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In Reply to: Re:may we pick your brain Victor K posted by ben on February 21, 2000 at 10:40:05:
***speaking of transformers what is strength and weaknesses of EI v. C core v.double C core v. cut core v.toroidal for both power and output. At what point do they saturate, what is their speed & responsiveness and what is their freq. response typically. I know their are a lot variables so feel free to speak as generally or specifically as you like. many thanks for your valuable contributions to this groupOne way to look at it is from the position of an "ideal component". It is often repeated that the closer a component is to the ideal model, the better it is. Few people would intentionally introduce in the signal chain a less-then-ideal thing.
If you take this approach then toroid wins hands down. Of the three types above it has the lowest flux leakage and the best primary-to-secondary coupling. Think of flux leakage as a blood flow thrugh your body - the less you lose the healthier you are. A toroid is much closeer to an ideal transformer than the other two ( I lump the two C-cores together, and I am not sure what you mean by the cut core, I presume it is still a C-core).
Because of its being closest to ideal, it is also most efficient, meaning the lighest and smallest for the same function and power rating. It also contaminates the surrounding area with stray magnetic fields least of all.
The main reason the toroid is not used more often is of course, its cost. It can be as high as double of the cost of a traditional E-I type.
The C-core parts are essentially lower cost toroids and are placed in between the two types. These enjoy many benefits of the toroidal transformers at much lower cost. They do lose some qualities, of course. But because they are highly manufacturable and can be configured many different ways (depending upon the bobbins shapes), they are very popular, mostly in Asia and Europe - have been for decades.
If your main concern was bandwidth, then using a toroid would provide for the widest one - because the leakage inductance is the lowest.
In my view (and I put my money where my mouth is), all high end products simply should have toroidal power transformers. Magnetically shielded ones.
When it comes to an optput tranny, there it is all about a particular sound the designer is trying to achieve, and the transformer is a significant sound-shaping tool. So the E-I type has more right to exist in this particualar area.
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Follow Ups
- Re:may we pick your brain Victor K - Victor Khomenko 11:52:54 02/21/00 (3)
- Re:may we pick your brain Victor K - Joseph 18:52:48 02/21/00 (2)
- If I were a DIY'er... - Victor Khomenko 04:36:48 02/22/00 (1)
- Re: If I were a DIY'er... - Joseph 16:57:23 02/22/00 (0)