Re: Induction kWh meter theory

On Mon, 10 Jul 2006 21:55:45 +0000, Christopher Tidy
<cdt22NOSPAM@xxxxxxxxxxxxxx> wrote:



Thanks very much. That's a nice explanation. Do you know why the
designer might have chosen the interesting shape of core shown in my
earlier post? I know there are several variations of this, but they all
see to have one three-legged core and one two-legged core.

Best wishes,

Chris

In all cases it will be so that the currents induced in the disk by one
winding are circulating in the field produced by the other winding. in the one
shown in your photos the currents induced by the centrally placed current
winding circulate under the poles of the voltage winding.

The forces produced follow the " Fleming's left hand rule". hold our left hand
so that the thumb, first finger and second finger are at right angles to each
other. then you have the directions given by:_

thuMb=motion
First finger=field
seCond finger=current.


So you can see that with the voltage coil generating its field through the two
sets of poles (down through one and up through the other, and the current
induced by the field from the current coil (circulating the pole piece) going
into the screen/paper on one side and out of the screen/paper on the other
side, that the force generated in the disk will be in the same direction at
each of the outer poles.

Also you may have noticed that the currents induced by the field from the
voltage coil can interact with the field from the current coil (why not, the
same rules apply to all the fields and currents involved). If I haven't
completely lost the plot (quite possible), the forces produced by this
combination of fields and induced currents, add up in the same direction as
the other lot.

Does your head hurt yet? mine does:-)

Mark Rand
RTFM
.

Relevant Pages

  • Re: Smps Toroids on a Ground Plane
    ... Could I blanket my toroid with some foil and ground the foil? ... contained in the core. ... high dv/dt node at one end and a lower dv/dt node at the other. ... Now I switch to that special winding technique.. ...
    (sci.electronics.design)
  • Re: DC magnetisation of transfromers and chokes.
    ... V is the voltage in Vrms across the winding, ... Afe is the core area in sq. ... Is µe just µ with ungapped material? ...
    (rec.audio.tubes)
  • Re: Flyback regulator / transformer problems.
    ... I have essentially the same cct with a different transformer, and feedback components changed for a 5Voutput.The other outputs are not regulated, I have only wound the 5V winding and populated the pcb with the required components for 5V out so far. ... The drain voltage of the FET is going WAY to high.Up to about 800V spike. ... The switching frequency is about 100KHz.I am using a EC35 core with N27 material with a 0.5mm gap. ... drive gate with pulse generator at about ...
    (sci.electronics.design)
  • interesting OPT winding comments
    ... DIY output transformer info site - Click HERE for Original Thread ... Site doesn't mention toroidal xfrmr winding techniques though. ... and cover near 360 degrees in one sweep around core per winding. ... does not benefit in toroid case (since leakage inductance is already ...
    (rec.audio.tubes)
  • Re: To airgap or not, thats the question.
    ... driver amp stages and the low input impedance of the output transistors. ... But if you can estimate the winding window, and assume all the windings use ... window size; assume a wasteless core. ... However, many OPTs for old radios would have a P of about 245 ohms dcr, ...
    (rec.audio.tubes)