At 08:31 PM 5/6/2002 -0700, you wrote:
>Yes, that is what I thought also, Jeff. If the flux density doesn't
>increase under load, then how is energy transferred from
>primary to secondary?
No, Tom is correct. Flux density is a function voltage, not current. If you
look up the voltage equation for transformers you'll see that current is
not involved. Ampere-turns is what determines the mmf in the core.
Flux density remains essentially constant at all loads.
Phil
>Mike, W4EF.....................
>
>----- Original Message -----
>From: "jeff millar" <wa1hco@adelphia.net>
>To: <W8JI@contesting.com>; "Ian White, G3SEK" <G3SEK@ifwtech.co.uk>;
><amps@contesting.com>
>Sent: Monday, May 06, 2002 7:22 PM
>Subject: Re: [Amps] Rectifier diode strings
>
>
> > Whoa...flux density comes from Ampere-Turns, not Volt turns.
> >
> > But, overall an excellent discussion.
> >
> > jeff, wa1hco
> >
> > ----- Original Message -----
> > From: "Tom Rauch" <w8ji@contesting.com>
> > To: "Ian White, G3SEK" <G3SEK@ifwtech.co.uk>; <amps@contesting.com>
> > Sent: Monday, May 06, 2002 2:12 PM
> > Subject: Re: [Amps] Rectifier diode strings
> >
> >
> > > > Unless I misunderstood Tom's point about mains transformers saturating
> > > > at 1.3-1.4 times normal primary voltage, surely that would only apply
> > > > at full load? The main risk to the rectifiers is more likely to be
> > > > during RX periods, when the load is at a minimum but the DC voltage is
> > > > at a maximum. I don't believe the saturation argument would apply
> > > > then, would it?
> > >
> > > Yes, saturation applies. Remember what it is. The core can only
> > > obtain a certain flux density, and that flux density relates only to
> > > the volt-turn of the magnetizing winding. Flux density is the same at
> > > full load or no load, ignoring small differences caused by resistance
> > > in the primary and power mains.
> >
> >
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> >
>
>
>
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