The voltage induced is proportional to N * dP/dT, where P is total flux that the winding encloses, namely the center leg of the core. Since the number of turns and the frequency and the core dimensions don't change, the induced voltage tracks flux density.
You are right if loading sec2 has zero affect on the voltage observed at sec1, ie, all transformers have perfect cross-regulation.
Try it.
John
Then the only proper way to get where you want to be is by using a toroidal core.
In your scenario, it should not matter where the monitor winding goes, as long as it is in the flux loop path and makes at least one turn around that. Not everything is an E-I core configuration either, as it appears you assume, with your 'center leg' remark. That is also whay I stated that the right way is to use a toroidal core to be certain one is observing ALL of the flux.
What I want? What's that?
Most power transformers wrap all the windings around the same core, whatever its geometry. So what the primary induces into the core material, the secondaries see. The flux that matters is enclosed by all the windings [1]. So the voltage induced into an unloaded secondary is a good indicator of the flux density that matters, namely the flux that the windings actually induce and use; this concept has a pretty high f-sub-D [2] factor.
The question was whether loading the secondary of a power transformer increases or decreases the core flux density. Which way do you vote?
John
[1] with minor footnote for leakage fields. Microwave oven transformers, for example, are designed to have lots of leakage. [2] "duh"
th
y 1
h ,You seem to think that placing it elsewhere risks missing some of the flux. There is no way to miss ANY of it with a toroid core.
No, John. ALL transformers MUST have any winding it wishes to 'transform' voltage to on the same core.
There is ONE secondary. An additional winding would be a tertiary winding.
No. ALL of the flux is 'enclosed' by the core.
Yes, voltage rises as flux density increases in the open feedback winding. They are no longer open once they are being "read", however. It is not linear, and has to be modeled on a per transformer design basis.
It decreases, but is tied to the envelope of the hysteresis loop it follows. Of course one wants to design for operation behind the permeability knee on the B-H curve..
Don't be silly. Even toroids have leakage flux. But that's entirely off the main point.
I don't think my Fluke loads down a power transformer secondary many PPMs. As much as it might, it's still linear, so the voltage reading still tells me whether the flux increases or decreases as I do things.
Good. We have one vote for "decreases."
Two more ways to address the question:
A little playing with a real transformer, a variac, some resistors, and a scope can be educational.
John
Standard terminology is to refer to all the power-delivering windings as secondaries. This terminology is used by the major transformer manufacturers.
See "multiple secondaries":
They are coils of wire wrapped around the common magnetic core. That's all that matters; the rest is just words.
John
-- http://www.youtube.com/watch?v=d2FT4FprxDg JF
s
acturers.
63The moral? "Tell that to the humbuckers!" Just words indeed!
snipped retarded mike crap.
Grow up, you immature little goddamned bastard.
Ever hear of Obamanomics?
You had to re-quote the entire retarded little bastard's abusive horseshit post? Did that make his *it* better?
The way I see *IT*, he is the only one posting *IT*s in the group at all. Him and his retarded butt buddy greegor.
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