I think all these alleged attributes are untrue.
I asked in another Thread when high efficiency was claimed for R core and no one came forward with any evidence.
The exposed "core" may lead to flux/field leakage. Could this result in higher emi?
Rcore are certainly not smaller than toroid. If anything the two sizes I have are bigger than the equivalent toroid.
A toroid transmits interference through the capacitance between the inner primary and the overlaid/outer secondary.
A properly assembled Rcore has an inner primary and an outer secondary on each limb.
In this respect both will have similar capacitance to transmit interference.
Both can have an interwinding screen and both will gain similar benefit with reduced interference when such a screen is fitted and corrrectly connected.
An improperly assembled Rcore could have the primary on one limb and the secondary on the other limb. This will give much inferior overall performance as a consequence of separating the windings. The gain is much reduced interference transmission, which may better the EI and Ccore types.
Hi to All !
may I only ask why for low VA nobody likes EI types ?
Lately I have been watching some videos on repairs of linear lab power supplies. EI type is everywhere. It looks to me like the most common solution.
Why ? they leak ... vibrate ... are not efficient ... spit out EMI ... big and heavy ... and still they are used in almost every lab psu.
Is it a matter of cost ? I mean they are used because cheaper than the other types ?
Thanks a lot, gino
may I only ask why for low VA nobody likes EI types ?
Lately I have been watching some videos on repairs of linear lab power supplies. EI type is everywhere. It looks to me like the most common solution.
Why ? they leak ... vibrate ... are not efficient ... spit out EMI ... big and heavy ... and still they are used in almost every lab psu.
Is it a matter of cost ? I mean they are used because cheaper than the other types ?
Thanks a lot, gino
This is, sorry, nonsense. It was one of the design features Rcores were invented for. There are more than enough audio products where Rcores are mounted very very close to input circuitry apparently without consequences.
http://www.shilchargroup.com/electronics-telecom/r-core.aspx?pg=pr&sid=rc
OK, so you own 2 and can tell that they are all not smaller than toroids ? Please compare the same VA ratings of various sizes Rcore transformers with same VA rated toroids. I stock various sizes and also have experience with various sizes toroids. Rcores have many benefits, too bad that availability is bad. They are a very good choice in audio.
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Hi ! an example of transformer used in a lab power supply here from 9:15
https://www.youtube.com/watch?v=a24Fv45FuOc
this is a quality power supply I guess. Why not a toroid instead ?
https://www.youtube.com/watch?v=a24Fv45FuOc
this is a quality power supply I guess. Why not a toroid instead ?
That is not a standard EI but a type I don't know the english name for. It has similar features as Rcore. Philips used to produce these many years ago as premium quality transformers in various equipment.
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Hi ! thanks a lot !
yes it looks particular not like the normal EI types.
So it seems that transformers are a very critical part ...
It looks like the two windings are separated by the way.
Differently from toroids where primary and secondary are one of the top of the other.
They are concentric.
Maybe there is no English name because Philips is from Holland.
Kind regards, gino
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Sorry my reply "cost" was wrong as it seemed an EI type at first. The type in the Agilent PSU has the sheets under high pressure kept together by a kind of "strangling" band. I think the english name is C-core transformer. These have low flux leakage.
Toroids are worst choice in audio but as they can be found everywhere, cost is low and mounting is easy often the strict demands of audio users are suddenly somewhat softened 😉
First choice are R-core/C-core, second choice is EI and third choice is toroid |(in terms of technical quality for audio devices). Why not go for the best ?
Toroids are worst choice in audio but as they can be found everywhere, cost is low and mounting is easy often the strict demands of audio users are suddenly somewhat softened 😉
First choice are R-core/C-core, second choice is EI and third choice is toroid |(in terms of technical quality for audio devices). Why not go for the best ?
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Thanks again ! I have found them. They are very nice and similar to R-core actually. I see that this construction is very popular for output transformers.
I like them a lot.
This is a very very important point to fix for me. I can tell you that I have in mind to replace them in all the units that I already like.
I do not know why but I felt this. They are both nice looking and nasty for audio. I will never buy one again.
Of course ! especially when the difference in price is reasonable.
I am waiting for my 1st R-core. It should be here soon.
I have just one problem about how to wire the 2 secondaries in parallel.
Is there a phase issue ?
Thanks a lot again, gino
Of course there is a phase issue but I haven't seen one yet that has not the right markings on it.
Yes. I have seen marks on the transformer body but the 4 secondary leads are like 2 yellow and 2 white ...
But one lead will be phase and the other return (I do not know the exact terminology). I cannot see which lead is the phase.
I cannot understand which of the two yellow and white leads I have to connect together for having the correct phase.
Color aside they look identical.
I will post a picture because looking in the basement I have found a R-core in a preamp I do not use anymore.
