In message , gareth
writes
"Brian Morrison" wrote in message
k...

It's the DC resistance that limits the primary current once the core
is saturated, not the inductance.

When the core is saturated the effective inductance is zero. Think
about the B-H loop diagram for a transformer.

You misunderstand.

I was referring to the saturation of the current, which is limited by the
secondary load.

It's the core which saturates. It can start to saturate without any
secondary current being drawn. If the transformer 'runs out of'
inductance, the primary current can go sky high, as it is essentially
limited by the primary resistance.
--
Ian

"Ian Jackson" wrote in message
...
In message , gareth
writes
"Brian Morrison" wrote in message
. uk...

It's the DC resistance that limits the primary current once the core
is saturated, not the inductance.

When the core is saturated the effective inductance is zero. Think
about the B-H loop diagram for a transformer.

You misunderstand.

I was referring to the saturation of the current, which is limited by the
secondary load.

It's the core which saturates. It can start to saturate without any
secondary current being drawn. If the transformer 'runs out of'
inductance, the primary current can go sky high, as it is essentially
limited by the primary resistance.

You are discussing magnetic saturation. I was discussing the current
saturating to the limit brought on by the secondary load.

Although the I=E/R relationship is normally presented as instantaneous,
it is not, and it takes a finite, although in finitesimal, time to reach the
value.

Likewise, in my comments, it takes some small time for the secondary current
to
reach that value, to saturate, in other words.

Consider a simple circuit of battery, switch and resistor; how does the
battery "know" how much current to flow before it has "encountered" the
resistor?

Perhaps a poor choice of wording on my behalf, when I did not
anticipate your "susceptance"? :-)

But this is (hopefully!) a gentlemanly chatty group and chatting on civilly
should always iron out such misunderstandings.

"Ian Jackson" wrote in message
...

It's the core which saturates. It can start to saturate without any
secondary current being drawn. If the transformer 'runs out of'
inductance, the primary current can go sky high, as it is essentially
limited by the primary resistance.

Actually, in theory, limited by the primary as a now-air-cored inductance,
but in practice by that resistance.