Selectronic Rcore Transformers

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I'd suggest looking for the UL mark on the transformers - since the firm is UL registered it is likely to be on the transformer.

Have a look at the EU list of UL marks possibly one of these marks will be on your transformers: http://www.ul.com/global/eng/pages/corporate/aboutul/ulmarks/mark/#europe

Also note that the pdfs show that these R-core lines don't follow the black=hot, white=neutral convention. In any event it is not critical. The best advice I can give would be to orient the connections to give the least leakage to chassis with the safety ground lifted and measuring the leakage current between the transformer and safety ground.
 
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They don't carry a UL nowhere, I look at one 50VA model as we post. Primary wires have 22AWG 105C 300V and yellow screen wire 20AWG 105C 600V. American Wire Gauge can be another clue?

It could be.. :D The manufacturer is reputable so I wouldn't think there are any big issues with these transformers. I figured they might carry the UL recognized designation, only transformers that I've seen that carry an actual approval are fully assembled isolation transformers. IIRC transformers don't get individual approvals under UL or CSA.
 
Bottom left wire is the Black, bottom right is the White primary connection.
Now which is which ? :clown:
 

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hmm haha the thing is symmetrical there is beginning and end on this or not? but going by my reading, if thats the right way up the right wire would indeed be the beginning wouldnt it?. it would be quite an achievement to make an RCORE that didnt pass isolation standards, the windings are completely separate.

the grain is symmetrical too yes?

if you flip it over its axis, it looks exactly the same in the other direction
 
Not seems a Shilchar R-Core sold by Selectronic

It's the 500VA/2x24Vac model, has 4 windings per secondary.

(me long-time Selectronic customer, the Ronchin shop is only a 2-hour drive from my place. I go shopping in Lille several times a year, mostly French food stuff, for over 20 years. Also manchego & chorizo, is much cheaper and/or better there)
 
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The grey wires on the top left and top right are the wires of the secondaries.
8 grey ends left, 8 grey wire ends on the right.

Each secondary on a bobbin is made up from 4 parallel windings, one on top of the other.
The wires for the secondaries can be thinner that way, which is easier to wind, and tighter.
For a perfect R-core, one bobbin should be exactly the same as the other one.

The two yellow wire ends between the grey ones on the top are the ends of the primary windings, meeting point is the ground.

So bottom left and right : Black & White
Top middle : Yellow
Top left ;
4 on the left :Grey
4 on the right :Red
Top right ;
4 on the right : Purple
4 on the left : Blue

Under the brown paper layer around the bobbins is a square piece of plastic with solder pads.
The colored external wires are soldered there, together with the ends of the windings.

Toroidals have been the standard here since the late '70s, first commercial products with R-cores from these parts are from the late '80s, around the time i first started dabbling with R-cores (in case you wonder why i'm dissecting R-core transformers)

(cheese or meat, i like everything Spanish, Catalan from Canet in the family since the late '70s. I'm more of a cheese hater, despite having eaten cheese with worms once, but Manchego is the No1 cheese in the world for me)
 
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thanks for the confirmation Jacco, I have recently started to see what all the fuss was about thus my purchase for my dac, my power amps are all going fully regulated switching for experiments, but playing with Rcore options for low level clock and analogue stages in my dacs, with batteries for the rest

have you tried their 'R-toroidal' at selectronic?
 
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I think the point is, if made correctly, there is nothing to worry about

I also love chorizo, there is a local butcher who makes his own organic stuff, with smoked paprika mmmm

If made correctly don't have hot & neutral:confused:?

With all my respect to your local butcher surely not as good as our chorizo, it seems like the attached pic?
 

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