I will post a picture to explain what I mean.
This phase issue is driving me mad. Never understood phase .. only Live and Neutral on mains.
Never touch Live terminal.
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Never touch the Neutral either!
If you don't understand mains systems you should not be playing with transformers.
If you don't understand mains systems you should not be playing with transformers.
Hi ! Thanks for the advice. Found this ...
I guess key point is that non degraded correctly wired installation ?
I wonder if I can check the difference in potential between the neutral and ground on a mains outlet. Also to check if I have a correctly wired installation at home 🙄
Regards, gino
The key point is don't touch the neutral,
to even consider doing so is rather stupid. I would suggest getting to know all the regs. we have to work to in the professional world (non DIY).
to even consider doing so is rather stupid. I would suggest getting to know all the regs. we have to work to in the professional world (non DIY).
Thanks again for the helpful advice. I was clearly underestimating the risk.
I was aware of the danger touching Live but non Neutral. Very good to know. I should really use a safety breaker on my testing bench.
If only I knew which one to buy 🙄
Maybe a breaker is only what is needed to be safe.
Please read and understand the following (norwegian) links before attempting to do measurements. In Norway most houses have a net called IT where both phases are separated from PE (protected earth). Touching either one of them will give you shock if your body also are in contact with earth. Measuring from PE to either phase should give you roughly half 230V in a IT-net. You should check if your house have IT or TN net.
https://no.wikipedia.org/wiki/TN-nett
https://no.wikipedia.org/wiki/Nettsystem
Hva er forskjellen på 230V og 400V
https://no.wikipedia.org/wiki/TN-nett
https://no.wikipedia.org/wiki/Nettsystem
Hva er forskjellen på 230V og 400V
Hi and thanks a lot indeed !
I will check it this evening as soon as I will be back home.
I like the use of schuko plugs a lot. And the robustness of the plants due to the electric heating solution.
Thanks a lot again.
Kind regards, gino
"I like the use of schuko plugs".
Two pins. Which one is the Neutral? And, would you bet your life on it?
Two pins. Which one is the Neutral? And, would you bet your life on it?
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Yes you are right ... but I am coming from this one here
the schuko design gives a much much better feeling regarding the quality of contact.
I mean ... when you plug in a schuko you understand that is not going anywhere ... that it will stay firm in place.
Impressive the matching between the plug and the receptacle.
But yes ... I have still to bet on one pin or the other ... 🙄
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Compared to British clunkers and the terrible US mains plugs the "Schutzkontakt" aka Schuko and CEE form connectors are safe and good. Reliable connections, first PE is connected and then L and N but no predefined L and N. Well, we can apparently live with that 😉
BTW there are 2 pins (L and N) and PE. In my profession we rarely have problems with Schuko except when overloaded which only can happen when someone does something against regulations (so mainly professional guys 🙂) We experience more problems with the US plug. Current is higher as voltage is half and the design is awkward. British plugs are also safe and they're fused but they're clunky. There is a reason many European countries embrace Schuko although there are differences like the Swiss, Italian and Danish versions. Danmark is famous for its different Schuko system as it accepts others Schuko connectors but plugging in a danish connector in a normal Schuko will lead to damage... It may seem a simple task designing a mains connector but I bet there went a lot of thought in the design like most stuff that has been designed in Germany.
BTW there are 2 pins (L and N) and PE. In my profession we rarely have problems with Schuko except when overloaded which only can happen when someone does something against regulations (so mainly professional guys 🙂) We experience more problems with the US plug. Current is higher as voltage is half and the design is awkward. British plugs are also safe and they're fused but they're clunky. There is a reason many European countries embrace Schuko although there are differences like the Swiss, Italian and Danish versions. Danmark is famous for its different Schuko system as it accepts others Schuko connectors but plugging in a danish connector in a normal Schuko will lead to damage... It may seem a simple task designing a mains connector but I bet there went a lot of thought in the design like most stuff that has been designed in Germany.
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Hi !
first of all i share your appreciation of Schuko. I like how the plug match the recessed receptacle.
However i am attaching a picture of the transformer i am using.
I would use both the secondaries for double current if only i knew how to wire them in parallel correctly.
But 15V/1A is enough for my need. It is powering a small headphone amp through a DC umbilical.
The sound is quite good.
And i think this transformer is very cheaply built.
Anyway i like a lot what i am hearing.
Thanks a lot again, gino
first of all i share your appreciation of Schuko. I like how the plug match the recessed receptacle.
However i am attaching a picture of the transformer i am using.
I would use both the secondaries for double current if only i knew how to wire them in parallel correctly.
But 15V/1A is enough for my need. It is powering a small headphone amp through a DC umbilical.
The sound is quite good.
And i think this transformer is very cheaply built.
Anyway i like a lot what i am hearing.
Thanks a lot again, gino
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