? :D :D

tangmonster

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Re: Transformers, 220V AC
« Reply #12 on: September 01, 2011, 12:16:39 pm »
600W class D amp that is part of my subwoofer upgrade.

using the international rectifier iraudamp modules.

http://www.irf.com/technical-info/refdesigns/iraudamp7s.pdf

Ampdog

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Re: Transformers, 220V AC
« Reply #13 on: September 02, 2011, 12:18:38 am »
And to still continue ....

Since my last post I finally had successful negotiations with SJ Andrews Electronics (Johannesburg). There are at present 12 transformers and 4 chokes on order. Cost for those interested: 500VA C-core power transformer: R890; similarly for a 150W valve output transformer also wound on a 500VA C-core; R500 for a large choke on an E-I core.

(These are not readily commercially obtainable as the design is for my particular requirements, so one cannot easily compare. Even if obtainable overseas, shipping cost would probably be prohibitive because of weight.)
'Miracles' are not contrary to Nature - they are only contrary to our understanding of Nature