bill.....
** But only if the core is being driven to the same magnetisation level.Cleary not the case with wide band transformers fed with a constant input voltage.
** Not true for the same transformer.** Never said anything like that.
Try posting Qs under my actual words pal - it's standard usenet practice and common sense.
.... Phil
But these aren't wide band transformers, but supply frequency transformers. There's a lot of interwinding capacitance, which you do have to drive, and that takes more current when you move above supply frequencies.
And the hysteresis losses happen every time the core is driven through it's magnetic field range. Do it more often, and you dump more heat in the core, which you have had to extract from the circuit driving the transformer.
What makes you think that?
You said something like it
"Toroidal types work as well or better than E-cores as wide band audio transformers, without the need for layered windings."
-- Bill Sloman, Sydney
It is a neat idea, and can work, but there are potential problems - which is why the world doesn't use re-purposed power transformers for every transformer job.
-- Bill Sloman, Sydney
** I am not going to play your silly game any longer.
Since the valve era, laminated steel core transformers have been used to cover the audio frequency band for a host of applications - so they work very well and to beyond 10kHz.
Toroidal core types are just another example with some advantages and some differences.
.... Phil
Don't be too sure, power transformers often have rather high leakage inductance, which is a killer for high-frequency response. Audio transformers use special interleaved winding techniques to solve the problem. But a pair of split secondary windings could/might be wound in a way that'll do the trick.
--
Thanks,
- Win
** Certainly true if the primary and secondary are wound on separate halve s of a bobbin. Ones that have the secondary wound directly over the primary are much better coupled and toroidals are the best with the secondary woun d all over the primary, all around the core.
** Almost guaranteed to be bi-filar wound in case of toroidals.
.... Phil
Den 23/03/2016 kl. 02.54 skrev Robert Stevens:
How about paralleling two transformers:
Use "middle" of 4 and 8 ohm; ca. 6 ohm.
Use low-pass (two inductors) to couple the "LF" transformer to load and amp. L=R/(2pi*f) ca.= 6/(6.3*400) = 2.4 mH
Use high-pass (two capacitors) to couple the "HF" transformer to load and amp. L=1/(2pi*f*R) ca.= 1/(6.3*400*6) = 66 uF
Remember a resistor at output, to dampen possible high voltage, if output is unconnected and primaries are driven with active amp.
Glenn
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